TiAl-V-Cr合金近α相区的热变形行为  

Hot deformation behavior of TiAl-V-Cr alloy near-α phase region

作　　者：刘宏武 高帆 冯像征 李臻熙 戴松嵒 王青峰[2] Liu Hongwu;Gao Fan;Feng Xiangzheng;Li Zhenxi;Dai Songyan;Wang Qingfeng(Key Laboratory of Science and Technology on Advanced Titanium Alloys,AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China;State Key Laboratory of Metastable Materials Science and Technology,Yanshan University,Qinhuangdao Hebei 066004,China)

机构地区：[1]中国航发北京航空材料研究院先进钛合金航空科技重点实验室,北京100095 [2]燕山大学亚稳材料制备技术与科学国家重点实验室,河北秦皇岛066004

出　　处：《金属热处理》2025年第1期53-58,共6页Heat Treatment of Metals

基　　金：中国航发自主创新专项(ZZCX-2022-035);稳定支持项目(KZ0C231525)。

摘　　要：采用热物理模拟技术与SEM、EBSD、OM等组织表征方法研究了不同初始组织状态、应变速率及变形量对Ti-44Al-5V-1Cr合金近α相区(1250℃)热变形行为及组织的影响规律。结果表明:合金在1250℃热变形时,相同应变速率条件下,不同初始组织状态的流变应力差异较小,相同组织状态下,应变速率对流变应力的影响相对较大,随着应变速率的降低,流变应力明显降低;合金在近α相区热变形时以发生α相的动态再结晶为主,动态回复为辅,β相的存在能够有效抑制α晶粒的长大;变形程度的增加有助于细化α晶粒尺寸;合金在1250℃大挤压比热挤压加工后获得了较为均匀细小的全片层组织,平均片层尺寸在12~23μm范围内。Hot deformation behavior and microstructure evolution of Ti-44Al-5V-1Cr alloy deformed near the α-phase region(at 1250 ℃) under different conditions as various initial microstructure,strain rates and deformation were investigated by means of thermophysical simulation,SEM,EBSD and OM characterization.The results show that when the deformation temperature is 1250 ℃,the difference of flow stress variations in initial microstructure of the alloy under identical deformation rate are smaller.However,under the same microstructural condition,the strain rate has a relatively significant effect on the flow stress.As the strain rate decreases,the flow stress decreases noticeably.When the alloy is deformed near the α-phase region,the dynamic recrystallization of α phase is dominant,and the dynamic recovery is supplemented,while the β phase effectively suppresses the growth of α grains.In addition,increasing the deformation can facilitate the refinement of α grain size.After extrusion at 1250 ℃ with a high extrusion ratio,the alloy achieves a fine and uniform fully lamellar structure with average lamellar colony sizes of 12-23 μm.

关 键 词：TIAL合金 近α相区 热变形行为 显微组织 

分 类 号：TG139[一般工业技术—材料科学与工程]