A
Abnormal glow, 570
Abrasion, 424–426, 1073–1076, 1104–1105
Abrasive particles, 425
Absolute cathode gain, 639
Accelerated current-cycling tests, 345, 363–365
Accelerated testing, contact erosion measurements, 993
Acceleration factor (corrosion), definition of, 158–159
Accelerator Pedal Position (APP) sensor, 541
Account vaporization of metal, 630
ACSR conductors, 327
AC-1, -2, -3, -4, testing, 794–795
AC testing vs. DC testing, 978–979
Activated adsorption sliding contacts, 1053, 1054
Activation of switching contacts, 526, 588, 622–624, 643, 1006–1014, See also Contact activation
absorption ion site limitation, 622
activation curve, 622, 1010–1011
activation process, 1007
arc duration, 622
arc formation, 1007
arc motion, 1012
closed contacts, 1009
contacts after arcing, 1009
contacts no arcing, 1009
critical exposure, 1011
detection, 1014
ranking metals and organic activants, 623
Adhesive bond, 1102–1103, 1111
Adhesive forces, 1103
Adhesive wear, 439, 481, 1070, 1157–1158
in gold electrodeposits, 422
mechanism, 415
Adsorbed moisture films, 1170
Adventitious lubrication, 1121, 1124
Aerobic lubrication, 1141
anaerobic vs., 1121
wear debris, 1124
AES, See Auger electron spectroscopy
AFCIs, See Arc Fault Circuit Interrupters
AFM, See Atomic force microscope
A-fritting, See Fritting
Ag–CdO contacts, 605, 645, 655, 771–773, 884–906
Air blown cleaning, 225
Air-break contactors, 794
Air contaminants, expected maximum average value for, 126
Air cylinder switch, 699
Air pollution, 126–128, 190, 1118
Alternating current arcs
reignition measurement, 996
Alternating current circuits, arc interruption in, 597–600
arc plasma and dielectric reignition, decay of, 602–603
arc quenching, 798–802, 808–814
current limiting technique, 608–609, 820–822
instantaneous dielectric recovery, 600–602, 799–800
effect of current level, 599, 800
effect of arc chamber material, 801
low frequency circuits, 609
mega and giga hertz circuits, 609–612
reignition
dielectric, 602
thermal, 603
thermionic, 603
transient recovery voltage, 598, 798, 831
Alternating current erosion, 770–773
Alternating current operation, 780
Alternators, brush applications, 1088
Altitude-treated brushes, 1084
Aluminium–copper, mechanical properties of, 294
Aluminum, 385
coating of, 331
oxidation kinetics of, 258
Aluminum-aluminum contacts
current–voltage characteristics from, 56
Sharvin resistance role in, 86–87
voltage-temperature relationship for, 61
Aluminum-base connectors, 23
Aluminum–brass interfaces
equivalent contact radius in, 39
high resistivity intermetallic layer in, 40
and intermetallic compounds, 30–33
intermetallic growth at, 42–45
fretting damage, 285
properties of, 241
stress relaxation of, 304
Aluminum connections, fretting in, 283–285
Aluminum contacts, breakdown of classical electrical contact theory in, 84–87
Aluminum-copper bolted joints, relative motion effect in, 278
Aluminum–copper interfaces, 32, 33
Aluminum oxide growth rate and electrical resistivity, 53–56
Ambient effects, on arcing contact surface, 665–667
Ambient temperatures, testing at, 982
Ameliorating frictional heating, effective in, 1167
American Society of Testing and Measurement (ASTM), 377
Anaerobically lubricated contacts, 1122–1123
Anaerobic vs. aerobic lubrication, 1121
Analog devices, arc motion measurements, 996–997
active or passive mode, 584
fall, 578
gain for gold contacts, 641
spot formation, 594
Anodic arc, 638
Anodic contact material, 638
Apparent contact, 1042
atmospheric pressure, 578
contact materials, See Arcing contact materials
and electrode interaction, 826
Elenbaas and Heller’s equation, 580
electron emission at cathode, 583
energy balance at cathode/anode, 581–585, 628–630
energy transfer at cathode/anode, 584
ferromagnetic attraction, 789
floating, 649
interruption, See Arc interruption
local thermodynamic equilibrium, 578
long-gap gas breakdown, 558–565
metal vapor in, 579
minimum arc current at initial contact parting, 585–588
minimum arc current, DC interruption, 606
motion, 596, 637, 759, 782–791, 800–802, 816–820, 992, 998
self induced magnetic fields, 999
parameters to sustain, 577
radius as f(current), 582
Saha’s equation, 579
short gap breakdown, 566
simulation of, 822–827, 839–840
squeezing and elongating of, 821
temperature of free burning, 579
time constant, 592
vacuum breakdown, 566
vacuum, See Vacuum arc
voltage characteristics, 762
voltage as f(contact gap), 589–591, 605
volt–ampere characteristics, 588–592
volt–current characteristics of separated contacts, 569–570
Arc behavior, 611
low-voltage circuit-breakers, 810–814
V-shaped runners, 787
Arc column, 578–581, 822, See also Arc
electron mobility, 579
electron temperature, 578
Elenbaas-Heller equation
arc boundary cooling effect, 581
high currents, 580
low currents, 580
thermal loses, 581
ionization potential, 561
ion mobility, 579
local thermodynamic equilibrium, 578
radiation loses, 581
Saha’s equation, 579
voltage as f(current), 588–592
Arc control in sliding contacts, 1133
Arc current, effect of, 631–633
Arc driven migration process, 1024, 1025, 1030
Arc duration
function of circuit inductance, 621
for gold contacts, 620
and residual current, 1061–1063
Arced tungsten–silver, 659–665, 930, 931
Arc erosion of electrical contacts, 628–630, See also Contact erosion
activated contacts, 1012
arc chamber material effect, 707
contact surface as result of arcing, See Contact surface as result of arcing
electric load effect, 994
in low-current AC circuits, 644–645, 770–773
in low-current DC circuits, 636–644, 766–770, 990–996
on make and erosion on break, 631, 995
measurement, 982
movement on contact surface, effect of, 1012
pip and crater formation, 638, 757, 899, 901–902, 980
radioactive tracer measurement of, 639–640
resistive loads, 979
silver-metal oxide contacts, 899–906
switching frequency effect, 993
W–Ag contacts and effect, 661, 662, 918–927
Arc Fault Circuit Interrupters (AFCIs), 850–853, See also Arcing faults
Arc fault, low current, 867, 868
during contact closing, 570–571
time lag, 571
during contact opening, 571–577
molten metal bridge formation, 571–577
molten metal bridge rupture, 573–577
pseudo arc, 576
metallic arc 577
Arc simulation
arc roots, cathode and anode, 824–825
Archard/Holm law, 1158
Archard’s adhesion model for wear, 271
Arcing contact
lubricants with refractory filler, 1030
