Properties Of Iron Matrix Composites Hybrid Reinforced By Different Types Of Copper Plating Ceramic Particles

Because of high strength, high hardness and excellent wear resistance, particulate reinforced iron matrix composites have got more and more research focus on. However, there is a serious incompatibility between ceramic particles and metal matrix, which makes the binding force weak. This reduces the mechanical properties of ceramic particles reinforced metal matrix composites and the influence will be increase with the content of ceramic particles increasing. Copper plating on the surface of ceramic particles can improve the wetting property between particles and iron matrix, which can probably improve the interface binding and mechanical properties of the material. At the same time, varieties sizes of ceramic particles can improve the packing density and reduce stress concentration of material which is expected to produce better enhanced effect on the performance of the composite material. We integrated the above two methods, select different types and different sizes copper plated ceramic particles mixing reinforce the iron matrix composites, using our new preparation technique of current directly heating dynamic hot pressing, and we expect an improvement of high volume fraction composite material properties.We first plated copper on the surface of different sizes (5μm、10μm、15μm、) and different types (SiC、TiC、TiB2、TiN)of ceramic particles, we concluded that electroless copper plating process of different types ceramic particles are universal, and we obtained the best process. Research found that ceramic particle size plays an important role in copper plating under the same conditions, the bigger the ceramic particles, the greater the percent reduction. When the size of ceramic particles is large, the plating speed faster, and the plating layer is rougher. Therefore, to reduce the plating speed, we need to raise the content of chelating agent. The main phases of copper plated ceramic particles are ceramic、Cu、CU2O, thus we increased the hydrogen annealing treatment to eliminate Cu2O.In this research, the mixed reinforcement composites were prepared in particle sizes of5μm,10μm and15μm, in volume fraction of15%,20%and25%, in ratio of2:1,1:1,1:2respectively. Mechanical property compare tests then were carried out and the microstructures were analyzed by scanning electron microscopy and micro-components analyzer to discuss the mechanism of material property improvements.After copper plating, the tensile strength and elongation of ceramic particles mixed reinforcement composites both have increased, and with the increase of mixing ceramic particles volume fraction, the effect is increasing gradually.10μm SiC mixing with10μmTiC, in volume fraction of15%, in volume fraction mix ratio of1:1, composites reinforced by copper plating particles than no plating particles tensile strength increased by7.1%and elongation increased by6.5%.The tensile strength of composites mixing reinforced by different types of ceramic particles are higher than composites reinforced by single type of particles. The SiC particles, which tensile strength enhancement effect is better, to join other ceramic particles reinforced composites, can improve the tensile strength of material. Mixing5μm different types of particles with10vm different types of particles respectively, keep the volume fraction of15%and the mix volume fraction ratio of1:1, the tensile strength of hybrid5μmSiC and10μmTiN reinforced composites than5μmTiN and10μmTiN mixing reinforced composites increased by8.6%; the tensile strength of hybrid5μmSiC and10vmTiC reinforced composites than5μmTiC and10μmTiC mixing reinforced composites increased by13.2%; the tensile strength of hybrid5vmTiC and10μmSiC reinforced composites than5μmTiC and10μmTiC mixing reinforced composites increased by11.7%.The density and tensile strength of the mixed sizes strengthening composites are higher than the single particle size reinforced composites. Compared to the composites reinforced by10μm or5μm single size SiC particles respectively, the tensile strength of the15%SiCp/Fe with volume fraction ratio of1:1improved by2.9%or9.1%respectively. And compared to the composites reinforced by10μm or5μm single size TiC particles respectively, the tensile strength of TiCp/Fe with volume fraction ratio of1:1improved by5.0%and11.9%.For two kinds of particle sizes of ceramic particles, different volume mixing ratios have a great effect on the tensile strength of composite materials. The optimal proportion of10μmSiC and5μmTiC (TiB2) is2:1. And with the content of small size TiC (TiB2) increase, the tensile strength of material decrease.Microstructure shows that the copper still exists around the particles after the sintering, which plays an important role on reducing microscopic defects when the composites were reunited, thus copper plating treatment can significantly improve the performance of the composite materials. We found that different types of ceramic particles mixing enhancement can improve the sintering density, and the microstructure shows that the interface microstructure defect reduced when the composites reinforced by mixed types of ceramic particles, these two points may be the reason of mixed reinforcement.