低成本TiH2粉末制备Ti/(TiB+TiC)复合材料的组织与性能
Microstructure and properties of Ti/(TiB+TiC)composites prepared by low-cost TiH2 powders
林东键 1柳中强 1唐浩 1张建涛 1肖志瑜1
作者信息
- 1. 华南理工大学国家金属近净成形工程技术研究中心,广州 510640
- 折叠
摘要
使用低成本的TiH2 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,TiH2 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.TiH2+4%B4C(体积分数)挤压态复合材料维氏硬度Hv0.3 310,屈服强度683 MPa,抗拉强度851 MPa,断后伸长率15.1%.
Abstract
Ti/(TiB+TiC)titanium matrix composites with the excellent mechanical properties were prepared by vacuum pressureless sintering and hot extrusion by using low-cost TiH2 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 TiH2 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 equiaxed α-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 TiH2+4%B4C(volume fraction)extruded composites have the Vickers hardness of Hv0.3 310,yield strength of 683 MPa,tensile strength of 851 MPa,and elongation of 15.1%after fracture.
关键词
TiH2粉末/钛基复合材料/热挤压/显微组织/力学性能Key words
TiH2 powders/titanium matrix composites/hot extrusion/microstructure/mechanical properties引用本文复制引用
基金项目
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)
出版年
2024
国家科技期刊平台
NSTL
万方数据