铝─钢双金属复合铸件研制

Study on Aluminium-steel Bimetal Castings

用钢套铸接表面预电镀纯金属、浸Ａｌ－Ｓｉ基合金后立即浇注的方法制造了“钢套内表面浇注铝合金”结构形式的铝钢双金属铸件。优化了双金属铸件铸造工艺、热处理工艺；研究了钢套铸接表面金属预镀层和双金属界面附近的合金元素对双金属铸件铸态及热处理后界面过渡层裂纹和抗剪强度的影响。获得的双金属铸件铸态界面过渡层厚度为０．００７～０．０１８ｍｍ，界面剪切强度为５０～９４ＭＰａ，热处理后界面过渡层增厚，界面剪切强度明显下降。

The bimetal Castings of Al-lined steel sleeve were produced by a method in which,first,the inner surface of steel sleeve to be conjoined electroplates a layer of pure metal and immerses into Al-Si alloy melt,then immediately cast.The foundry technology and heat treatment processes were optimized, the effects of the alloying elements in the preplating layer on the junction surface of steel sleeve and nearby bimetal interface on the cracking and shearing strength of transition layer at the interface for as-cast and heattreated bimetal castings were also studied, the results revealed that the transition layer thickness of 0.007￣0. 018mm and shearing strength of 50￣94MPa can be achieved at the interface of as-cast bimetal castings, while the thickness of transition layer increased and shearing strength reduced after heat treatment.