silicone contamination of, See Silicone contamination, arcing contacts
Arcing contact design
arc-induced contact stresses and interface
brazed contact assembly designs, 966–969
clad metals, inlay, and edge lay, 969–970
contact alloys, See Contact alloys, non-arcing separable contacts
determination of contact size in AC operation, 635
staked contact assembly designs, 955–960
welded contact assembly designs, 960–966
Arcing contact materials, See also Contact materials, switching
manufacturing processes, 881
noble metals, See Noble metals
non-noble, See Non-noble silver alloys
silver cadmium oxide, See Silver metal oxide switching contacts
silver graphite contact materials, 939
silver metal oxides, See Silver metal oxide switching contacts
silver–nickel, See Silver nickel contact materials
silver refractory metals, See Silver-refractory metals
silver tin oxide, See Silver metal oxides
tungsten contacts, 689, 718, 936–937
vacuum interrupter materials, See Vacuum interrupter contact materials
Arcing faults, low current, 849–872
detection of, 872
other types, 871
Arcing region, 577
Arcing time, 642
in AC circuits, 618
activated contacts, 622–624, 1012
in DC circuits, 618–621, 624–628, 761–767
in very low current inductive circuits, See Showering arcs
Arc interactions, contaminants
contact materials, oxidation of, 1031–1032
long arcs, resistance effects, 1032–1034
organic contamination and activation, 1006–1014
refractory fillers, lubricants, 1030
silicone contamination, 665–667, 1018
Arc interruption, 597–612, 808, 836–837
in alternating current circuits, See Alternating current circuits, arc interruption in
in direct current circuits, See Direct current circuits, arc interruption in
of low frequency circuits, 609
of megahertz and gigahertz electronic circuits, 609–612
vacuum, in alternating circuits, 607–608, 836–838
Arc motion, measurement of, 586, 637, 759, 788–791, 816–820, 992, 996–999
Arc plasma, decay of, 602–603, 800–803, See also Arc interruption
Arc root
erosion at, 635
Arc, computer simulation of, low voltage circuit breakers and low voltage contactors
arc roots cathode and anode, 824–825
Arc splitting process, 825
Arc voltage characteristics, 633
Arc-wall interaction measurements, 999
Asperities
center line average, 421
elastic deformation, 253, 706–707
plastic deformation of, 13
work-hardening of, 16
a-spots, 4, 1111–1112, See also Constriction resistance, Contact resistance
boundary of, 1098
constriction resistance of, 6–23
electrical conduction in small, 79–83
Joule heat flow through, 82–83
micro-environment of, See Micro-environment of contact region
regular array of, 13
surrounded by oxide film, 55
temperature, 57
temperature distribution in, 63–64
voltage-temperature relation, See Voltage–temperature relation
ASTM, See American Society of Testing and Measurement
Asymmetric contact, temperature vs. voltage in, 1066
Atmospheric gases, 126–128, 144, 190, 1122
Atmospheric corrosion, 260–261
Atmospheric air particle concentration, function of temperature, 557
Atmospheric gas concentrations, outdoor and indoor environments, 126–128, 394–395
Atmospheric pressure, arc in air
arc volt–ampere characteristics, 588–592
minimum arc current and voltage, 585–588
Atomic force microscope (AFM), 712, 1115, 1141, 1157
Attractive magnetic-force curves, 678, 797
AuCuCd platings, 539
Audible bearing noise, 1087
Audible magnetic noise, 1087
Audible washer noise, 1087
Auger analysis, 130
Auger electron spectroscopy (AES), 693, 695
Automatic clamping, 327
Automobile applications, DC relays for, 636
Automotive brush applications
alternators, 1088
Automotive connector contacts, 405
Automotive electrical circuits, 621
Automotive electric power system, 1057
Automotive generator, 1070
Automotive position sensor connector, 402
Automotive sector, 733
Automotive systems, 765
Auxiliary motors, automotive, 1086–1088
Axial magnetic field, 596
B
Back-transfer prows, 421
cladding of, 246
contacts, 441
Bathtub life curve for connectors, 345
Belleville washers, See Disc-spring washers
BER, See Bit error rates
Bessel function, 20
B/F, See Branch feeder
B-fritting, See Fritting
Biasing spring, 354
Bimetallic system, galvanic corrosion in, 118, 263–264
Bi-metals in electrical contact, 64–65
maximum temperature plane in, 100–104
operation of, 96
Bismuth oxide, 894
Bit error rates (BER), 1139
Blade-leaf terminal, 387
Blow-off force, 646–650, 811–812
arc effect on, 649
minimum contact force to balance it, 647, 648
Blow-out field, magnetic, 788–792, 995
Bohr model of atom, 556
Boiling voltage vs. break voltage for metals, 575
Bolted connections, 236, 278–283
Boltzmann’s constant, 97
Bounce, See Contact bounce
Boundary lubrication, 488, 1107, 1120, 1173
Brass–indium interface, 36
Brass–tin interface, 37
Brass–zinc interface, 35
Brazed composite rivets, 959–960
Brazed contact assembly designs
direct and indirect resistance brazing, 967–968
toplay, 968
torch and induction brazing, 967
Breakaway friction force, 1102
Breakdown, See Long-gap gas breakdown; Short-gap breakdown; Vacuum breakdown
breakdown voltage, 563–568, See also Reignition voltage
Break-only contact pairs, 631
Bridge, molten metal, See Arc formation during contact opening; Molten metal bridge
erosion, 639
problem with, 723
Bridging contact, 637
Brinell hardness (BH), 1196
Brittle fracture, 426
Brittle interface, 41
Brittle materials, 915
Brush applications
aircraft and space brushes, 1090–1091
brush design, 1091
diesel electric locomotive, 1090
fractional horsepower motors, 1085–1086
instrument and control, 1093
minature motors, 1085
Brush configurations, See also Sliding contacts for instrument control
cantilever composite brush, 1128–1129
cantilever metallic finger, 1129
cantilever wire brush, 1129–1130
cartridge brush, 1128
multiple brushes, benefits of, 1130–1131
Brushes
design, 1091
multiple, benefits of, 1130–1131
solid lubricated composite materials for, 1133
Brush materials, 1073, 1082–1084, 1206
electro- and natural graphite, 1074–1075
Buckboost curve, 1082
Bump-flat terminal, 389
Bus-stab contacts, fretting effect on, 276–278
Butt contacts blow-off, 647–650
C
Cable termination, 381, 389–392
Capacitance, 1114
Capillary pressure, 1122
Carbon, 855
Carbon dioxide, 1125
Carbon-graphite brushes, 1083
Carbonized path clearing time test, 851–853
Carbon nanotubes (CNT), contact properties of, 714–716
Cartridge brush, 1128
Casimir force, 720
Cathode
