3.1.1. What are the basic qualities of a mechanical engineer?

The engineering community is involved in many industries and has had great influence on their development, with mechanical engineers being an important part of it. With the rapid development of modern science and technology and society, the boundaries between many disciplines are becoming less obvious. The intersection of marginal disciplines and interdisciplinarity has become widespread. For a mechanical engineer, the most basic ability is to acquire more knowledge and develop a tight knowledge structure.

As mechanical engineers are involved in a wide range of fields and engaged in many jobs, their basic qualities are more comprehensive. Mechanical engineers should have a strong and solid foundation of knowledge to enhance adaptability for future work; a solid theoretical knowledge of the profession and technical practical skills to enhance professional research and development capabilities; a passion for science to enhance research and continuous innovation ability; the broad knowledge of economic management and technical management to enhance the ability to process and solve engineering problems; abundant knowledge of sociology to enhance the integration of development, science technology and social interaction [LI 00].

3.1.2. How to achieve sustainable development of mechanical engineers

Figure 3.1 depicts a sustainable development process of mechanical engineers. First of all, mechanical engineers need to improve their basic skills, solve basic work problems, and continue to learn on the job, accumulate knowledge and improve themselves constantly. At the same time, engineers need to communicate with each other, exchange work experiences, discuss cutting-edge technology, expand their horizons, and build a good communication environment. Finally, the development of the next generation of engineers should focus on developing the fundamental skills of the future, describing the experience of problem-solving and looking at the big picture. A cradle for training the engineers should be formed. Sustainable development is a long-term strategic goal which requires the common struggle of human generations. Therefore, mechanical engineers should think from a long-term perspective, in order that successive generations of engineers will be more advanced. Engineering technology can continue and, ultimately, serve society and benefit the people of the future.

3.1.3. The relationship between the sustainable development of mechanical engineers and the sustainable development of society

Society is like a ship that sails far away, and mechanical engineers are like sailors on the ship, and only if the sailors are skilled enough will the ship be able to sail safely across the ocean. In the process, sailors can also see the vastness and the beautiful scenery of the sea, thus accumulating more experience in navigation, and improving their sailing skills constantly.

As shown in Figure 3.1, if mechanical engineers continue to innovate and promote science and technology, society will progress and evolve accordingly. However, factors affecting the development of society are not single, and as it continues to evolve under the influence of other factors, it can provide a better environment for research, better material needs, and better scientific power. Mechanical engineers can accelerate their pace and make progress for society, which also promotes the development of mechanical engineers accordingly, and improving their knowledge to keep pace with the times. It can be concluded that the progress of mechanical engineers and social development mutually promote and influence each other.

This virtuous relationship between mechanical engineers and society can not only accelerate the progress of society, but also promote continuous growth of the field of mechanical engineering and the sustainable development of the mechanical engineering team, which in turn promotes the sustainable development of society.

3.2.1. The importance of engineering ethics

Engineering is an important production and construction process which has a profound impact on people’s lives. Engineering ethics is a code of ethics that adjusts the relationship between engineering and technology, and engineering and society. It is an ethical and moral principle that must be observed in the field of engineering; a basic moral requirement for engineering and technical personnel engaged in engineering design, construction and management. People who are engaged in the profession of engineering must possess the unique ethics of the profession itself [DOU 17].

3.2.2. Problems and causes of engineering ethics

With the continuous development of technology, the harm of environmental pollution and the energy crisis has gradually emerged [WAN 14]. The lack of ethical care for people always occurs during the construction of the engineering project, including other ethical defects caused by the excessive pursuit of profit, etc.

There are many reasons for ethical problems:

1. 1) decision-making mistakes and government supervision imbalances;
2. 2) the ethical system of the enterprise itself is imperfect, and it is negatively affected by the poor corporate culture that pursues economic benefits one-sidedly. It is restricted by the level of science and technology under certain social and historical conditions;
3. 3) the designer has underestimated the engineering risks and lacked professional ethics;
4. 4) weakening of the construction of workers’ sense of social responsibility, etc. [YAN 20].

It is obvious that engineering ethics is becoming more and more important in mechanical engineering. To achieve the sustainable development of mechanical engineering, as a mechanical engineer, observing engineering ethics should be the top priority.

