Development status of metal matrix composites

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In addition to the characteristics of high specific strength, high specific modulus and low expansion coefficient, metal matrix composites also have good heat resistance, high toughness, aging resistance, high conductivity and high thermal conductivity, as well as radiation resistance, flame retardancy, no moisture absorption and no outgassing. Through the combination of different materials, composite metal materials that meet the requirements of science and technology and industrial production can be manufactured artificially, which can be used in many fields such as mechanical manufacturing, metallurgy, transportation, shipping, pharmaceutical and so on.

1. Research history and development status of metal matrix composites
In the 1960s, because the traditional metal materials could not meet the needs of some countries for the development of high-performance weapons and aviation technology, people began to research and develop new materials, which promoted the development of metal matrix composites. At the end of 1970s, the technology of manufacturing composite materials by powder metallurgy was gradually mature. The use of aluminum alloy materials with SiC particles as reinforcement phase marked the gradual commercialization of aluminum alloy composites. In the 1980s, the development of metal matrix composites entered the blowout period. In 1983, Honda Automobile Company of Japan launched a new product — aluminum piston made of aluminum matrix composite reinforced by ceramic fiber, which made the metal matrix composite gradually turn from military to civilian. In the 1990s, metal matrix composites have been widely used in various military, aerospace and civil industrial fields.

2. Development status of metal matrix composites
2.1 ferrous metal matrix composites
The common ferrous metal matrix composites are steel matrix composites. As the most commonly used functional materials, steel is not widely studied because of its high melting point, large proportion, small specific strength and difficult manufacturing process. However, with the rapid development of modern industry, the workpiece can work normally and stably under harsh working conditions. Therefore, improving and improving the properties of steel matrix has important research significance and practical value. The density of the matrix material can be reduced and its hardness, wear resistance, elastic modulus and other physical properties can be improved by combining the reinforced particles with iron matrix with high specific stiffness and strength. Steel matrix composites are mainly used in cutting tools and other industrial fields.

Steel matrix composites can be divided into surface composites and integral composites. For the integral composite, the common preparation methods are powder metallurgy, in-situ reaction composite, and adding reinforcement particles; the common preparation methods of surface composite technology are casting infiltration method and casting sintering method. Steel matrix composites are usually reinforced by particles, of which titanium carbide, tungsten carbide, silicon carbide and vanadium carbide particles are the most common reinforcement phases.

2.2 non ferrous metal matrix composites
The common non-ferrous metal matrix composites include aluminum matrix, magnesium matrix, titanium matrix and nickel matrix composites. Due to the characteristics of low melting point and low hardness of non-ferrous metals, non-ferrous metal matrix composites are more widely used than ferrous metal matrix composites. At present, in the fields of aerospace, aviation and automobile industry, a variety of light-weight structural parts of non-ferrous metal matrix composites with high specific modulus and high specific strength are widely used.

Aluminum matrix composites have the characteristics of low density and good thermal conductivity of aluminum alloy, but also have higher strength and stiffness. The manufacturing cost of aluminum matrix composites is reduced to a certain extent by more preparation methods and easy molding. At present, there are five kinds of aluminum matrix composites: boron aluminum composite, carbon (graphite) – aluminum composite, silicon carbide aluminum composite, alumina aluminum composite and stainless steel wire aluminum composite.

Magnesium matrix composites are another competitive light metal matrix composites after aluminum matrix composites. Their main characteristics are low density, At the same time, it also has good wear resistance, high temperature resistance, impact resistance, excellent shock absorption performance, good dimensional stability and casting performance; in addition, it also has electromagnetic shielding and hydrogen storage characteristics, which is a kind of excellent structural and functional materials, and is also one of the most promising composite materials in the field of high-tech. however, due to its high price, it is also a kind of excellent structural and functional materials, At present, it is mainly used in aerospace and aviation fields.

Titanium matrix composites can be used at higher temperature than aluminum and magnesium matrix composites, which has attracted great attention. Titanium matrix composites (TMCs) with high specific strength, specific stiffness, good high temperature resistance and corrosion resistance, have broad application prospects in aerospace, automotive and other fields. The research on titanium matrix composites has a history of nearly 40 years in foreign countries, and the development is quite rapid. In situ synthesis technology, fiber coating and other preparation technologies have been successfully used to prepare high-performance titanium matrix composites. Titanium matrix composites can be divided into continuous fiber reinforced (ftmcs) and particle (whisker) reinforced titanium matrix composites (PTMCs). Both of them require good mechanical and processing properties of the matrix materials.

Nickel matrix composite is another common non-ferrous metal matrix composite material. Its excellent high-temperature strength, thermal fatigue resistance, oxidation resistance and hot corrosion resistance make it develop rapidly at home and abroad. It has become an important material for manufacturing important heating parts in ship, aviation and industrial gas turbine engine.

3. Prospect of metal matrix composites
In fact, metal matrix composites are widely used, and the speed and scale of production and development have become one of the important indicators to measure the level of material science and technology in a country. In terms of consumption, the United States, the United Kingdom and Japan are the top three major consumers of metal matrix composites. More than two thirds of the total consumption of metal matrix composites is used by them, which is consistent with their status as developed countries. Metal matrix composites were first used in aviation, aerospace and military fields because of their high cost. With the successful development of new material preparation technology and the continuous emergence of cheap reinforcement, metal matrix composites are more and more used in automobile, machinery, metallurgy, building materials, electric power and other civil fields, showing broad application prospects and huge economic and social benefits. With the continuous development of science and technology, as well as the deepening of research work in related fields, the theoretical basis and preparation technology of metal matrix composites will have greater breakthroughs, and will have more and more broad application prospects in various aspects.