arc, 638
brush, 1073
field emission, 567
gain for gold contacts, 641
T–F electron emission, 583
thermionic electron emission, 566, 583
Cathodic arc, 638
Cathodic contact material, 638
Cathodic polarization, 501
Cathodic protection, 261
Cathodic reduction method, 129
Center line average (CLA), 421
Chattering, contact, 657
Chemical oxidation reaction, 119
Chemical vapor deposition (CVD), 689
Chlorine, 117
in atmosphere, 537
Chrome–copper materials, 593, 836, 936, 1210
Circuit-breakers, See also Low-voltage circuit-breakers
high interrupting capacity designs, 806–815
medium-voltage vacuum, 828, 830–831
European type, 817
US type, 816
Circuit breaker terminal contacts, fretting in, 287–288
Circular contact spots, 1066
CLA, See Center line average
Clad contact assemblies, 969–970
Cladding, 246, 435–437, 520, 525
requirement, in contact terminal, 393
Clad palladium–gold–silver alloys, 458
Classical electrical contact theory, 5–17
in aluminum contacts, breakdown observations of, 84–87
electrical conduction in a-spots, 79–83
in gold contacts, breakdown observations of, 87
in small contact spots, breakdown of, 79
in tin contacts, breakdown observations of, 88–89
Clay-thickened greases, 503–504
Closed contact, 811
spring force on, 649
welding of, 651
Clusters, 1118
Coatings, See also Platings
of aluminum/copper, 331
power connectors, palliative measures, 331–333
properties related to porosity, 526–532
requirements of, 520
terminology, 521
Cobalt–gold coating, 485
Cobalt–gold electrodeposit, 429
Cobalt–gold electroplates, 422
Cobalt-hardened gold, variation of, 434
Co-deposited particulate material, 527
Coefficient of friction vs. ring temperature, 1053, 1054
Coil current distribution of dc motor, 1059
Coil reactance, 1082
Cold cathode, electron emission, 582, 583
Cold resistance of contact, 67
Cold-working, 651
Collisions electron with air, 555
Columnar vacuum arc, 595
Common galvanic cell, 118
Complex electro-mechanical assembly, 1139
Compliant pin connector, 380–381
Composite refractory materials, 928–935
Compression connectors, 274–275
Compression sleeve connector, 314–316, 344–345
Compression-type connectors, 313, 317
Conducting coatings, electrically, 23–28
Conductive plating, 253
Conductivity, effects on 237
deformation dislocations, 239
grain boundaries, 239
Hall effect, 240
lattice imperfections, 238
longitudinal magneto resistance, 239–240
magneto-resistance, 239
Matthiessens’ rule, 238
temperature, 238
vacancies, 239
Conductor materials
aluminum and aluminum alloys, 243–244
conductivity, 237
copper and copper alloys, 240–243
grain boundaries, 239
Hall effect, 240
imperfections, 238
longitudinal magneto resistance, 239
Matthiessen’s rule, 238
properties of, 237
skin effect, 240
temperature effect, 238
transverse vacancies, 239
Conductors
aluminum, See Aluminum conductors
copper, properties of, 241, 1198–1201
electric field between, 124
factors affecting conductivity, 237–240
solid metallic, classification of, 237
Connection resistance, constriction vs., 94–95
Connections, See also Connection systems, electrical
for high-vibration environment, 408
Connection systems, electrical
application parameters of, 376
contact, degradation of, 693
Connector contacts, fluid lubricants for, 491
Connector lock, 383
Connector position assurance (CPA), 383
Connectors
bolted joints, 361
contact, degradation of, 393
contacts, automotive, 405
dead-end, 327
degradation mechanism, 456
electronic, See Low power and electronic connectors
functional requirements, 377–378
high power for electric and hybrid vehicles, 405–406
low power, See Low power and electronic connectors
position sensor, 402
power, See Power connectors
stepped deep indentation, 315, 316, 344–345
Connector seal, 382
Connector systems, 237, 244–246
Consistent electrical contact resistance, 1102
Constant stiffness, 1102
Constriction resistance, 4–5, 57, 251, 543, 1055, 1107, See also a-spots; Contact resistance
vs. connection resistance, 94–95
elastic deformation, 14, 253, 706–707
for copper-copper contact, 82
non-circular and ring a-spots, 7–11
plastic deformation, 14, 239, 252
surface films effect on, 18–28
values of, 56
Contact activation, 622–624, 665–667, See also Activation of switching contacts
contact resistance problems, 1012–1014
definition, 1006
detecting carbon contamination, 1014
organic vapors, sources of, 1007
Contact ageing process, 350
Contact aid compounds, 332, 334–336
Contact alloys, non-arcing separable contacts
contact applications and performance, 972
manufacturing technology, 970
metallurgical properties, 971
physical and chemical properties, 970–971
Contact area, See also a-spots
effective, Hertz’s model for, 706
method to increase, 719
Contact asperity on constriction resistance, 17–18
Contact blow-off force, 646–650, 652
Contact bounce, 631, 720, 745–756, 980
arcing during bouncing, 631, 781
design parameters, for reduction of, 755
reduction of, 775
Contact chattering, 657
Contact cleaners, 622
Contact closing force, 15–16, 646, 652, 981
Contact closure, schematic diagrams of, 631, 773–778
Contact degradation, rate of, 472
Contact deterioration, economical consequences of, 346
Contact switching test devices, 876–978, 981–982
Contact dynamics, measurement of, 759, 996
Contact erosion, 633, 634, 641, See also Arc erosion of electrical contacts
in low-current AC circuits, 644–645, 770–773
in low-current DC circuits, 636–644, 766–770, 990–996
measurements, 755–761, 991, 993–996
Contact film resistance, 56, 251
Contact failures
electromechanical components, 189
preliminary attachment and final attachment, 223
single particle and ideal model, 222–223
Contact finishes, 539
contact resistance of, 543–544
hardness, 543
produced by non-chemical methods, 525
requirements, 520
Contact force, 15–16, 214–216, 313, 392, 404–405, 572, 743, 1097, 1098
Contact geometry (MEMS), 479
Contact impedance, 1096, 1112–1113
Contact inductance, 1112
Contact lubricants, See Lubricants
Contact material, switching
device testing and model switch testing, 976–978
Contact materials, switching, 742, 880–946, 954–972
dwell time of, 818
low-voltage contactors, 802–805
manufacturing processes, 884–890, 909–912
in MEMS, 713
switching in air, 791–793, 883–945
used in vacuum interrupters, 834–839, 1210
wear-out, 480
Contact metals, physical properties of, 1198–1205, 1209–1210
Contactors, See Low-voltage contactors
