TA15钛合金热压缩变形位错演化分析  

Dislocation Evolution Analysis of TA15 Titanium Alloy during Hot Compression Deformation

作　　者：丁永根 孙建辉[1] 李萍[1] 闻瑶[1] 薛克敏[1] 

机构地区：[1]合肥工业大学材料科学与工程学院,安徽合肥230009

出　　处：《稀有金属与硬质合金》2017年第1期58-62,66,共6页Rare Metals and Cemented Carbides

基　　金：国家自然科学基金(51175137);教育部新世纪优秀人才支持计划(NCET-13-0765)

摘　　要：采用Gleeble—3500热模拟压缩试验机对TA15钛合金进行等温恒应变速率压缩实验,并应用材料分析测试技术(XRD与TEM)和相关定量计算理论(XRD线形傅氏分析法)分析其热压缩变形过程中的位错演化。结果表明,TA15钛合金热压缩变形过程中位错类型主要为柱面(1010)、基面(0002)、锥面(1011)和(110)β面位错,位错密度均在1013~1014 cm-2范围内。当变形温度为950℃且变形量为40%时,随着应变速率的提高,柱面(1010)和(110)β面位错密度几乎不变;当变形量升至60%时,随应变速率的提高,各晶面的位错密度均显著降低。当应变速率为1s-1时,随变形量的增加,平均晶格应变和位错密度均减小;当变形量为60%时,晶格应变降到0.116%~0.138%,位错密度减小到(1.1~1.7)×1014 cm-2。在(α+β)两相区出现了由位错形成的"微观变形带"及位错胞结构;在β单相区板条状马氏体α'相内部位错密度较低,形成位错塞积群,且在位错塞积群和马氏体α'相之间形成高度的应力集中。Some isothermal constant speed compression tests on TA15 titanium alloys were carried out by Gleeble-3500 thermal simulator,the dislocation evolution of TA15 titanium alloy during hot compression deformation was analyzed by materials analysis and testing techniques（XRD and TEM）and related quantitative calculation theory（XRD linear Fourier analysis method）.The results show that the primary dislocations consist of（1010）,（0002）,（1011）and（110）βtypes in deformed TA15 titanium alloy during hot compression deformation,and the dislocation density is in the range of 1013-10^14 cm^-2.When deformation temperature is 950 ℃ and deformation degree is 40%,the dislocation density of（1010）and（110）βtypes is almost unchanged with strain rate increasing.The dislocation density of all types decreases with strain rate increasing at deformation degree of 60%.When strain rate is 1s-1,the average lattice strain and dislocation density decrease with deformation degree increasing.The lattice strain drops to 0.116%-0.138%,and the dislocation density drops to（1.1-1.7）×10^14 cm^-2 at deformation degree of 60%.Microscopic deformation bands and dislocation cell are developed by dislocation in（α＋β）two-phase region.However,the dislocation density is very low in lath martensiteα＇phase to form dislocation pile group,and then highly concentrated stress is formed between dislocation pile group and martensiteα＇phase inβsingle-phase region.

关 键 词：TA15钛合金 位错演化 晶格应变 微观变形带 位错塞积群 

分 类 号：TG146.23[一般工业技术—材料科学与工程]