C_(sf)/AZ91D复合材料高温变形动态再结晶临界条件  

Critical Conditions of Dynamic Recrystallization of C_(sf)/AZ91D Composites during Hot Deformation Process

作　　者：黄飚[1] 王振军[1] 徐志锋[1] 余欢[1] 邱旭东[1] 尚鸿甫 

机构地区：[1]南昌航空大学轻合金加工科学与技术国防重点学科实验室

出　　处：《特种铸造及有色合金》2017年第4期415-419,共5页Special Casting & Nonferrous Alloys

基　　金：国家自然科学基金资助项目(51365043);江西省研究生创新专项基金资助项目(YC2015S319);江西省教育厅科学技术研究基金资助项目(GJJ1607055);西北工业大学凝固技术国家重点实验室开放基金资助项目(SKLSP201228)

摘　　要：采用真空压力浸渗法制备了短切碳纤维体积分数为15%的AZ91D镁基复合材料(C_sf/AZ91D),通过等温恒应变率压缩试验,研究了复合材料在变形温度为400~460℃、应变速率为0.001~0.1s^(-1)、最大真应变为0.7条件下的流变应力和动态再结晶行为。结果表明,复合材料流变应力曲线呈现显著的动态再结晶软化特征,动态再结晶临界应变随变形温度升高或应变速率降低而减小,其与Z参数之间的函数关系为εc=1.6×10^(-3) Z^(0.037 2);动态再结晶临界应变和峰值应变之间的关系为ε_c=0.385 2ε_p;同等变形条件下,复合材料动态再结晶的临界应变远小于AZ91D镁合金,短切碳纤维促进了基体镁合金动态再结晶发生,同时细化了其再结晶晶粒。The 15%cin volumetric fraction,chopped carbon fibers reinforced magnesium composites（C（sf）/AZ91D）were prepared by vacuum assisted pressure infiltration method,and the isothermal constant strain rate compression experiment of C（sf）/AZ91 Dcomposites was carried out at the deformation temperatures from 400 ℃to 460 ℃ and strain rates from 0.001s（-1） to 1s（-1） and the true strain of 0.7to understand the behavior of flow stress and dynamic recrystallization.The results indicate that the softening mechanism of the dynamic recrystallization is a feature of true stress-true strain curves of C（sf）/AZ91 D composites,and the critical strain is decreased with increasing in temperature or decreasing in strain rate.The functional relationship with parameter Zcan be exhibited asεc=1.6×10（-3） Z（0.037 2） and there enists a linear relationship between critical strain and peak strain,εc=0.385 2εp.The critical strain of the composites is much less than that of magnesium alloy AZ91 D,and the chopped carbon fibers promote the occurrence of dynamic recrystallization of matrix magnesium alloy and refine the recrystallization grains.

关 键 词：Csf/AZ91D复合材料 AZ91D 加工硬化率 动态再结晶 临界应变 

分 类 号：TB333[一般工业技术—材料科学与工程]