Contact over travel, 981
Contact region, 5–17, 249–250, See also a-spots, Contact area
Contact resistance (CR), 5, 384, 662, 882, 982–983, 1140, See also Constriction resistance, a-spots
activated contacts, 1012
in aluminum/aluminum contact, 46
arced tungsten–silver, 659–665, 930, 931
“a” spot temperature effect of, 703
behavior, 469
bolted joint configuration, 311–313
breakdown of classical theory, 84–89
characteristic, 259
composite refractory materials and, 928–935
and contact force, 719
contact load on, 14–17, 76, 77, 255, 313, 317, 318
dust effects, 212–214, 219–223
effects of fretting corrosion, 457
electrical conduction in small a-spots, 79–83
and electrical erosion vs. switching current level, 929
electrically conducting films on, 23–28
electrically weakly conducting and insulating films, 45–57
evaluation and presentation of results, 985–986
gold probe, 983
intermetallic layer growth on, 28–45, 464
low energy and higher energy arcs, 1013
magnitude, 7
measurement, 27, 130–131, 364, 982
organic gas, 1014
oxide layers, 932
between powder grains, 821
of pure gold platings, 537
plating factor, 25
rate of rise of, 533
silicone effect of, 665–667, 1018–1030
silver metal oxides, 907
silver refractory metal systems, 934–935
stability, categorization of, 449
static vs., dynamic, 445
surface films effect on, 18, 45, 50, 53, 657–665
vs. switching current level, 819, 928
vs. switching current duration, 1032
temperature development, See Voltage–temperature relation
thermal stability of, 534, 535
thin films and spreading resistance, 18
of tin on various substrates, 540
tungsten compounds, properties of, 929, 930
variation (noise), 1108–1109, 1138
Contact rivets
brazed composite rivets, 959–960
composite, 956
machine-made composite rivets, 956–959
rivet staking, 960
squeeze test, 958
ultra-sonic testing, 959
Contacts
arc dwell time on, 789–790, 818
bounce, measurement, 777–781, 986–989
carrier mass and conductivity, 981
at current levels, 742
mechanical area of, 14
nominal/true area of, 13
size in AC operation, 635
switching device simulations, 827
Contact spots, See a-spots
Contacts switching, 618–628, 636–644, 674–725, 703–725, 733–781, 787–839, 890–898, 918–934
Contact super-temperature, 59
Contact surfaces, measurement of, 756–757
Contact surface as result of arcing, 657–665, 906, 930–934, See also Arc erosion of electrical contacts
ambient effects on, 665–667, 1006–1034
silver-based contacts, 659, 889–900
silver refractory metal contacts, 659–665, 930–934
Contact welding, See also Welding
during contact closure, 654–657, 774, 902
as contacts open, 657
on make operation, 654–657, 774–775, 902–903
Contactor-air, See Low-voltage contactors
Control motors, 1085
Conventional catalysis reactions, poisons for, 459
Conventional d.c. generator, 1088
Conversion table for; Imperial, cgs and SI units, 1208
Coordinated Switching and Protective devices (CPS), 814
Copper
coating of, 331
degradation of, 128
diffusion rates, 532
electrolytic refining of, 240
intermetallics on, 539
metallographic sections of gold plated on, 530
stress relaxation of, 303
Copper-based carrier alloy materials, 1205
Copper-based spring alloy materials, 1205
Copper conductors, properties of, 241
Copper–copper contacts, 469
Copper–copper power connections, 133
Copper–copper systems, 462
Copper–graphite contacts, 943, 1202
Copper oxide
additions, 894
fritting of, 1057
growth rate and electrical resistivity, 47–49, 54, 141
Copper refractory metals
high erosion rate, 925
low erosion rate, 926
tungsten–copper composite contacts, 922–923, 1205
Copper rods, copper oxide on, 1058
Copper-to-copper wire glowing connections, 859–860
Copper–tungsten materials, 922–927, 1205
Corrosion, 114–134, 140–151, 260–263, 383–405
atmospheric environment, 126–128, 143–144
contacts under mineral oil, 125–126
creep, 122–123, 154–157, 262–263
crevice, 261
dust, 134–135, 205–211, 263, See also Dust contamination
electrolytic, 404
electro-migration, 123
temperature effect, 124
electronic connectors, 131–133
environment factors, 144
film, kinetic growth of, 116
fretting, 282, 283, See also Fretting
galvanic, 118–120, 263–264, 394, 404, 407
inhibitors, 179
laboratory gas effects on, 128, 159, 160
localized, 261
lubrication and inhibition of, 174–180
metallic electromigration, 123–124
mineral oil effect of, 125–126
nickel, 152
pitting, 262
pore, 120–122, 153, 262, 527–532, See also Porosity
pore corrosion product, 114
porous gold, 153
properties, 1134
protection, 179
reactivity distributions, 148–151
silver, 151
stress corrosion cracking, 124–125
thermal expansion, 264
tin, 152
vibration effect of, 180
visual inspection, 129
Corrosion inhibition, See Lubrication
Corrosion rates, 114–116, 145–181
other metals, 145
oxide growth rate and electrical resistivity, 47–56
reactivity distribution, 148–149
Corrosion stains, dust contamination
corrosion products vs. dust, 209
structure of, 208
thin gold-plated surface, 206, 207
Corrosive gases, single, 117, 159–164
Corrosive gases, mixed flowing, 167–171
humidity, 117–118, 124, 127, 144, 164
Coulomb’s law of friction, 1048
Counterface, sliding contacts
CPA, See Connector position assurance
CP-AFM technique, 272
CPS, See Coordinated Switching and Protective devices
CR, See Contact resistance
Crater erosion, See Pip and crater formation
Creep, metal, 299, 305–306, 1100
logarithmic law, 305
stress relaxation vs., 299–300
Crimped connections, 274, 315, 390–392
Critical vacuum breakdown field for metals, 568
Crossed-rod contact, 1126
Crossed rod contact resistance measurement, 130–131, 983
Crystal structure, graphite, 1075
CSA, Canadian Standards Association, 794, 806
CTF, See Cycles to failure
Cumulative contact resistance, 984
Cumulative probability, 652–653, 984
Cumulative weld strength, 653
Cu radiation, 576
Current-cycling tests for fixed connections
Current distribution in parallel contacts, 650, 813–814
Current-induced diffusion, See Intermetallics
Current limiting
in a.c. circuits, principle of, 608–609, 808, 809
breakers, 812
other techniques, 821
contact resistance between powder grains, 821
liquid or low-melting metals, 821
narrow insulating slots, 821
reversible phase change materials, 821
temperature-dependent ceramics or polymers, 821
CVD, See Chemical vapor deposition
Cyanide nickel-hardened gold plates, polymers in, 422
Cycles to failure (CTF), 401, See also Fretting
D
