半固态加工技术制备金属合金粉末

Metal Alloy Powder Produced by Semi-Solid Processing

摘要:

采用自制半固态搅拌装置研究了Sn．15Pb（质量分数，％下同）合金在搅拌条件下固相分数大于0．6时的连续冷却凝固行为。组织分析结果表明：当搅拌停止温度在合金固相线温度附近时，所获半固态组织出现非常明显的液固两相分离现象，且所获固相组织为分散的类球状颗粒。利用此现象，获得了一种新型金属合金粉末制备方法一半固态金属合金粉末制备法。采用该方法可以实现粉末颗粒内部无夹杂、无孔洞，外部裹有低熔点共晶薄膜。颗粒为以单晶方式生长的金属合金粉末。

Abstract:

Using self-made semi-solid mechanical stirring process system, the solidification behavior of Pb-15wt% Sn alloy semi-solid slurry with solid fraction beyond 0.6 was investigated under stirring condition. A detailed microstructural analysis of the solid phase was carried out. The results show that the solid-liquid separation is obvious in the samples with the solid fraction beyond 0.6 and the solid phase is dispersed quasi-globular particles. Based on these results, a kind of single-crystal powders coated with Pb-Sn eutectic was made by continuous stirring and cooling under the semi-solid state and a new method for preparing metal powder is developed. The analysis and discussion indicate that this approach can reduce the content of oxide and impurity in the powder.