摘要
本文采用真空热压烧结+热挤压+退火工艺制备细晶TC4钛合金,对制备过程中钛合金的微观组织与力学性能演变规律进行研究。结果表明,热压烧结态TC4钛合金主要由α和β相组成,α相以等轴状分布,而β相则以细长片层状/针状分布于α相晶粒内部或晶界处。热挤压可以使合金中的α和β相尺寸明显降低,形成板条状细晶,从而使TC4钛合金室温抗拉强度从热压烧结态的837 MPa提高至983 MPa,但此时TC4钛合金的断后伸长率最低,为9.6%。进一步的退火能够使热挤压态TC4钛合金发生回复和再结晶,β相由片层状/针状向颗粒状转变,分布于α相晶界处,从而有利于TC4钛合金塑韧性的提高。因此,经过热压烧结+热挤压+退火处理得到的细晶TC4钛合金具有较为优异的综合性能。
In the present work,fine-grained TC4 titanium alloy was prepared by the means of vacuum hot pressing sintering+hot extrusion+annealing treatment.The evolution of microstructure and mechanical properties of titanium alloy during the preparation were studied.The results show that the hot-pressed sintered TC4 titanium alloy is mainly composed ofαandβphase,αphase is distributed in an equiaxial manner andβphase is distributed in the inner grain or grain boundary ofαphase with an elongated lamellar/acicular.After hot extrusion,the grain sizes of TC4 titanium alloy obtained by vacuum hot-pressing sintering can be significantly reduced to form fine-grained microstructure,which is benefit for the improvement of tensile strength from 837 MPa to 983 MPa.However,the fracture elongation is the lowest at 9.6%.Further annealing can restore and recrystallize the hot extruded TC4 titanium alloy,especially theβphase grains formed equiaxed grains and distributed around theαgrains in a spot-like manner,which is beneficial to improve the plasticity and toughness of TC4 titanium alloy.Therefore,the fine-grained TC4 titanium alloy obtained by hot pressing sintering+hot extrusion+annealing treatment has relatively excellent comprehensive properties.
作者
张辉
赵亚斌
潘爱琼
ZHANG Hui;ZHAO Yabin;PAN Aiqiong(School of Mechanical Engineering,Zhengzhou University of Science&Technology,Zhengzhou 450064,China)
出处
《粉末冶金工业》
CAS
北大核心
2021年第5期66-70,共5页
Powder Metallurgy Industry
基金
河南省科技厅重点科技攻关项目(212102210348)。
关键词
TC4钛合金
热压烧结
热挤压
细晶
TC4 titanium alloy
hot pressing sintering
hot extrusion
fine-grained
作者简介
张辉(1985—),男,硕士,副教授,主要研究方向为先进材料加工技术。
