Modern Advanced Powder Metallurgy Materials

(1) Powder metallurgy materials in the field of information

Powder metallurgy materials in the information field mainly refer to powder metallurgy soft magnetic materials. Soft magnetic materials can be divided into two types: metal materials and ferrite materials. Among them, the ferrite magnetic material appeared relatively early. The manufacturing technology of this material is extremely limited, and it can only be manufactured by powder metallurgy technology at this stage. Among metals, iron and iron alloys are the main sources for making metal soft magnetic materials, such as silicon steel, phosphorus-iron and iron-cobalt alloys.

In the early 20th century, people have begun to record information with magnetic materials. In 1941, people began to use magnetic powder as a recording medium. Since the 1980s, people have been continuously researching magnetic recording materials, expanding the types of new magnetic recording materials, and greatly promoting the development of magnetic recording technology. demand is increasing. These magnetic materials are very different from traditional magnetic materials, and their main forms of existence are: in the form of particles in organic media; magnetic powder is deposited into a state of magnetic film before use. In addition, magnetic powder is also widely used in the production of magnetic heads. The main function of the magnetic head is to process the existing information. The specific performance is as follows: first, recording audio, video, and text data; Playback; third, the original information can be erased, especially the information that has no use value. At present, aluminum-silicon-iron alloy and aluminum-iron alloy are the main magnetic alloys for making magnetic head materials; in addition, iron oxides can also be used. At present, in the process of manufacturing high-performance rare earth permanent magnet materials, powder metallurgy technology occupies an important position. This kind of technology can produce high-performance NdFeB, which is very popular in the market, and there is a great demand in both military and civilian markets.

(2) Powder metallurgy materials in the energy field

Energy materials are materials that play an important role in the energy field, can promote the development of energy, play a key role in the establishment of a new energy system, and can meet a series of materials required by new energy-saving technologies. According to certain standards, these materials can be divided into two categories: energy storage materials and new energy materials. The application of hydrogen energy is based on the storage and transportation of hydrogen energy. In the 1990s, many countries actively developed hydrogen storage materials. For example, the research and development funds of hydrogen storage technology in the United States account for more than half of all hydrogen energy research funds, and Japan has invested 5 billion US dollars in a one-time investment in the research and development of hydrogen energy power generation technology in the "New Sunshine Plan". At this stage, there are many types of hydrogen storage alloy materials, mainly rare earths, magnesium-nickel and titanium-iron. With the continuous increase of fossil fuel extraction, the earth's energy is increasingly depleted, which urgently needs new alternative energy sources. Among them, nuclear energy is an ideal clean energy, and its development potential is huge. Countries are not far behind in the field of nuclear energy, and they have increased their research and development efforts, all wanting to occupy a place in the world energy market. According to the statistics of relevant departments: Up to now, the power generation of nuclear energy has accounted for about 20% of the world's total power generation. Now, the world's nuclear energy technology is becoming more and more mature. The nuclear power reactors used for power generation are thermal neutron reactors. Such reactors will not produce secondary radiation pollution during operation. It is also relatively cheap, and has become one of the clean energy technologies that many countries with nuclear energy development technology are eagerly pursuing. New energy materials play a vital role in the development of new energy fields. The development and utilization of new energy materials can promote the research and development and promotion of fuel cells and solar cells. At this stage, new energy materials mainly include clean energy such as silicon solar cells and nuclear energy. Powder metallurgy technology plays an important role in the production of new energy materials.

(3) Powder metallurgy materials in the biological field

The research of biomaterials plays a huge role in society, and biotechnology occupies a large proportion of high-tech. my country has included biological materials in the national strategic plan, and biological materials are the main research objects in the future. Some biomaterials can repair the function or structure of organisms, and these materials are biomedical materials. Biomedical materials play an important role in human physical and mental health. Among biological materials, a large number of metal alloys or compounds are powder metallurgy materials.

Since the beginning of the 20th century, people have begun to use metals and alloys as medical biomaterials, and the most widely used is the use of biomaterials to replace human bones. Such as artificial joints and artificial teeth, etc., have a special role in surgery. Stainless steel, titanium and titanium alloys are the most widely used metal materials in medicine. Among them, titanium alloys are biosimilar to human bones, have similar elasticity, wear resistance and corrosion resistance, and are the most widely used metal materials.

Bioceramics have certain physiological characteristics similar to the human body. Therefore, this material is often used to make artificial bones and teeth, and use this material to replace some organs of the human body in part or as a whole to enhance the function of the body. The special physiological behavior of bioceramics is that it has the following characteristics: First, it is similar to the original biological organism, so it can be integrated, and it will not cause damage and irritation to the organism. Tissue matching, with good tissue affinity; second, bioceramics will not cause lesions in the body; third, bioceramics have good chemical properties, certain strength and hardness, but also better flexibility Sex and elasticity, can play the role of the original organism. According to the different chemical reactions of bioceramics, they can be divided into three categories. The first category is biologically inert bioceramics, which mainly include oxide ceramics such as alumina and zirconia, which can be used as artificial joints and weight-bearing. Bone use; the second type is bioceramics with surface activity, this type is mainly bioactive glass-ceramic; the third type is degradable bioceramics, this type includes gypsum ceramics and calcium aluminate ceramics, etc. There will be no impact on the environment.

Powder metallurgy materials used in the military field also play an important role in the military industry, and can greatly improve the performance of weapons and equipment. Therefore, they are widely used in aerospace, weapon manufacturing and other military fields. First of all, the aerospace industry has very strict requirements on material properties, not only requiring the material to have corresponding strength and hardness, but also requiring the material to have high stability, and even strict requirements for its high temperature resistance and corrosion resistance, which requires Materials must have high comprehensive properties. In the aviation industry, a large number of powder metallurgy materials are used. There are mainly two kinds of these powder metallurgy materials. The first is special functional materials represented by anti-friction materials, anti-radiation materials, etc. These materials are mainly used in the instruments and airborne equipment of aircraft and other spacecraft; the other material is high-temperature, high-strength materials, This material is mainly used in engines and can improve the life and performance of the engine.

In the 1970s, the United States used powder metallurgy technology to manufacture engine parts, and the manufacturing technology was relatively mature. In 1973, the United States used 13 parts such as powder turbine disks on its F-104 fighter engine. For aircraft, especially fighter engines, the application of powder metallurgy turbine disks and solidified turbine blades is undoubtedly a huge technological breakthrough, making The F-104 fighter has reached the world's leading level. At the end of the 20th century, Pratt & Whitney in the United States used powder metallurgy technology to manufacture dual-performance powder and used it in the engine of the fifth-generation fighter F22 in the United States, which greatly improved the maneuverability and flexibility of the fighter. Secondly, the characteristics of the nuclear military industry itself lead to special requirements for nuclear materials. Some metal characteristics can only be achieved by powder metallurgy technology, or the performance of materials is further improved after powder metallurgy technology is adopted. Therefore, powder metallurgy materials are an indispensable material in the nuclear military industry.

For a new type of nuclear reactor, it is more necessary to strengthen its safety and prevent nuclear radiation and nuclear leakage from the source, which puts forward higher requirements for nuclear energy energy storage devices. The use of powder metallurgy technology to manufacture energy storage devices can enhance the safety of nuclear reactors After the accident, the reactor can be cooled for about 5 minutes without the support of any power, which can provide valuable time for dealing with the accident, and even effectively reduce the severity of nuclear radiation.