半固态加热工艺对7075合金组织与性能的影响  

Effects of Heating Process on Microstructure and Mechanical Property of Semi-solid 7075 Aluminum Alloys

作　　者：李春晓[1] 郑小平[1] 赵丹[1] 田亚强[1] 宋进英[1] 陈连生[1] 

机构地区：[1]华北理工大学教育部现代冶金技术重点实验室,河北唐山063009

出　　处：《铸造技术》2016年第4期701-705,共5页Foundry Technology

基　　金：国家自然科学基金资助项目(51474091);河北省自然科学基金资助项目(E2013209268);河北省高等学校科学技术研究资助项目(Q2012011;Z2013129)

摘　　要：利用应变诱发熔化激活法(SIMA)制备了7075铝合金半固态坯料。研究了半固态加热温度与保温时间对7075铝合金半固态坯料显微组织及压缩性能的影响。结果表明:半固态等温温度越高,球形率越好,液相率越高,初生α-Al固相颗粒的尺寸呈先降后升的趋势,而坯料的抗压强度则呈与之相反的趋势,等温温度595~610℃时达到理想状态;随着保温时间的延长,初生α-Al固相颗粒的球形率越好,颗粒尺寸逐渐增大,液相率无明显变化,而坯料的抗压强度呈先升高后略微下降的趋势,保温时间15~30 min时达到理想状态;在595℃保温30 min时,获得的7075铝合金半固态坯料的初生固相颗粒均匀、细小、圆整,抗压强度可达426.82 MPa。The semi-solid billets of 7075 aluminum alloy were prepared by strain-induced melt activation technology （SIMA）. Effects of heating temperature and holding time on the microstructures and compression performances of the semi-solid billets of 7075 aluminum alloy were investigated. The results show that the higher semi-solid isothermal temperature is, the better the recrystallization nucleation rate is, the higher the rate of liquid phase is. The average grain size of primary o^-A1 solid particles has the tendency of first decreasing and then increasing, however, the compressive strength of semi-solid billets has the opposite trend, which achieves the ideal state at the isothermal temperature of 595~610 ~C. With the holding time prolonging, the spherical rate of primary o^-A1 solid particles is better, but the particle size is gradually increased and the liquid ratio is changed little. The compressive strength of semi-solid billets has the tendency of first increasing and then decreasing slightly, which achieves the ideal state at the holding time for 15-30 min. The optimized parameters are the defbnnation degree of 10%, the heating temperature of 595 ℃ and the holding time of 30 min. Under the above conditions, the semi-sold billets have the maximum compressive strength of 426.82 MPa.

关 键 词：应变诱发熔化激活法 7075铝合金 半固态显微组织 抗压强度 

分 类 号：TG146.21[一般工业技术—材料科学与工程]