3.2.3. Legal issues in manufacturing

As mechanical engineers, we must strictly abide by relevant laws and regulations in production and construction. If we violate local manufacturing standards or laws, it will lead to very serious consequences, such as the following:

1. 1) observe standardization in the manufacturing field. All aspects of industrial production are closely linked. If one of the links has a size mismatch, it may cause problems within the entire production system;
2. 2) differences in laws and regulations between countries. Many countries have different laws and regulations on industrial production. Before implementing the project, be sure to understand the regulations in the relevant regions to avoid violating the law;
3. 3) naming and modeling a machine should avoid national and religious taboos. We must respect the human rights and religious beliefs of all people, and avoid adopting design concepts that may cause misunderstanding or discrimination.

All in all, while carrying out engineering design, mechanical engineers must be sensitive to, and respectful of relevant laws. Only under the premise of observing morality and the legal system, at the same time, can it be ensured that the project runs smoothly and achieves sustainable development.

3.3.1. Environmental pollution from industrial production is widespread

In industrial production, particularly machine industry processes – traditional casting, forging, welding and other material forming processes, as well as traditional mechanical cutting processes such as turning, grinding, planing, milling, boring, and drilling – discharge a large amount of exhaust gas, wastewater and solid waste (directly or indirectly) and pollute the atmosphere and soil. Wastes such as metal ions, oil, acids, alkalis and organic matter, wastewater with suspended matter, chromium, mercury, lead, copper, cyanide, sulfide, dust, waste gas from organic solvents, metal shavings, slag and other solid waste. At the same time, it is accompanied by noise and vibrations during processing.

When smelting metal, corresponding smelting slag, as well as steam and dust containing heavy metals, are generated. Dust, smoke, noise, various harmful gases and various types of radiation will appear during the casting process of the material. In the plastic processing of the material, the forging hammer and punch will produce noise and vibrations during the work, heating the furnace dust, and cleaning dust will be generated during forging. High-temperature forging will also bring heat radiation. Arc welding, high-frequency electromagnetic waves, radiation, noise, etc. will be produced during the welding process of the material. As part of this process, the outer layer of the electrode and the flux decompose at high temperatures which can create a large amount of harmful dust, such as Fe₂O₃ and manganese, fluorine, etc. Ultraviolet radiation acts on oxygen and nitrogen in the ambient air to produce O₃, NO, NO₂, etc. During gas welding, a large amount of electro-slag is generated due to the production of acetylene gas from calcium carbide.

In metal heat treatment, high-temperature furnaces and high-temperature workpieces will produce heat radiation, soot and slag, and oil fumes. In addition, deoxidizers, such as titanium dioxide and silica gel, will be added to the salt bath furnace to prevent metal oxidation. Various acids, alkalis, salts, etc. and high-frequency electric field radiation are produced during chemical heat treatment. When nitriding the surface, an electric furnace is used to heat and pass ammonia gas. There is leakage of ammonia gas; when the surface is cyanided, the metal is put into the heated cyanide tank, containing sodium cyanide. Sodium cyanide is highly toxic, and will generate cyanide-containing gas and wastewater. When the surface is blackened, alkaline washing is carried out in a mixed solution of sodium hydroxide, carbonic acid and trisodium phosphate, and all waste acid liquid, waste alkaline liquid and sodium chloride gas will be discharged [LI 14].

In short, traditional metallurgy, machining and heat treatment of metal workpieces, etc. will bring unfavorable factors to people and the environment. Mechanical engineers should shoulder the important responsibility of environmental protection. The environmental protection of the human–machine environment should be considered at the early stages of the production claim.

3.3.2. Engineers should know how to control industrial environmental pollution

There are many methods to prevent environmental pollution, such as mechanical dust collectors, electric dust collectors, washing dust collectors and filter dust collectors, used to remove industrial exhaust gas [LI 17]. At the same time, harmful industrial gases can be purified by chemical methods such as absorption, adsorption, incineration, condensation and chemical reaction. However, from the perspective of the ability of engineers, we should master new technologies, new methods, and new material technologies for industrial pollution as soon as possible, and make them mature and perfect through production practices, and strive to achieve the sustainability of the industrial environment.

