硼化物原位自生增强TiAl基复合材料的组织演化、热变形行为及加工工艺设计  

Microstructure evolution,deformation behavior and manufacture design of TiAl matrix composites reinforced with in-situ borides precipitation

作　　者：李明骜 李娟[1] 周涛 胡励[1] 时来鑫 陈玉勇 徐丽娟[3] 肖树龙[2,3] Ming-ao LI;Juan LI;Tao ZHOU;Li HU;Lai-xin SHI;Yu-yong CHEN;Li-juan XU;Shu-long XIAO(School of Materials Science and Engineering,Chongqing University of Technology,Chongqing 400054,China;National Key Laboratory of Science and Technology on Precision Heat Processing of Metals,Harbin Institute of Technology,Harbin 150001,China;School of Materials Science and Engineering,Harbin Institute of Technology,Harbin 150001,China)

机构地区：[1]重庆理工大学材料科学与工程学院,重庆400054 [2]哈尔滨工业大学金属精密热加工国家级重点实验室,哈尔滨150001 [3]哈尔滨工业大学材料科学与工程学院,哈尔滨150001

出　　处：《Transactions of Nonferrous Metals Society of China》2023年第1期107-127,共21页中国有色金属学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.52101034);the Scientific and Technological Research Program of Chongqing Municipal Education Commission,China(No.KJQN202101138);the Scientific Research Foundation of Chongqing University of Technology,China(No.2020ZDZ003)。

摘　　要：硼元素添加造成的相转变和硼化物析出等因素会对原位TiAl基复合材料显微组织演化及热变形行为产生影响。利用等温压缩实验、扫描电子显微技术以及透射电子显微技术等研究材料的动态再结晶和动态回复机制,并计算出其表现变形激活能为691.506 k J/mol。在1100~1200℃温度区间,再结晶γ和α晶粒的形核长大分别主导α2→α相转变温度上、下的热变形行为。α相的动态回复主导材料在1250℃低应变速率下的热变形行为;同时,硼元素会提高α相含量,降低γ→α和α2→α相转变温度,进而促进加载过程中回复α相晶粒的形核长大。根据新建的本构模型,对TiAl基复合材料的变形机制和加工工艺进行详细阐述.Phase transformation and borides precipitation caused by boron addition influence microstructure evolution and deformation behavior of in-situ TiAl matrix composites.Dynamic recrystallization mechanism and dynamic recovery mechanism were investigated by isothermal compression tests,scanning electron microscopy and transmission electron microscopy,etc.The value of apparent deformation activation energy(Q)of present composites is calculated to be 691.506 k J/mol.In the temperature range of 1100-1200℃,nucleation and growth of recrystallizedγandαgrains promoted by TiB obstacles dominate the deformation below or above Tα2→α.The dynamic recovery ofαphase dominates the deformation in condition with low strain rates at 1250℃.Boron addition increases the fraction ofαphase and decreases the transformation temperatures ofγ→αandα2→α,which promotes the nucleation and growth of recoveredαgrains during the loading.Deformation mechanisms and processing performance were also clarified based on the reestablished constitutive model.

关 键 词：原位TiAl基复合材料 硼化物 变形机制 显微组织演化 动态再结晶 动态回复 

分 类 号：TB33[一般工业技术—材料科学与工程]