Optimization of the Metallurgical Process of (Ni_xSi+C)/Cu Composite Materials Based on Orthogonal Test

Abstract

In order to optimize the parameters of the powder metallurgy process of (NixSi+C)/Cu composite materials，orthogonal tests were designed to study the effects of mixing method，sintering temperature and sintering time on the microstructure and mechanical properties of(NixSi+C)/Cu composite materials.Results showed that a low mixing energy would lead to an uneven dispersion of SiC particles，and SiC particles that didn’t take part in the reaction would remain at the boundary of the powders in the composite prepared；a high mixing energy would lead to serious deformation of the powders and increase the diffusion ability of the elements in the sintering process，making the mixture of Ni3Si and C at the boundary of the powder in the composite prepared after the reaction show a complete network structure.The increase of sintering temperature and sintering time would result in an increase of the amount of Ni3Si precipitated at the boundary of powders in the composite and an increase of the density of the composite.In addition，the conductivity and hardness showed an increasing trend.The parameter combination of the metallurgical preparation process of (NixSi+C)/Cu composite materials that could obtain the best conductivity and hardness was as follows:a vibration mixing，a pellet ratio of 1 ∶5，a sintering temperature of 950 ℃and a sintering time of 120 min.Under these conditions，the density，conductivity and Vickers hardness of the samples were verified，and the verification results were all higher than those of the samples in the orthogonal tests，which would provide an important theoretical and practical reference for the subsequent preparation of(NixSi+C)/Cu composite materials with excellent properties.

Keywords

• (nixsi+c)/cu composite material|hot pressing sintering|orthogonal test|metallurgical process|performance optimization