金属颗粒增强钛基复合材料的热变形行为  

Hot deformation behavior and processing map of metal particle reinforced titanium matrix composites

作　　者：刘伟 陆锐宇 李娜[1] 叶子辉 曹远奎[1] 刘彬[1] LIU Wei;LU Ruiyu;LI Na;YE Zihui;CAO Yuankui;LIU Bin(State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China)

机构地区：[1]中南大学粉末冶金国家重点实验室,湖南长沙410083

出　　处：《粉末冶金工业》2024年第6期84-94,共11页Powder Metallurgy Industry

基　　金：国家自然科学基金资助项目(52104365)

摘　　要：采用金属颗粒增强钛基复合材料有利于获得高的强度并维持良好塑性,但该类材料流变抗力较高,热变形加工较困难。本研究通过热压烧结制备了钨颗粒增强钛基复合材料,研究了复合材料在温度为700~1100℃和应变速率为0.001~10 s^(-1)条件下的热变形行为,构建了基于真应变修正的热加工图,并分析了热变形过程的组织演变。结果表明,Ti-20W复合材料中钨颗粒在(α+β)-Ti双相钛基体中均匀分布,两者界面处为β-Ti相区,具有优异的力学性能。Ti-20W复合材料的热变形行为具有明显分区特征,在(α+β)-Ti双相区热变形过程中变形激活能为793.7 kJ/mol,动态再结晶起主要流变软化作用,作用效果强于加工硬化;在β-Ti单相区热变形过程中变形激活能为264.6 kJ/mol,动态回复起主要流变软化作用,作用效果弱于加工硬化。根据热加工图优化了Ti-20W复合材料的热加工工艺窗口,其中在(α+β)-Ti双相区的合适加工参数为0.2≤ε≤0.3;740℃≤T≤800℃;0.001 s^(-1)≤ε·≤0.015 s^(-1);在β-Ti单相区的合适加工参数为ε≥0.4;975℃≤T≤1100℃;0.001 s^(-1)≤ε·≤0.02 s^(-1)。The use of metal particle reinforced titanium matrix composites is beneficial to obtain high strength and maintain good plasticity,but the rheological resistance of this kind of material is high,and the hot deformation processing is difficult.In this study,tungsten particle reinforced titanium matrix composites were prepared by hot pressing sintering.The hot deformation behavior of the composites at 700-1100℃and strain rate of 0.001-10 s^(-1)was studied.The hot processing map based on true strain correction was constructed,and the microstructure evolution of the hot deformation processing was analyzed.The results show that the tungsten particles in the Ti-20W composite are uniformly distributed in the(α+β)-Ti dual-phase titanium matrix,and the interface between the two is theβ-Ti phase region,which has excellent mechanical properties.The hot deformation behavior of Ti-20W composites has obvious partition characteristics.The deformation activation energy is 793.7 kJ/mol in the hot deformation process of(α+β)-Ti two-phase region.Dynamic recrystallization plays a major role in flow softening,and the effect is stronger than that of work hardening.The deformation activation energy is 264.6 kJ/mol in the hot deformation process ofβ-Ti single-phase region.Dynamic recovery plays a major role in rheological softening,and the effect is weaker than that of work hardening.According to the hot processing map,the hot processing window of Ti-20W composites is optimized,and the suitable processing parameters in the(α+β)-Ti dual-phase region are 0.2≤ε≤0.3;740℃≤T≤800℃;0.001 s^(-1)≤ε·≤0.015 s^(-1);the suitable processing parameters in theβ-Ti single-phase region areε≥0.4;975℃≤T≤1100℃;0.001 s^(-1)≤ε·≤0.02 s^(-1).

关 键 词：钛基复合材料 粉末冶金 热变形行为 热加工图 微观组织 

分 类 号：TB331[一般工业技术—材料科学与工程]