Processing And Properties Of SiCp-Cu Reinforced ZA40 Composites

High-aluminum zinc-based(ZA)alloy is a very promising wear-resistant materials owing to its soft foundation and hard pHase structure.ZA alloy has gradually been used to replace the copper-based alloy to prepare wear-resistant parts in industry at this stage.As a friction-reducing material,the wear resistance of it will decrease,if it works in a high temperature due to its low melting point.The ZA alloy has a hexagonal close-packed(hcp)crystal structure,so it lead to poor plasticity,limiting the scope of application.It can improve the high-temperature mechanical properties and wear resistance by adding SiCp to prepare the SiCp particle-reinforced high aluminum Zinc-based(ZA)matrix composites.In this study,SiCp reinforced ZA matrix composites were prepared by the process of semi-solid mechanical stirring technique.This paper investigated the processes of pre-treatment of SiC particles,homodisperse of SiCp in high aluminum zinc.Micro-structure,mechanical properties and the abrasion resistance of SiCp Particles Reinforced ZA matrix Composites was studied in this paper.SiCp is treated by chemical copper plating to improve the wettabilitybetween the ZA alloy and SiCp.This paper analyzed how the pre-treatment before plating,the plating process and the parameters on the plating impacting the effect of copper coated and the rate of plating.And the optimal parameters are determined.The SiCp-Cu/ZA40 composites with different size and content of SiCp-Cu were prepared by the method of semi-solid mechanical stirring.The effects of the size and content of SiCp-Cu on the mechanical properties and friction properties of the composites were studied by means of scanning electron microscopy,X-ray diffraction,friction and wear testing machine and tensile test,concluded as follow.(1)The effect of chemical copper plating in the surface of SiCp is best,when Temperature 40?,and Potassium sodium tartrate 24g/L,copper sulfate 16g/L in electroless plating solution.(2)When the SiCp-Cu content is the same,the finer the SiCp-Cu,the clearer the cleavage of the?-pHase dendrites,the finer and uniform the organization.(3)The hardness of SiCp-Cu/ZA40 composites increases with the increase of SiCp-Cu content,and the smaller the size of SiCp-Cu,the more obvious the effect of hardness increase.(4)The tensile strength of SiCp-Cu/ZA40 is affected by multiple factors.When the SiCp-Cu size is 1?m and the content is 0.5wt%,the tensile strength of SiCp-Cu/ZA40 is 453 MPa and 52% higher than ZA40.(5)The wear mechanism of SiCp-Cu/ZA 40 composites is abrasive wear and adhesion wear.(6)When the size and the addition amount of SiCp-Cu are 4?m and 1.5wt% respectively,its wear is the lowest,wear-resisting performance is best.