复合颗粒铸渗制备钢基表面复合材料研究

Research on Steel Based Surface Composites Prepared by Cast Infiltration with Special Composite Particles

将WC和Cr-Fe粉末混合并压制成大粒度的复合颗粒,涂覆于铸型型腔中,然后浇注45钢液进行铸渗实验,并对铸渗层的厚度、组成及铸渗机制进行了研究。结果表明,采用复合颗粒铸渗法得到比普通铸渗法更厚的且无缺陷的铸渗复合层,该复合层由熔合层和钎焊层组成。铸渗机制为高温金属液先渗入复合大颗粒间的通道,将颗粒包围,然后渗入复合颗粒中小颗粒的间隙,最后凝固结晶,形成铸渗复合层。

Big size of composite particles were prepared by mixing WC with Cr-Fe powder and then pressing.The composites particles were coated on the surface of sand cast mould,and then 45 steel liquid was poured in the cast mould.The thickness,composition of the cast infiltration layer and the cast infiltration mechanism were studied.The results show that,the surface composite layer without defects are obtained using this special composite particles cast infiltration.The coating prepared by this method is thicker than that of by common cast infiltration.The surface composites layer consist of melting layer and brazing layer.The mechanism of the cast infiltration is that high temperature cast steel liquid infiltrates into the gaps between composite particles firstly,and then the gaps between small particles in the composite particles,in the end,the liquid steel solidifies into cast infiltration surface composites layer.