“Dark discharge,” 563
DC circuit, See Direct current arcs, Direct current circuit, arc interruption in
DC motor driving automotive fuel pump, 1061
DC testing vs. AC testing, 978–979
Dead-end connectors, 327
Debris-filled interface, 447, See also Fretting
Debris generation, rate of, 415, See also Fretting
of connector sleeve, 314
plastic, 13, 75–79, 239, 252, 1161–1163
Delamination wear, 480, See also Wear
mechanism of, 271
DEP, See Diethylphthalate
Design of Experiment (DOE) approach, 977
Device testing, 976
definition, 526
Dielectric reignition, arc plasma decay of, 602–603
Diesel electric locomotive brushes, 1090
Diethylphthalate (DEP), 1010
Differential electrochemical cell, 118
Diffused gold 60Pd40Ag, 521
Digital devices, arc motion measurements, 759, 997
Digital signal processors (DSP), 1139
Diode-rectified generator, 1088
Direct current arcs, 604, 618, 761
current erosion, 766–768, See also Arc erosion
direct current operation, 780
opening speed and arc length, 764–765
quasi-static conditions, Ag/CdO contacts, 763–764
Direct current (DC) circuit arc interruption in, 604–607, 637, 820
arc plasma and dielectric reignition, decay of, 602–603
effect of current level, 599, 800
instantaneous dielectric recovery, 600–607
minimum arc current at interruption, 606
restrike, 637
self extinction, 788
stages, 607
voltage generation, 604, 618, 820
Discontinuous erosion, 632, 633
Disc-spring washers, 322–325, 329–331
Dissociation process, 559
DOE approach, See Design of Experiment approach
Double-break arrangements, contactors, 796
Double-break contact systems, 637, 799
Dry tin-plated connection, systematic studies of, 280, See also Fretting
DSP, See Digital signal processors
atmospheric environment, 143–144
chemical behavior, 205
collection and shape, 191
composition, 191–193
contact failure mechanism, 222–223
contact interface, 219
corrosion mechanisms, 151–157, 263
corrosion products, trapping effect of, 221, 222
corrosion stain, 208
deposition, 187
dust shield, 135
dusty water solutions, 205–206
electrical behavior
electric charge, measurement of, 193–194
electrostatic attracting force, 195–198
elements atomic percentage vs. accelerating voltage, 216, 217
fretting, 204
fritting, 204
high and erratic contact resistance, 212–213
indoor exposure results, 206–208
mechanical behavior, See Mechanical behavior micro motion, 211–212, 223–224
organic and inorganic materials, 192
SEM/XES, 216
short life vs. longer life contacts, 218
source, 190
stress corrosion cracking, 125
test systems, 189
Dwell time of arc on contacts, 789–790, 818
Dynamic blow-off, closed contacts, 646–650, 812
Dynamic welding, 654–657, 774, 903, 904, 989
E
Edge-on type connector, 379–380
EDX, See Energy dispersive X-ray
EIA, See Electronics Industries Association
Elastic contact, 253, 702–707, 1161–1163, 1182–1184
Elastic deformation, 14, 253, 706–707
Elastic electron-gas collisions, 559
Electrical breakdown of gases, See Long-gap gas breakdown
Electrical constriction resistance, See Constriction resistance
Electrical current
Electrical interface, See a-spots; Constriction resistance; Contact resistance; Corrosion; Fretting; Fritting; Intermetallics
Electrically conductive coatings, 18–28, 253, See also Spreading resistance
Electrically conductive layers
on conducting substrate, 22–23
on insulated substrate, 18
and thin contaminant films, 23–28
Electrically insulating films, 45–57
Electrical measurement methods
AC arc reignition measurement, 996, See also Alternating circuit currents, arc interruption in
arc motion measurements, 996–999
arc-wall interaction measurements, 999
contact erosion, 756–761, 991–996
contact resistance, 130, 982–985
Electrical performance in sliding contacts, 1107–1108, See also Sliding contacts for instrument control
Electrical resistivity, 6–26, 1200
of metals and Wiedemann–Franz Law, 96–100
at room temperature, 82
temperature coefficients of, 1200
Electrical safety, 849
Electric arc, 578–596, See also Arc
Electric arc formation, See Arc formation
Electric field, definition of, 558
Electrode materials, low current arcing fault properties, 866, 867
contact resistance trends and, 533
hard golds, 422
microthrowing characteristics of, 545
Electrographite brushes, 1048, 1056, 1074–1075, 1206
Electrographitic brush materials, 1082–1083
Electroless gold plating, 423
Electroless Nickel and Immersion Gold (ENIG) plating, 423, 522
Electroless nickel–phosphorus, 423
Electrolytically tough pitch (ETP) copper, 240
Electrolytic refining of copper, 240
Electromagnetic penetration depth, 90
Electromigration, 295–296, 639
on intermetallic growth rates, possible effect, 42–45
Electron avalanche, 561
Electron ballistic motion of, 80, 708
Electron bombardment, 640, See also Arc erosion
Electron-dislocation interaction, See Stress relaxation
Electron emission, 566–570, 583, 603
energy for at arc cathode, 583
Fowler-Nordheim rquation, 567
potential energy near contact surface, 566–567
Richardson-Dushman equation, 566
thermally enhanced field emission (T-F), 583
Electron-gas collisions, 569
dissociation, 559
elastic, 559
excitation and relaxation, 559
ionization, 560
Electron mean free path in air, 559, 562
Electronic connectors, 114, 131–133, 171–172, 378–381, 388–389
contact platings in, 522
finishes, 522
Electronic mean free path in metals, 82
Electronic optical devices, 996–997
Electronics Industries Association (EIA), 377
Electronic/switching systems, integration with, 805–806, 849–872
Electronic thermal overload trip solutions, 814–815
Electron mean free path in air, 558–559
Electron microprobe, 130
Electron probe microanalysis (EPMA), 690
Electron spectroscopy for chemical analysis (ESCA), 130, 1033
Electron theory of metals, 96, 238
Electroplastic effect, 301, 302
Electroplated palladium–nickel alloy, 458
Electroplating, 226, 244–246, 249, 253–256, 422–423, 522–526
intrinsic polymers in hard gold, 422
Electropolymerization, 458, 462
Electrostatic actuation (MEMS), 704
Electrostatic micro-switch, 704
Elenbaas–Heller equation, 581
Energy balance from arc at contacts, 581–585, 628–630
Energy dispersive X-ray (EDX), 464, 1026
Energy transfer at arc cathode/anode, possible mechanism of, 584
ENIG plating, See Electroless Nickel and Immersion Gold plating
Environmental classes, reactivity distributions, 150
EPMA, See Electron probe microanalysis
Erosion of contacts, See Arc erosion of electrical contacts; Contact erosion
