热处理温度对TC18钛合金微观组织与冲击性能的影响  

Effect of Heat Treatment Temperature on Microstructure and Impact Performance of TC18 Titanium Alloy

作　　者：翟欣姣 张明玉 宋一新 岳旭 同晓乐 ZHAI Xin-jiao;ZHANG Ming-yu;SONG Yi-xin;YUE Xu;TONG Xiao-le(Xinjiang Xiangrun New Materials Technology Co.,Ltd.,Hami 839000,China;Engineering Research Center of Continuous Extrusion,Dalian Jiaotong University,Dalian 116028,China;Shi Changxu Innovation Center for Advanced Materials,Institute of Metal Research,Chinese Academy of Sciences,Liaoning 110016,China)

机构地区：[1]新疆湘润新材料科技有限公司,新疆哈密839000 [2]大连交通大学连续挤压教育部工程研究中心,辽宁大连116028 [3]中国科学院金属研究所师昌绪先进材料创新中心,辽宁沈阳110016

出　　处：《稀有金属与硬质合金》2024年第5期62-67,共6页Rare Metals and Cemented Carbides

基　　金：新疆维吾尔自治区重点研发计划项目(2022B01029)。

摘　　要：对TC18钛合金棒材进行不同温度的热处理后随炉冷却,使用光学显微镜、扫描电子显微镜、X射线衍射仪、冲击试验机等设备分析热处理温度对合金微观组织、物相组成、冲击性能以及冲击断口微观形貌的影响。结果表明:TC18钛合金经不同温度热处理后,组织中α相尺寸大小、分布情况以及形貌均有不同程度的变化。在热处理温度升高的过程中,组织中大块状α相逐渐消失,长条状α相变得细小,并析出较多细小的针状α相。合金经不同温度热处理并炉冷后的组织中均形成α相以及β相,且随着热处理温度的升高,部分α相和β相的衍射峰强度增大,等轴状和条状α相会使裂纹扩展路径较为平顺,而针状α相与β相能够使合金在受到冲击时分散应力,避免应力集中导致脆裂。合金冲击性能随着热处理温度升高而逐渐降低,当热处理温度为835℃时,合金冲击性能最佳,其冲击吸收功为46J,冲击韧性为57J/cm^(2)。当热处理温度较低(835、855℃)时,合金的冲击断口微观形貌以大韧窝为主,且大韧窝中含有大量小韧窝;当热处理温度较高(875、895℃)时,断口韧窝尺寸变小,并有撕裂棱出现,且空洞尺寸有所增加。TC18 titanium alloy bars were heat treated at different temperatures,and then cooled in the fur-nace.The effects of heat treatment temperature on the microstructure,phase composition,impact perfor-mance and impact fracture micromorphology of the alloy were analyzed by optical microscope,scanning e-lectron microscope,X-ray diffractometer and impact tester.The results show that the size,distribution and morphology ofαphase in TC18 titanium alloy have different degrees of change after heat treatment at dif-ferent temperatures.In the process of increasing the heat treatment temperature,the large blockαphase gradually disappears,the long stripαphase becomes finer,and more fine needleαphase precipitates.The microstructure of the alloy after heat treatment at different temperatures and furnace cooling formsαphase andβphase,and with the increase of heat treatment temperature,the diffraction peak intensity of someαphase andβphase increases.The equiaxed and strip-shapedαphase can make the crack propagation path smoother,while the needleαphase andβphase can disperse the stress of the alloy when it is impacted and avoid brittle fracture caused by stress concentration.The impact performance of the alloy gradually decrea-ses with the increase of heat treatment temperature.When the heat treatment temperature is 835℃,the al-loy has the best impact performance with an impact absorption energy of 46 J and an impact toughness of 57 J/cm^(2).When the heat treatment temperature is low(835℃and 855℃),the impact fracture micromor-phology of the alloy is mainly characterized by large dimples,which contain a large number of small dim-ples.When the heat treatment temperature is high(875℃and 895℃),the fracture dimple size becomes smaller,tearing edges appear,and the void size increases.

关 键 词：TC18钛合金 热处理 炉冷 微观组织 冲击性能 断口形貌 

分 类 号：TG156.1[金属学及工艺—热处理]