预变形SiC_P/AZ61复合材料在半固态等温热处理时的组织演变  

Microstructure Evolution of Pre-deformed SiC_P/AZ61 Composite During Semi-solid Isothermal Heat Treatment

作　　者：张发云[1,2] 

机构地区：[1]新余学院新能源科学与工程学院,江西新余338004 [2]江西省高等学校硅材料重点实验室,江西新余338004

出　　处：《热加工工艺》2013年第16期104-106,109,共4页Hot Working Technology

基　　金：国家自然科学基金(50765005);江西省教育厅科技项目(11739)

摘　　要：采用半固态等温热处理法研究了预变形SiCP/AZ61复合材料的微观组织变化。研究表明,SiCP/AZ61复合材料经15%预变形后,其最佳非枝晶组织的制备工艺参数：加热温度600℃、保温30～60min,这一温度区间可获得均匀、圆整的球状组织;当加热温度高于605℃时,复合材料试样液相体积分数较高,产生严重变形和流淌,难以满足后续半固态触变成形时的组织要求。变形后SiCP/AZ61复合材料组织演化机制分析表明,在加热初期,晶粒主要呈熔合合并;加热中后期,晶粒主要通过熔化分离、球化并粗化长大。The microstructure evolution of pre-deformed SiCp/AZ61 composite by semi-solid isothermal heat treatment was investigated. The results indicate that the optimum technological parameters for preparing non dendrite microstructure are the reheating temperature of 600 ℃ and isothermal holding time of 30-60 rain after 15% pre-deformation of the composite. At the temperature range, the uniform and round globular microstructure can be obtained. When the heating temperature is above 605℃, the liquid volume fraction of the composite modified is high. The specimen generates serious deformation and flowing, which can not satisfy the requirement of the microstructure of thixoforming. The analysis of evolution mechanism of pre-deformed SiCp/AZ61 composite microstructure show that the in the initial stage of heating, grain basically can present the coalescence; in later heating period, grain boundary grows bY melting separation, spheroidization and coarsening.

关 键 词：SICP AZ61复合材料 半固态等温热处理法 组织演变 预变形 

分 类 号：TB333[一般工业技术—材料科学与工程]