ESCA, See Electron spectroscopy for chemical analysis
European miniature circuit-breakers, 816, 817
F
Fabrication characteristics of metal plates, 526
Failed mobile phones, performance of, 218
Fermi–Dirac distribution function, 97–98
Ferromagnetic materials, conduction in, 240
Fiber brushes, See Metal fiber brushes Field emission, 566–568
Field environments for electrical contacts, 143–157
Film resistance, 56, 251, 1055–1056
Film rupture, 255, See also Fretting; Fritting
Film thickness, growth of silicones, 665–666
Filtered connectors, 383
Fine transfer, 723, 724, See also Molten metal bridge
Finite element analysis, 13, 1044
Finite Element Method (FEM), 91, 711, 722, 823
Finite Volume (FVM) software, 823
“Fire” curve, 853
Fixed contact gap test devices, 994
Flash coatings, effect on porosity, 530–531
Flash gold coating, 174
Flash gold plating, 131, 486, 522
Flattening of rough surface, 79
Flexible printed circuit (FPC), 388
Floating arc, 649
Flowing mixed gas (FMG) environment, 132, 167–171
Fluid contact lubrication, 1173
Fluid lubricants, See Lubricants
FMG environment, See Flowing mixed gas environment
Foam metals, 361
Force–displacement friction curve, 444
Formative time lag, gas breakdown, 571
Four-gas tests, 168
Four states of matter, 554
Fowler-Nordheim equation, 567
FPC, See Flexible printed circuit
Fractal model for rough surfaces, 79
Fractional horsepower motors, 1085–1086
Free-burning arc column, 579–582, 588–592
Frequency, low current arcing fault properties, 865–866
Fretting, 134, 267, 398–402, 414, 441–482, 722
apparatus, materials studies, 449–450
bus-stab contacts, 276–278, 287
in circuit breaker terminals, 287–288
compression connectors, 274–275
current effect of, 476
cycles to failure (CTF), 401
degradation, control of, 496–500
dust effect, 204
electrical current effect, 285–286, 476–479
environmental effects, 474–475
examples, 274
field and laboratory testing methodologies, 447–449
frictional polymer-forming metals, 457–460
gross slip, 444
lubrication effect of, 179–180, 496–500
maps, 445
material transfer, wear, film formation, and contact resistance, 479–481
mating contacts, dissimilar metals on, 460–464
mechanisms of, 270–274, 447–449
mixed slip, 444
no film-forming tendency, 450–452
non-noble metals/fretting corrosion, 452–457
oxide debris, 271
partial slip, 443
plug-in connectors, 278
power connection, 274
static vs. dynamic contact resistance, 445–447
sticking, 442
surface finish and contact geometry, 479
Type I (Unstable) contact resistance behavior, 449–452
Type II (Intermediate) contact resistance behavior, 449–452
Type III (Stable) contact resistance behavior, 449–452
underplate effect of, 467
Fretting corrosion, 282, 283, 396–398, 401–402, 445, 452–457
debris filled interface, 447
material studies
aluminum vs. aluminum, 283–285, 456
copper vs. copper, 452
gold vs. copper, 464
gold vs. nickel, 462
gold vs. tin/lead, 180, 463, 456
identical base metals, 456, 479
identical non film forming metals, 479
mono-metallic interfaces, 456
silver and silver alloys, 282–283, 450, 461
palladium and palladium alloys, 458, 461
tin and tin alloys, 179, 280, 283–285, 396–402, 453, 466
oxide debris, 271
substrate effect of, 467
of surface, 1124
adhesion theory of, 481
force displacement curve, 444
Frictional polymer-forming metals, 457–460, 480
Frictional polymerization, 487
Frictional polymers, 23, 149, 447, 458, 1124
conventional catalysis reactions, poisons for, 459
effects of, 480
formation rates, 471
yield, 469
Friction welding, 339–340, 966
Fuel injector connector, 403
Furnace brazing, 968
Fusion coatings, 522
G
Galling, 1103
Galvanic corrosion, 118–120, 263–264, 404, 407
Galvanic series, 120
Gas breakdown, See Long-gap gas breakdown
Gas chromatography/mass spectrometry (GC/MS), 192
Gas concentrations in atmosphere, 126–128
Gas corrosion, See also Corrosion
field environments for electrical contacts, See Field environments for electrical contacts; Atmospheric gas concentrations
laboratory accelerated testing, See Laboratory accelerated testing, corrosion
Gas exposure tests, 528
Gas flow effects, single-gas corrosion, 165–168
Gas, molecular mean free path in air, 562
Gas 3rd form of matter, 554
Generators, 1089
Gigahertz electronic circuits, interruption of, 609–612
Glassy silicon-rich deposits, 1024–1025
Glow discharge, 570
Glowing connections
copper-to-copper wire, 403, 859–860
current and voltage waveforms, 861–863
floating arc, 649
Glowing contacts, 403–404, 857
Glow voltage, 565, 570, 860–861
degradation of, 128
and gold alloy contacts, 714
Gold alloys, 521, 970, 1134, 1204, See also Hard golds
arc duration for, 620
classical electrical contact theory in, 87
Gold fiber brush resistances, speed dependence of, 1180
Gold-flashed palladium, 480, 487, 546
Gold-plated connectors, 532
Gold-plated contacts, 245, 431, 435, 523
Gold-plated copper system, 535
Gold-plated film on copper, 123
Gold plating process, 1115
Grafted lubricant layers, 500–503
Granular interface model, 447
Graphite, 1125, See also Activation of switching contacts
atoms, layered structure of, 1074–1075
thermionic emission for, 855, 856
Graphite-lubricated sliding contacts, 1053
Graphitization, 1083
Growth wear model, 1048
Guillotine test, 854
H
Hall Effect, 240
Halogen-containing fluid, 495
Hard ductile underplates, 431
Hardener content of gold plates, 432–435
Hard golds, 523
adverse effect of nickel underplate for, 537
fabrication characteristics of, 526
intrinsic polymers in, 525
Hard mount method, 1178
Brinnel, 1196
material, 713
Mohs (dusts), 199
Rockwell, 1196
and tensile strength, 651
Vickers, 1196
Hard nickel underplate, beneficial role of, 428
Harmonic distortion, power quality issues, 348
Heavy-duty connectors, See Power connectors
HF transients, See High frequency transients
High current arc, 581
High-current vacuum arc, 595, 596
High frequency current circuits
interruption of, 609
solid state vs. mechanical switches, 610
High frequency (HF) transients, interruption of, 837–838
High-speed cinematography, 996
High-temperature lubrication limits, 1124
High voltage interlock circuit (HVIL), 406
Holm-Archard wear law, 415, 1048, 1158
Holm graphical method, 761
Holm’s wear equation, 1071, 1072
Hot-dip tinning process, 298
Hot wax dip, 261
Humidity, 117–118, 124, 127, 144, 164
water vapor in saturated air, 1209
