摘要
目的为了进一步提高(TiB_(w)+(TiZr)_(5)Si_(3))/TA15的耐高温性能与强韧性,对烧结态(TiB_(w)+(TiZr)_(5)Si_(3))/TA15复合材料进行热轧制研究。方法利用光学显微镜(OM)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)对烧结态与轧制态的钛基复合材料进行组织观察。使用电子万能试验机和电子蠕变试验机对烧结态与轧制态的复合材料进行性能表征。结果通过热轧制变形,复合材料的显微组织发生细化,内部产生大量位错,(TiZr)_(5)Si_(3)硅化物发生固溶并重新析出,数量增多且更细小弥散,随着轧制变形量的增加,TiB晶须折断现象加重,α相由片层状向等轴状转变。当变形量为60%时,室温抗拉强度为1238 MPa,较烧结态提高11.8%,伸长率为10.1%,较烧结态提高近1倍,700℃下的抗拉强度和伸长率分别为508 MPa和28.6%,较烧结态分别提高了13%和47%。变形量为40%和60%时,复合材料的持久断裂时间分别为39.8 h和37.3 h,较烧结态分别提高了26.3%和18.4%。结论热轧制过程带来的形变强化、热处理强化作用,有效提高了(TiB_(w)+(TiZr)_(5)Si_(3))/TA15复合材料的室温及高温强韧性水平。抗蠕变性能的变化主要归因于轧制带来的组织等轴化、增强相的折断及取向改变等。
In order to modify the high temperature durability and toughness of the structural materials in aerospace and de-fense fields,the hot rolling process is carried out on the assintered(TiB_(w)+(TiZr)_(5)Si_(3))/TA15 composites by powder metallurgy.After hot rolling,the microstructure of the composites is remarkably refined,and a large number of dislocations are generated in the composites.The silicides of(TiZr)_(5)Si_(3)are solid soluted and reprecipitated,and become fine particles distributed around the thin stripβphase.The number of silicides is increased and the distribution was more uniform.The tensile properties of the as-rolled(TiB_(w)+(TiZr)_(5)Si_(3))/TA15 composites at room temperature and high temperatures are significantly improved due to the deformation and heat treatment strengthening effects after hot rolling process.For example,when the rolling reduction is 60%,the ultimate tensile strength at room temperature is increased by 11.8%,while the fracture strain by 50%,compared with those of the assintered(TiB_(w)+(TiZr)_(5)Si_(3))/TA15 composites.Moreover,the strength at 700℃is increased from 449 MPa to 508 MPa,which is increased by 13%and the elongation is increased by 47%.Compared with the assintered(TiB_(w)+(TiZr)_(5)Si_(3))/TA15 composites,the creep resistance of the as-rolled(TiB_(w)+(TiZr)_(5)Si_(3))/TA15 composites is significantly improved.When the rolling reduction is 40%and 60%,the rupture time of the composites is 39.8 h and 37.3 h respectively,which are increased by 26.3%and 18.4%compared with the assintered composites.However,the creep resistance of the composite is decreased with higher rolling reduction of 80%.The variation of the creep resistance can be attributed to microstructure globularization,reinforcement fracture and directional distribution.
作者
陈润
安琦
张芮
刘悦
王帅
黄陆军
耿林
CHEN Run;AN Qi;ZHANG Rui;LIU Yue;WANG Shuai;HUANG Lu-jun;GENG Lin(School of Materials Science and Engineering,Harbin Institute of Technology,Harbin 150001,China)
出处
《精密成形工程》
北大核心
2021年第3期1-8,共8页
Journal of Netshape Forming Engineering
基金
国家自然科学基金(51822103,51731009)
国家重点研发计划(2017YFB0703100)
广东省重点领域研发计划(2019B010942001)。
关键词
钛基复合材料
网状结构
粉末冶金
力学性能
titanium matrix composites
net structure
powder metallurgy
mechanical property
