6061合金外熔体温度对7075半固态合金固相颗粒定向生长的影响  

Effect of External Melt Temperature of 6061 Alloy on Directional Growth of Solid Phase Particles in 7075 Semi-solid Alloy

作　　者：梁锦钰 郑小平 吴子娇 于慧 高涵 彭丹洋 侯耿杰 LIANG Jinyu;ZHENG Xiaoping;WU Zijiao;YU Hui;GAO Han;PENG Danyang;HOU Gengjie(School of Metallurgy and Energy,North China University of Science and Technology,Tangshan 063210,China)

机构地区：[1]华北理工大学冶金与能源学院,河北唐山063210

出　　处：《热加工工艺》2021年第2期84-86,91,共4页Hot Working Technology

基　　金：国家自然科学基金项目(51474091);河北省自然科学基金项目(E2017209121);华北理工大学大学生创新训练计划项目(X2017035)。

摘　　要：利用固/液复合铸造技术,将液态6061合金熔体包覆7075合金半固态坯料,制备出包覆型7075/6061双金属复合铸锭。研究了外熔体温度对包覆型7075/6061双金属复合铸锭半固态颗粒生长形态的影响。结果表明:在固/液复合铸造工艺条件下,受到6061合金外熔体温度的影响,内层7075合金半固态固相颗粒沿平行于复合铸锭轴向方向发生了定向生长;随着外熔体温度的升高,内层半固态固相颗粒定向生长速率显著增大;而靠近复合界面处的半固态固相颗粒定向生长速率远大于复合铸锭心部的半固态固相颗粒定向生长速率;外熔体温度越高,半固态显微组织的晶界激活能或表观激活能越低,越有利于半固态固相颗粒发生定向生长。By using solid/liquid composite casting technology, the liquid 6061 alloy melt was coated on 7075 alloy semi-solid billet, and the coated 7075/6061 bimetallic composite ingot was prepared. The effect of melt temperature on the growth morphology of semi-solid particles of the coated 7075/6061 bimetallic composite ingot was studied. The results show that, affected by the melt temperature of 6061 alloy during the solid/liquid composite casting process, the semi-solid particles of the inner 7075 alloy grow in a directional direction parallel to the axial direction of the composite ingot. With the increase of melt temperature, the orientation growth rate of inner semisolid solid particles increases significantly. The directional growth rate of solid particles near the composite interface is much higher than that at the core of the composite ingot. The higher the melt temperature is, the lower the grain boundary activation energy or apparent activation energy of semisolid microstructure is, and the more conducive to the directional growth of semisolid solid particles is.

关 键 词：双金属复合铸锭 半固态显微组织 定向生长 外熔体温度 柱状晶 

分 类 号：TB331[一般工业技术—材料科学与工程] TG244[金属学及工艺—铸造]