HVIL, See High voltage interlock circuit
Hybrid contactors, 805
Hydrogen sulfide, 117–118, 127, 142, 159, 161–162
Hysteresis, 705
I
IACS, International annealed copper Standard, 241
IDC, See Insulation displacement connection
IEC, See International Electrotechnical Commission
IMCs, See Intermetallic compounds
Indium oxide, See also Silver metal oxide switching contacts
PM and IO materials, 893
PM silver–tin oxide material, 894
Indoor industrial environments, 126, 128
Induction brazing, 967
Inductive-coupled plasma (ICP) spectrometer, 192
Industrial brushes, 1089–1090, 1152
Inelastic electron collisions, 559
Instantaneous dielectric recovery, 600–602, 799–801, See also Arc interruption
Insulation displacement connection (IDC), 381–382, 386
Insulation piercing connectors, 236, 382
Intentional contamination, 1119–1121
Inter-contact plasma, initial rapid adjustment of, 601, 607
Interdiffusion bands, growth of, 38
Interdiffusion in electrical interfaces, 41
Intermediate displacement amplitudes, 444
Intermetallic compounds (IMCs), 32, 288–298, 532, 539–541
in Al-Au systems, 132
in Al-brass systems, 29–33, 39, 44
in In-brass systems, 32, 36, 37, 38
in In-bronze systems, 32, 37, 38
in Ni-Sn systems, 540
in Sn-brass systems, 32, 37, 38, 405
in Sn-Cu systems, 32, 296–299, 438, 540
in Sn-bronze systems, 32, 37, 38
in Zn-brass systems, 32, 35, 38
in Zn-bronze systems, 32, 37, 38
diffusion process, 28–45, 288–292
establishment and growth of, 290
failure examples, 298
formation of, 476
Intermetallic layers growth, 28
current induced diffusion, 295
temperature, 33
International Electrotechnical Commission (IEC), 315
International Standards Organization (ISO), 377
Interruption, power quality issues, 348
Intrinsic polymers
degradation of, 532
in hard gold plates, 525
Intrinsic porosity in electrodeposited coatings, 527
Ion chromatographic (IC) spectrometer, 192
Ion mean free path in air, 562
Ionization energy, 560
Ionization potential, values of, 561
Ionization process, 556, 559–560
Iridium, 689
J
Joule heat, 18, 43, 57, 280, 1166–1167
effects, 1112
K
Key switch, 698
Kinetic energy of molecules, 555, 556–577
Kinetic gas theory, 555, 556–577
Kinetic growth of corrosion film, 116
Kirkendall porosity, 532
Knoop hardness (KH), 341, 1196
Knoop microhardness of intermetallic layer, 34
Knudsen number, 1111
Kohlrausch–Holm Method, 1065–1066
L
Laboratory accelerated testing, corrosion
mixed-gas environments, 167–171
Lamp loads, effects from operation parameters, 890, 979
Laplace’s equation, 7
Laser microscopy analysis, 1044
Laser vibrometer measurements, 1136
Lattice imperfections, effect of, 238–239
Layered systems, characteristics of, 543–544
Lever switches, 737
Life test of contactors, conditions for, 795
Light-duty connectors, 235
Linear momentum, conservation of, 749
Linear tarnish kinetic equation, 115, 1197
Line insulation, 381
Liquid 2nd state of matter, 554
Load-bearing areas, 14, 249–250, 705–707, 1097, 1098, 1106
Local thermodynamic equilibrium, 578
Logarithmic tarnish kinetic equation, 115
Long duration arcs, effect on contact resistance, 906–908, 1032
ESCA analysis, 1033
metallic and gaseous arcs, 1033–1034
switching tests, 1032
Long-gap gas breakdown, 558–565
dissociation, 559
excitation and relaxation, 559
ionization, 559
Paschen’s law, 564
time lag, 571
Townsend avalanche, 561
Longitudinal magneto resistance, 240
Low contact force, 79, 404–405, 705–707
Low-current switching devices, 733–734, See also Switches, low current
Low ductility, 1134
Low frequency power circuits, interruption of, 609
Low power and electronic connectors
applications, 376
connector position assurance (CPA), 379, 393
compliant pin, 380
crimp terminals, 390
edge-on, 379
eye of needle, 380
flexible printed circuits (FPC), 380
insulation displacement (IDC), 382, 386
lug-screw, 385
materials, 385
pin-hyperloid, 388
pin-socket, 417
plug and receptical, 379
rack and panel, 378
terminal position assurance (TPA), 379, 383
terminal temperature, 393
terminal bulk resistance, 393
terminal-terminal, 378
wire-screw, 385
zero insertion force (ZIF), 383
Low-pressure, vacuum operation, 1125
Low surface tension lubricant, 1122
Low-temperature lubrication limits, 1124
Low-voltage circuit-breakers, See also Molded-case circuit-breakers; Miniature circuit-breakers
arc chute and contact arrangement, 787–788, 810–814
arc sticking and back commutation, 637, 790–791
contact materials, 791–793, 815–820
current limitation, deion arc chutes, 608–609, 820–822
electronic control, 814
principle/requirements, 806–807
Low-voltage contactors, 792–806
air, 794
bus system integration, 806
electronic control of magnet, 806
mechanical arrangement, 794, 796–798
pneumatic, 794
principle/requirements, 794, 795
quenching principle and contact and arc chute design, 798–802
relays, 802
testing: AC-1,-2, -3 & -4, 794–795
vacuum, 805
Low-voltage switching devices computer simulation, 822–827
fretting on, 179–180, 204–205, 487, 496–500
fundamental properties of, 488–491
halogen containing fluids, 495
liquid, grease and wax lubricants, 175–177, 203–204, 334–336, 488–496, 503–505
lubricants coated, 175, 201–203
requirements, 177–178, 491–492
role of, 442
Lubrication, 134, 174–180, 334–336, 481–506, 1119
aerobic, 1141
contact aid compounds, 175–176, 334–336
contact resistance effect on, 175–177
grafted and self-assembled lubricant layers, 500–503
lubricant durability, 177, 504–505
particle displacement, 201–204, 505–506
sliding contacts, 1121–1125, 1172–1173
studies, 179
vapor, 1125
M
Machine-made composite rivets
ultrasonic methods, 959
brush configurations, See Brush configurations
counterface configuration, 1126–1127
real vs. apparent area of contact, 1128
Magnet coils, electronic control of, 806
Magnet drive characteristics of reed switch, 683–686
Magnetic devices, arc motion measurements, 997
Magnetic driven reed switches, applications of, 698–701
Magnetic fields
of coil, 674
Make-and-break erosion, 631, 995
Make-and-break test, of contactors, 795
Martensitic transformation, 351–352
Mass transfer, between contacts, 636–644, 757, 766–768, 899
Mated exposures, vs. unmated, 172–174
Matthiessen’s rule, 238
Maxwell–Boltzmann distribution function, 556
Maxwell (continuum) vs. Sharvin (ballistic) resistance, 1110
MCCB, See Molded-case circuit-breakers
MD simulations, See Molecular dynamics simulations
Mean free paths of molecules, electrons and ions in air, 562
