Aluminum and its alloys are suitable for the matrix of metal matrix composite materials, aluminum matrix composite materials can be continuous fibers, can be short fibers, can also be from spherical to irregular shape of particles. At present, aluminum matrix composites reinforced particle materials such as SiC, AL2O3, BN, etc., intermetallic compounds such as Ni-Al, Fe-Al and Ti-Al are also used to work reinforced particles.
The properties of aluminum matrix composites depend on the properties, content and distribution of matrix alloys and reinforcing materials. Compared with matrix alloys, aluminum matrix composites have many excellent properties.
1 Low density
2 Good dimensional stability
3 Strength, modulus and plasticity: The addition of reinforcement can improve the strength and modulus of aluminum matrix composite, and reduce the plasticity.
4 Wear resistance: High wear resistance is one of the characteristics of aluminum matrix composites (SiC, Al2O3 reinforced).
5 Fatigue and fracture toughness: The fatigue strength of aluminum matrix composites is generally higher than that of base metals, but the fracture toughness is decreased. The main factors that affect the fatigue performance and fracture of aluminum matrix composites are the interface bonding state between the reinforcement and the matrix, the properties of the matrix and the reinforcement itself and the distribution of the reinforcement in the matrix.
6 Thermal performance: The thermal expansion mismatch between the reinforcement and the matrix is difficult to avoid in any composite material. In order to effectively reduce the thermal expansion coefficient of the composite material and keep it hot matched with the semiconductor material or ceramic substrate, low expansion alloys are often selected as the matrix and high volume fraction composites are prepared by using particles of different particle sizes.