热变形对TA19闪光焊接接头组织均匀化的影响  

Effect of Hot Deformation on Microstructure Homogenization of Flash Welded TA19 Alloy

作　　者：梁运兴[1,2,3] 王龙祥 魏志坚 徐平伟 梁益龙[2,3,5] 梁宇 Liang Yunxing;Wang Longxiang;Wei Zhijian;Xu Pingwei;Liang Yilong;Liang Yu(Guizhou University,Guiyang 550025,China;Guizhou Key Laboratory for Mechanical Behavior and Microstructure of Materials,Guiyang 550025,China;The Key Laboratory for Mechanical Behavior and Microstructure of Materials,Guiyang 550025,China;Guizhou Anda Aviation Forging Co.,Ltd,Anshun 561005,China)

机构地区：[1]贵州大学材料与冶金学院,贵州贵阳550025 [2]贵州省材料结构与强度重点实验室,贵州贵阳550025 [3]高性能金属结构材料与制造技术国家地方联合工程实验室,贵州贵阳550025 [4]贵州安大航空锻造有限责任公司,贵州安顺561005 [5]贵州大学,贵州贵阳550025

出　　处：《稀有金属材料与工程》2020年第5期1757-1765,共9页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51761003)。

摘　　要：为消除TA19闪光焊接接头的组织不均匀性,改善闪光焊接TA19的综合性能,利用Gleeble3500热模拟试验机对TA19闪光焊接头在变形温度900~980℃,变形量30%、60%,变形速率0.01~1 s-1条件下进行等温恒定速率热压缩试验,以研究其组织在不同变形参数下的转变特征。结果表明,焊接接头试样在压缩过程中流变应力-应变曲线呈现动态软化趋势,在低变形速率条件下片状α相动态回复、动态再结晶过程充分发生,促进其宽度尺寸的增加,β相楔入导致片状α相断开。随变形量与变形温度的增加,在动态再结晶以及元素扩散作用下,片层α相等轴化比例逐渐提高。变形过程中有残留β相被破碎,部分转变为富Mo的颗粒分布在α相基体上。在随后的热处理过程,α基体上富Mo颗粒回溶到β相,β相长大完成对片层α相的分割,α相进一步通过静态再结晶完成等轴化。闪光焊接试样在980℃、变形速率0.01 s-1、60%变形量下变形后,经930℃,1 h+590℃,4 h空冷的退火处理,可充分实现焊缝组织的等轴化转变,热处理后焊接接头组织以等轴组织为主,组织均匀性明显改善。In order to eliminate the microstructure inhomogeneity of TA19 flash welding joint and improve its comprehensive properties, an isothermal constant rate hot compression test was performed using Gleeble3500 thermal simulation testing machine on TA19 flash welding joint under the condition of deformation temperature 900~980℃, deformation 30%, 60%, and deformation rate 0.01~1 s-1, to research microstructure change characteristics of the welding joint under different deformation parameters. The results show that the rheological stress-strain curve of the welded specimen indicates a dynamic softening trend during the compression process, and the recovery and recrystallization of the flaked α phase are sufficient under the condition of low deformation rate, which promotes the increase of its width and size, and the wedge of β phase results in the disconnection of the flaked α phase. With the increase of deformation amount and deformation temperature, under the action of dynamic recrystallization and element diffusion, the equiaxial ratio of flaked α increases gradually. In the process of deformation, residual β phases are broken and some of them are transformed into Mo-rich particles which are distributed on the α phase matrix. In the subsequent heat treatment process, Mo rich particles on the matrix are dissolved back into the β phase, which grows up to complete the segmentation of the α phase, and it is further equiaxialized by static recrystallization. Flash welding specimens after 980℃, 0.01 s-1, 60% deformation followed by air cooling annealing treatment of 930℃, 1 h + 590℃, 4 h can fully realize equiaxial transition of the weld microstructure. After heat treatment, the welding joint is mainly composed of equiaxial microstructure, and the microstructure uniformity is obviously improved.

关 键 词：近Α钛合金 闪光焊 热变形 组织均匀化 

分 类 号：TG166.5[金属学及工艺—热处理]