Mechanical behavior
fretting, See Fretting
lubricants, See Lubricants
sliding contacts, 201
wax and liquid lubricants, 203–204
“Mechanochemical reaction,” 460
Medium-duty connectors, See Low power and electronic connectors
Medium-sized motors, 1089
Megahertz electronic circuits, interruption of, 609–612
Melting voltage, 60, 61, 89, 95–96, 562, 1198
MEMS, See Microelectromechanical systems
Metal conductor classifications, 237
Metal dendrites, growth of, 124, 125
Metal fiber brushes, 1152–1181, See also Sliding wear, of multifiber brushes
applications, diversification of, 1154–1156
brush construction, electrical resistance, 1174–1177
clean metal fiber brushes, 1170
electrical resistance on construction, 1174–1177
elements of, 1154
fiber brush designs, 1152, 1153
film disruption, 1172
flash temperatures, 1166
estimating, 1169
pertinent mathematical theory of, 1167
future directions for, 1180–1181
kinetic tarnish equation, 1197
Kuhlmann-Wilsdorf tests, 1154
non-tarnishing metals, 1172
materials, 1157
metal coated, 1076
pertinent mathematical theory of flash temperatures, 1167
plastic and elastic contact, 1161–1163
resin-bonded brush materials, 1083–1084
sliding wear, multi-fiber brushes, See sliding wear, of multi-fiber brushes
sliding speed of, 1180
spring model for fiber brush, 1178–1179
steady state flash temperature, 1169
surface films, friction, and materials properties, 1170–1173
thin film behavior, 1170
water surface films, 1170–1172
Metal foam, materials of, 355–361
Metal-in-elastomer materials, 525–526
Metallic a-spots, 56
Metallic electromigration, 123–125
Metallic film lubrication, principles of, 481–482, 485
Metallic finishes, coatings on, 520
electrodeposits and electroless deposits, 522–525
metal-in-elastomer materials, 525–526
overview, 526
Metallic phase arc, 642–643, 762–763
Metallographic methods, 912–918
Metallurgical methods, 912–918
Metals
boiling voltage vs. break voltage for, 575
in contact with non-metal, 65
critical vacuum breakdown field for, 568
electrical resistivity and thermal conductivity, 96–100
fabrication characteristics of, 526
melting voltages for, 573, 1198
properties at melting point, 1209
Metal–semiconductor contacts, 22
Metal-to-metal a-spots, 69
Metal-to-metal contact, 27, 55, 118
Metal transfer, See Arc erosion
Methods B735, B741B799, B809 (ASTM), 528
MFG, See Mixed flowing gas
Micro-contact resistance modeling, 705–713
contact resistance in, See Contact resistance
spreading resistance in, 709
Microcrystalline wax, 504
Microelectromechanical systems (MEMS), 77, 610, 703–725, 1113
contact materials for performance and reliability, 713–720
failure modes and reliability, 720
micro-contact resistance modeling, See Micro-contact resistance modeling
Micro-environment of contact region, 1114–1115
Micro sliding, 1100
Microtopography
evolution of, 79
of surfaces, 7
MIL Specs, Military Specifications, 179, 377
Minature motors, brushes for, 1085
Mindlin model, 273
Mineral oil, contacts under, 125–126
Mineral particles, arcing contact, 1015–1018
Mineral particulate contamination, arcing contacts
contaminant type, 1017
SiC-contaminated materials, 1015–1016
Miniature circuit-breakers, 815–816, See also Low-voltage circuit-breakers
dwell time, 818
examples, 815
Miscellaneous conversion table, 1208
Mixed-gas sulfur environments, 164
Mixed slip, 444
Model test switch arc motion control, 998–999
Model test switch testing, 977–978
contact erosion, 993
Moisture, 124
Molded-case circuit-breakers (MCCB), 807–809, See also Low voltage circuit breakers
MOLE, See Molecular optical laser examiner
Molecular attrition, 270
Molecular dynamics (MD) simulations, 490, 718, 1103
Molecular optical laser examiner (MOLE), 693, 695
Molecular re-ordering in polymeric films, 1100
Molten metal bridge, 572–577, 619, See also Arc formation during contact opening
break/rupture voltage, 575–576
for Cu–Cr contacts opening, 593
erosion
Buhl effect, 639
electro migration, 639
Kohler effect, 639
Thompson effect, 639
voltage characteristics of, 573
Molybdenum disulfide, 1125, 1133
Monte Carlo techniques, 13
Motion continuation, 1102
Motion initiation (pre-sliding), 1100
Motion of high current columnar vacuum arc, 596
Motor control, 806
Motor Protection Circuit Breakers (MPCB), 814
Moving-contact dynamics, 745–747
Moving contact test devices, 994–995
MPCB, See Motor Protection Circuit Breakers
Multi-fiber brushes, sliding wear of, See Sliding wear, of multi-fiber brushes
Multifilament brush, 1130, 1131
Multilam contact elements, 338–339
Multiple exposed still photographs technique, 996
Multiple-wafer brushes, 1090
Multiscale model for rough surfaces, 79
Multiwall carbon nanotubes (MWNTs), 715
N
Natural graphite, 1075
NEC, National Electric Code, 377
NEMA, National Electrical Manufacturers Association, 794
Net cathode gain for gold contacts, 641
vs. copper contacts, 452
corrosion mechanisms, 152
degradation of, 128
Nickel–aluminum system melting voltage, 67, 68
Nickel-hardened gold, 427
Nickel nano-wires, 719
Nickel–nickel systems, 462
growth rate and electrical resistivity, 51–52, 54
thickness, 523
adverse effect of, 537
gold-flashed palladium on, 546
noble metal layer on, 532
Nitrogen dioxide (NO2), 117, 163
Nitrogen ion, acceleration of, 558
palladium and silver–palladium alloys, 940–942
in sliding contacts, 1132
Nodular plating finish, 546
No film-forming tendency, 450–452
Nominal plating thicknesses, 523
Non-catalytic elements, 459
Non-chemical methods, contact finishes produced by, 525
Non-contact surface profiling systems, 758
Non-corrosive film formation, 493
Non-metal, metal in contact with, 65
Non-noble metals, 240–245, 415, 437, 452–457, 524–525
hard silver and silver–copper alloys, 938
Non-ohmic “tunneling” conductance, 1107
Nut factor, 319
O
OFHC, See Oxygen-free high-conductivity copper
Oleic acid, lubrication with, 177
Optical devices, arc motion measurements, 759, 996
Organic contamination and activation, See Activation; Contact activation
Outdoor industrial environments, 126
Oxidation, 117, 118, 151–152, 256–260, 1051, 1052
Oxidation-inhibiting additives, 492
Oxide debris, See Fretting corrosion
Oxide films, 47–57, 140–143, 256–260
Oxide-free aluminum surface, 69, 70
Oxides of contact materials, growth rate and electrical resistivity, 47–56
Oxidizing gas, 117
Oxygen-free high-conductivity copper (OFHC), 241, 434–436
Ozone, 117