固溶冷却速率对全片层亚稳β钛合金α相形貌的影响  

Effect of solid solution cooling rate onαphase morphology of full lamellar metastableβtitanium alloy

作　　者：信云鹏 朱知寿 王新南 商国强 王彦伟 李明兵 XIN Yunpeng;ZHU Zhishou;WANG Xinnan;SHANG Guoqiang;WANG Yanwei;LI Mingbing(AVIC Shaanxi Hongyuan Aviation Forging Company Ltd.,Xianyang 713801,Shaanxi,China;AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China)

机构地区：[1]航空工业陕西宏远航空锻造有限责任公司,陕西咸阳713801 [2]中国航发北京航空材料研究院,北京100095

出　　处：《材料工程》2022年第10期80-86,共7页Journal of Materials Engineering

摘　　要：采用Gleeble热模拟压缩试验机、显微硬度计、扫描电子显微镜(SEM)、透射电子显微镜(TEM)等研究固溶冷却速率对TB17钛合金力学性能和条状α形貌的影响。结果表明:具有网篮组织的TB17钛合金经两相区固溶后,当固溶冷却速率为200℃/min时,合金显微硬度为250HV,随着固溶冷却速率的降低,钛合金显微硬度逐渐增加,当固溶冷却速率降低到1℃/min(炉冷)时,显微硬度增加到320HV。在连续冷却过程中会发生β→α相变,在β基体上析出次生α相,同时条状α相会转变为“叉状”结构;随着固溶冷却速率的降低,“叉状”结构逐渐变粗长大,当固溶冷却速率为40℃/min时,“叉状”结构的宽度约为14 nm,当固溶冷却速率为10℃/min时,“叉状”结构的宽度约为100 nm,当固溶冷却速率为1℃/min(炉冷)时,“叉状”结构的宽度约为300 nm;而当固溶冷却速率大于10℃/min时,条状α相侧面和端面包裹着斜方马氏体α″相,马氏体相的存在促进了α相转变和“叉状”结构的形成。当固溶冷却速率逐渐降低至1℃/min左右相当于炉冷速率时,“叉状”结构变粗,条状α相端面和侧面的斜方马氏体相消失,发生α″→α相变。The effect of solid solution cooling rate on mechanical properties and the morphology of stripαphase of TB17 titanium alloy was studied by Gleeble thermal simulation compression testing machine,microhardness tester,scanning electron microscope(SEM)and transmission electron microscope(TEM).The results show that after solid solution of TB17 titanium alloy with basket-weave microstructure inα+βphase region,when the solid solution cooling rate is 200℃/min,the microhardness of the titanium alloy is 250HV.With the decrease of solid solution cooling rate,the microhardness increases gradually.When the solid solution cooling rate is reduced to 1℃/min(furnace cooling),the microhardness increases to 320HV.And TB17 titanium alloy occursβ→αphase transformation during cooling process,and secondaryαphase precipitates onβmatrix,and the strip-shapedαphase transforms into“fork-like”structure.As the solid solution cooling rate decreases,the“fork-like”structure gradually becomes thicker and larger.When the rate is 40℃/min,the width of the“fork-like”structure is about 14 nm.When the rate is 10℃/min,the width is about 100 nm.When the rate is 1℃/min(furnace cooling),the width is about 300 nm.When the solid solution cooling rate is greater than 10℃/min,the side and end faces of the strip-shapedαphase are wrapped with the rhombohedral martensiteα″phase,and the existence of the martensite phase promotes the transformation ofαphase and the formation of the“fork-like”structure.When the solid solution cooling rate is gradually reduced to about 1℃/min which is equivalent to the furnace cooling rate,the“fork-like”structure becomes thicker,the orthorhombic martensite phase on the end and side faces of the strip-shapedαphase disappears,andα″→αphase transformation occurs.

关 键 词：TB17钛合金 “叉状”结构 固溶冷却速率 马氏体 

分 类 号：TG146.2[一般工业技术—材料科学与工程]