摘要
为了解决航天、航空与国防领域对轻质耐热高强韧结构材料迫切需求的难题,采用粉末冶金方法,成功制备出了网状结构(TiBw+(TiZr)5Si3)/TA15复合材料.结果显示,原位反应自生TiB晶须(TiBw)增强相分布在TA15钛合金颗粒周围形成网状结构,(TiZr)5Si3增强相分布在α/β相界面处附近,通过提高"晶界与相界强化"效果、解决"晶界与相界高温弱化"效果、抑制钛合金颗粒与α相组织长大,其室温与高温强度和塑性较TA15钛合金大幅提升,600℃抗拉强度较基体TA15钛合金提高了50%,断裂应变提高了58%.固溶与时效热处理通过改变TA15基体与(TiZr)5Si3增强相组织形态,实现高温强度与塑性大幅改善,如1100℃/40 min/WQ+600℃/5 h/AC固溶与时效热处理后,网状结构(TiBw+(TiZr)5Si3)/TA15复合材料600℃抗拉强度最高达到1010 MPa,700℃断裂应变最高达到38.5%.热处理后强度的提高主要是由于转变β组织形成以及固溶强化与时效析出第二相弥散强化.高温塑性的提高主要归因于组织细化界面增多与整体协调变形能力提升.
Network structured(TiBw+(TiZr)5Si3)/TA15 composites were successfully fabricated using powder metallurgy.This addresses the need in the aerospace and national defense fields for structural materials that are light-weight,heat-resistant,high-strength,and tough.The results showed that in-situ synthesized TiB whisker(TiBw)reinforcement was distributed around TA15 titanium alloy particles,forming a microstructure network.The titanium-zirconium-silicide(TiZr)5Si3 reinforcement was mainly distributed near theα/βphase interface.By improving the grain and phase boundary strengthening effects,solving the high-temperature weakening effects of the grain and phase boundary,and effectively inhibiting the growth of titanium alloy grains andαphase particles,the strength and ductility of the(TiBw+(TiZr)5Si3)/TA15 composites were significantly improved when compared the as-sintered TA15 titanium alloy(at room temperature and high temperatures).The tensile strength at 600℃ was increased by 50%and the fracture strain by 58%when compared to TA15 titanium alloy.Furthermore,the high-temperature strength and ductility of the composites can be substantially improved by solid solution and aging heat treatments.This can modify the morphologies of TA15 matrix and(TiZr)5Si3 reinforcement.After a solid solution and aging heat treatment of (1100℃/40 min/WQ+600℃/5 h/AC),a tensile strength of 1010 MPa at 600℃,and a fracture strain of 38.5%at 700℃ were achieved for the network structured(TiBw+(TiZr)5Si3)/TA15 composites.The strength enhancement after heat treatment is mainly attributed to the formation of the transformationβmicrostructure,solution strengthening,and dispersion strengthening caused by aging precipitation in the second phase.The improvement of high-temperature ductility is mainly due to the microstructure refinement and the coordinated deformation improvement.
作者
黄陆军
孙枫泊
安琦
韩亚坤
刘悦
崔喜平
耿林
HUANG LuJun;SUN FengBo;AN Qi;HAN YaKun;LIU Yue;CUI XiPing;GENG Lin(School of Materials Science and Engineering,Harbin Institute of Technology,Harbin 150001,China)
出处
《中国科学：技术科学》
EI
CSCD
北大核心
2020年第7期935-946,共12页
Scientia Sinica(Technologica)
基金
国家重点研发计划(编号:2017YFB0703100)
广东省重点研发计划(编号:2019B010942001)
国家自然科学基金(批准号:51822103,51731009,51671068)
中央高校基本科研业务费专项资金(编号:HIT.BRETIV.201902)资助项目。
关键词
钛基复合材料
粉末冶金
热处理
网状结构
力学性能
titanium matrix composites
powder metallurgy
heat treatment
network microstructure
mechanical property
