机械搅拌法制备半固态镁合金的组织及性能研究

采用AZ91D镁合金为试验原料,以本课题组自行研制的新型半固态浆料制备与直接流变成形装置为试验设备,研究不同温度、剪切速率下半固态组织的变化规律和不同的成型工艺对其力学性能的影响.研究表明:制备浆料的温度相对越低,剪切速率越大,固相率越高,固相颗粒越细小、均匀、圆整;在3种成型工艺中,半固态挤压铸造的综合力学性能相比来说最好,半固态普通铸造次之,铸态普通铸造最差.

Study on Microstructures and Properties of Semi-solid AZ91D Alloy Produced by Mechanical Stirring

Making magnesium alloy AZ91D as trial material, and a newly self-developed machine for preparing semi-solid slurry and direct fluidized forming as trial equipments, the changing principle of semi-solid microstructure and the influences of different forming technologies on mechanical properties are studied under different temperature or shearing rate. It is showed that the lower temperature of slurry, the higher of shearing rate, meanwhile, the higher solidus, the smaller, symmetricaler and rounded grain. Among the three processes, the properties of the castings in semi-solid casting is better than those in conventional casting but rather poorer than those in squeezing semi-solid process.