热处理调控α+β两相钛合金板材的力学及导电性能  

Mechanical Properties and Electrical Conductivity ofα+βTitanium Alloy Sheet Regulated by Heat Treatment

作　　者：张术钱 马英杰[2] 王倩 齐敏 黄森森[2] 雷家峰[2] 杨锐[2] ZHANG Shuqian;MA Yingjie;WANG Qian;QI Min;HUANG Sensen;LEI Jiafeng;YANG Rui(School of Materials Science and Engineering,University of Science and Technology of China,Shenyang 110016,China;Shi-changxu Innovation Center for Advanced Materials,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China)

机构地区：[1]中国科学技术大学材料科学与工程学院,沈阳110016 [2]中国科学院金属研究所师昌绪先进材料创新中心,沈阳110016

出　　处：《金属学报》2024年第12期1622-1636,共15页Acta Metallurgica Sinica

基　　金：国家重点研发计划项目No.2021YFC2801801;国家自然科学基金项目No.51871225。

摘　　要：热处理可有效调节两相钛合金的强塑性关系,但是热处理对其导电性能的影响还不明确。本工作研究了退火温度对Ti-6Al-3Mo-2V-1Cr-2Sn-2Zr合金板材显微组织、力学性能及导电性能的影响。结果表明,轧制钛合金板材形成了沿轧向(RD)排列的条带状组织,板材织构类型为T型织构。板材在两相区退火后,双态组织中的αs/β(αs为次生α相)界面强化导致板材屈服强度升高,延伸率下降。屈服强度呈现明显各向异性,沿板材横向(TD)的屈服强度更高。而在单相区退火后,αs相明显粗化,且有晶界α相(αGB)相析出,板材延伸率急剧下降。αs相变体选择诱发形成了R型织构和c轴方向沿ND向RD偏转20°~30°的新织构,此时沿板材TD的屈服强度仍高于沿RD的屈服强度,屈服强度各向异性受织构的影响减弱。电阻率分析结果表明,钛合金板材由于条带状组织及T型织构的形成,使沿板材RD的电阻率更高。而条带状组织消失及R型织构体积分数增加,使电阻率各向异性减弱。Eddy current loss,which produces Joule heat and reduces transmission efficiency,is inevitable when the magnetic coupling is running.Magnetic couplings with high electrical resistivity alloys,such as titanium alloy,have been proven to be effective in suppressing the eddy currents.The Ti-6Al-3Mo-2V-1Cr-2Sn-2Zr alloy sheet was aα+βtitanium alloy for marine engineering with high specific strength and electrical resistivity,which was used in magnetic couplings to suppress the eddy currents.In this study,the effect of annealing temperature on the microstructure,mechanical properties,and electri-cal conductivity of the Ti-6Al-3Mo-2V-1Cr-2Sn-2Zr alloy sheet was investigated.The results revealed that the band structure was arranged along the rolling direction(RD),and the as-rolled titanium alloy sheet showed a typical T-type texture with the c-axis of theαphase approximately parallel to the transverse direction(TD).A considerable increase in tensile strength and decrease in elongation afterα+βregion(850-920oC)annealing was thought to result from the strengthening of secondaryα/βinterfaces in the bimodal structure.Simultaneously,theαphase showed both T-type and R-type textures,which also resulted in higher yield strength along the TD of the sheet.Additionally,when the sheet suffered aβphase region annealing(950-1000oC),the elongation immediately decreased due to the coarseness and precipitation of the secondaryαand grain boundaryαphases,respectively.Meanwhile,the annealed sheet showed an R-type and a new B-type texture components with basal poles rotated 20°-30°away from the normal direction(ND)toward the RD under the influence of variant selection of secondaryαphase.However,the yield strength along the TD was still higher than that in the RD,indicating that the effect of texture on yield strength anisotropy was reduced.Finally,the electrical resistivity analysis of the titanium alloy sheet indicated that the electrical resistivity along the RD of the sheet was higher when the band structure was formed and th

关 键 词：α + β 钛合金板材 退火处理 显微组织 各向异性 拉伸性能 电阻率 

分 类 号：TG146[一般工业技术—材料科学与工程]