For example, the treatment method of industrial wastewater can break through the bottleneck of traditional wastewater treatment technology and specify scientific and reasonable purification process technology according to the attributes of wastewater. If it is relatively clean wastewater, such as the cooling water of the high-frequency furnace, it can be simply treated and discharged into a water channel, or treated by cooling or stabilization measures and then recycled. If it is wastewater containing toxic and harmful substances, after in-depth treatment, it can be discharged into the water channel only after meeting the national discharge standards and environmental protection requirements. For this reason, mastering wastewater treatment technology and advanced technology is essential to solve industrial water pollution.

In addition, engineers should abide by the prevention and control of industrial solid waste, and relevant standards and regulations, to mitigate industrial noise. In the process of implementing mechanical engineering technology, engineers should pay more attention to the impact of various links on the environment to ensure the rapid development of machine industry technology and avoid causing serious pollution to the environment, or have serious consequences.

3.6.1. Establish the concept of time, follow the trend of industry development

With the rapid development of science and technology and the emergence of new technologies, mechanical engineers urgently need to keep up with the world’s new technology trends, as well as master the latest theories and technologies within their own industry. Establishing the concept of time can enable mechanical engineers to acquire the latest technical means in the shortest time, so as to create more cutting-edge mechanical products, to obtain greater benefits and serve the effect to the society.

3.6.2. Set up the cost view, strengthen the core competition ability

In today’s market environment, especially in the changing external environment, internal competition is more and more fierce, cost pressures are increasing gradually and each enterprise can survive and develop. Cost saving has become an important measure and, as a mechanical engineer, having a cost concept is the key to making the enterprise competitive. Mechanical engineers can minimize the cost of machinery on the basis of meeting use requirements when designing products, which is the most important means to enhance the core competitiveness of enterprises [LIA 10].

3.6.3. Establish the concept of project risk to avoid the occurrence of major losses

Everything in the world is always evolving and changing, and risks may also extend over time and change dynamically. Mechanical engineers should establish the concept of project risk and focus on cultivating and avoiding risk awareness in the complete cycle of mechanical engineering technology implementation and all links, so as to “prevent risks”. Only with a sense of project risk in mind can we avoid major losses during the project, ensure smooth progress and maximize the profits of the enterprise.

3.7.1. Establish a system concept and give play to the role of system engineering

Today, with the rapid development of modern industry, boundaries between industrialization systems, or different countries, have become increasingly blurred. Because the interconnections and exchanges between countries have been strengthened, the modern machine industry has been promoted; and it is the realization of common goals by machinery companies that has been the main task (improve labor productivity, reduce manufacturing costs, improve quality, product upgrading and so on). Therefore, the field of mechanical engineering is not single or multiple parts manufacturing and assembly but a large structure beyond mechanical systems. This requires mechanical engineers to observe and analyze problems with a systematic perspective when developing products. It is necessary to address the contradictions of parts and components but also to adopt a comprehensive approach from the perspective of the entire product. Engineers also need to consider the interrelationship and impact of each product and the complete set of equipment, and, ultimately, have to consider it from the highest level of the production or engineering system [HUA 15]. If a mechanical engineer does not have a systematic perspective and is not familiar with systems engineering, they would not serve all walks of life well.

3.7.2. Strengthen international exchanges and promote common progress within the industry

With new science and technology, the machinery industry in different countries has advantages and disadvantages. In order to develop their own technologies, they must all take advantage of their own strengths and avoid weaknesses; and must actively participate in international division of labor and cooperation in the production field, in order to save social labor and obtain better benefits. In addition, the new technological revolution is the rapid development of modern economic activities, which is followed by domestic production and sales, products and markets, and the contradiction between the supply of, and demand for resources gradually deepens. To resolve these contradictions, we must have a global perspective, achieve production configuration optimization and promote the goal of common discovery. At the same time, the development of mechanical engineers must embody a global perspective, take the world industrial system as the focus, learn from each other’s strengths in technology, learn from each other in literacy, and unite and cooperate in promoting sustainable human development.