The Effect Of Reinforcement Type And Distribution On Mechanical Properties Some Aluminum Matrix Composites

In recent days, with the development of various high-tech areas, demand for high-performance materials becomes more and more pressing, particle reinforced metal matrix composites (PMMC) has become the object of favor. Although has the good specific stiffness and specific strength. However, low plasticity and low toughness of PMMC, has been an obstacle to hinder its further application. How to increase the plasticity and toughness and ensure the strength of the materials has become the focus of research and development of PMMC.In this paper, the distribution of four different forms of reinforcement aluminum matrix composites are targeted, Namely, uniform distribution of SiCp particle reinforced aluminum matrix composites, SiCp-6061Al/6061Al dual structure reinforced material, Si3N4 network interpenetrating aluminum matrix composites, as well as three-dimensional braided carbon fiber aluminum matrix composites, experimental study the effect of the distribution and shape of reinforcement to mechanical properties, stress-strain cyclic characteristics of composite materials, and on this basis, focus on parameters of the SiCp-Al/Al material, try to explain the effect of the column sizes, types of reinforcement particles, matrix type, heat treatment and a series of factors on the mechanical properties of materials from inner mechanism.Experimental results show that: (1) the elastic modulus of four kinds of materials roughly follow the trend which increased with the particle volume fraction, but there are some deviations between forecast and ROM law, the reason due to the different internal structure of materials. The network distribution of material C would make the matrix to withstand tensile stress and thus reduce the modulus and strength; and material B can withstand the high loads due to the reinforcement bar and a larger matrix which cracks can be amortize so as to enhance the toughness, but also thus reducing the modulus. When the stress amplitude is small, modulus of materials after pre-mechanical cycling increased with the stress amplitude, and down when it is higher. Primary due to the increase of internal dislocation density. There is a certain stress amplitude, making the material yield strength to reach the best.(2) for the SiCp-Al/Al material, the size of reinforcement bar significantly affected the fracture toughness, relationship of the size and toughness is not monotonous, but at some point to reach extreme. The result would be totally opposite when the matrix is different. Compared to B4C and SiCp, Although the substrate-binding of Al2O3 is good, the particle size is too large and result to decline in strength and toughness. Size of reinforcement bar significantly affected the fatigue life of materials, the larger the matrix space can make more resistance to crack propagation.