摘要
借助XRD、SEM、常温拉伸及高温蠕变等试验方法,以一种(TiB+TiC)/Ti-B20新型复合材料为研究对象,采用不同温度固溶及降序双级时效制度进行热处理,研究了显微组织对材料常温拉伸性能和蠕变行为的影响规律及机理。经过降序双级时效处理后,由于增强体和次生α相的双重强化作用,合金的抗拉强度最高可达1734MPa。初生α相可改善合金塑性,但会使弥散强化效果下降。热处理后合金高温蠕变的应力指数n分别为4.66和5.80,蠕变变形机制均为位错攀移。在双相区(790℃)固溶+降序双级时效处理后的合金具有更优异的蠕变性能。初生α相和次生α相对合金的蠕变抗力影响显著,TiB和TiC在蠕变过程中有着重要的强化作用。合金的高温蠕变韧性较高,表现为(TiB+TiC)集中负载的韧性断裂模式。
By means of X-ray diffraction(XRD),scanning electron microscope(SEM),room temperature tensile tests and creep tests,a new type of(TiB+TiC)/Ti-B20 composite was studied,the heat treatment was carried out with solution at different temperature and high-low duplex aging treatment,and the effects of microstructures on tensile properties at room temperature and creep behavior of the material was studied.The results show that the highest tensile strength of the alloy reaches 1734 MPa due to the double strengthening effect of the reinforcement and secondaryαphase after high-low duplex aging treatment.The primaryαphase can improve the plasticity of the alloy,but will reduce dispersion strengthening effect.The high temperature creep stress index n of the alloy after heat treatment is 4.66 and 5.80,respectively,and the creep deformation mechanism is dislocation climbing.The creep properties of the alloys after solution treated in the two-phase zone(790℃)and high-low duplex aging treatment are better.The primaryαphase and secondaryαphase have significant effects on the creep resistance of the alloy.TiB and TiC play an important strengthening role in the creep process.The high temperature creep toughness of the alloy is high,which shows a ductile fracture mode of(TiB+TiC)concentrated load.
作者
徐智博
杨建凯
肖树龙
徐丽娟
田竟
陈玉勇
XU Zhi-bo;YANG Jian-kai;XIAO Shu-long;XU Li-juan;TIAN Jing;CHEN Yu-yong(National Key Laboratory for Precision Hot Processing of Metals,Harbin Institute of Technology,Harbin 150001,China;School of Materials Science and Engineering,Harbin Institute of Technology,Harbin 150001,China)
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2023年第11期3722-3732,共11页
The Chinese Journal of Nonferrous Metals
基金
金属精密热加工国家级重点实验室基金资助项目(6142909200101)。
关键词
Β钛合金
热处理
微观组织
蠕变
断裂机制
βtitanium alloy
heat treatment
microstructure
creep
fracture mechanism Foundation item:Project(6142909200101)supported by the National Key Laboratory for Precision Hot
