摘要
使用低成本的TiH_(2)粉末代替纯钛粉,通过添加B4C原位生成TiB和TiC两种增强相,经过真空无压烧结及热挤压工艺制备出具有优异力学性能的Ti/(TiB+TiC)钛基复合材料,分析了制备工艺和增强相对复合材料组织与性能的影响。结果表明,TiH_(2)粉末具有较好的烧结活性,脱氢烧结样品的相对密度可达97.7%;经热挤压工艺,相对密度进一步提升到99.9%,接近于全致密。增强相TiB为短纤维状,TiC为颗粒状,均匀分布在等轴α-Ti基体中,能抑制等轴晶的长大,细化晶粒。热挤压工艺能进一步细化晶粒,使组织更加均匀致密,挤压态钛基复合材料具有高硬度和良好的强塑性匹配。TiH_(2)+4%B4C(体积分数)挤压态复合材料维氏硬度Hv0.3310,屈服强度683 MPa,抗拉强度851 MPa,断后伸长率15.1%。
Ti/(TiB+TiC)titanium matrix composites with the excellent mechanical properties were prepared by vacuum pressureless sintering and hot extrusion by using low-cost TiH_(2) powders instead of pure titanium powders and adding B4C to in-situ produce TiB and TiC reinforcements.The effects of preparation technology and reinforcements on the microstructure and properties of the Ti/(TiB+TiC)composites were analyzed.The results show that the TiH_(2) powders have the good sintering activity,and the relative density of the sample after dehydrogenation and sintering can reach 97.7%,which is further increased to 99.9%after the hot extrusion as closed to full density.The TiB reinforcements are short fibrous,and the TiC reinforcements are granular,which are uniformly distributed in the equiaxedα-Ti matrix,restraining the growth of equiaxed grains and refining the grains.The hot extrusion process can further refine the grains and make the microstructure more uniform and compact,the as-extruded titanium matrix composites show the high hardness and good matching of strength and ductility.The TiH_(2)+4%B4C(volume fraction)extruded composites have the Vickers hardness of Hv0.3310,yield strength of 683 MPa,tensile strength of 851 MPa,and elongation of 15.1%after fracture.
作者
林东键
柳中强
唐浩
张建涛
肖志瑜
LIN Dongjian;LIU Zhongqiang;TANG Hao;ZHANG Jiantao;XIAO Zhiyu(National Engineering Research of Net-Sharp Forming for Metallic Material,South China University of Technology,Guangzhou 510640,China)
出处
《粉末冶金技术》
CAS
CSCD
北大核心
2024年第2期135-143,共9页
Powder Metallurgy Technology
基金
国家自然科学基金资助项目(52274363)
广东省自然科学基金资助项目(2015A030312003)。
关键词
TiH2粉末
钛基复合材料
热挤压
显微组织
力学性能
TiH_(2)powders
titanium matrix composites
hot extrusion
microstructure
mechanical properties
