湿法制备W-1%TiC纳米复合粉末的烧结致密化及其合金组织与力学性能  

Densification behavior of W-1%TiC nanometer composite powder prepared by a wet method and microstructure and mechanical property of its alloys

作　　者：章曼[1] 范景莲[1] 李鹏飞[1] 韩勇[1] ZHANG Man;FAN Jinglian;LI Pengfei;HAN Yong(State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China)

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083

出　　处：《粉末冶金材料科学与工程》2017年第5期668-673,共6页Materials Science and Engineering of Powder Metallurgy

基　　金：国家自然科学基金重点项目(51534009);国家自然科学基金面上项目(51474242);国家磁约束核聚变能发展研究专项(2014GB115001)

摘　　要：用偏钨酸铵和纳米TiC粉末为原料,采用溶胶–喷雾干燥–氢还原法制备W-1%TiC复合粉末,并将粉末进行模压成形和氢气气氛高温烧结,得到微量TiC弥散强化细晶钨合金,研究W-1%TiC复合粉末的烧结致密化行为,以及不同烧结温度下所得合金的组织与室温力学性能。结果表明,采用溶胶–喷雾干燥–氢还原法制备的W-1%TiC复合粉末,其BET粒径约为50 nm,氧含量为0.24%,TiC颗粒均匀分散在W颗粒中。制备的纳米W-1%TiC复合粉末具有较高的烧结活性,粉末在1 920℃烧结后,相对密度达到99.5%,钨晶粒尺寸约为4μm,TiC颗粒尺寸非常细小(0.2~0.5μm),合金抗拉强度达到426 MPa,比纯钨高约1倍。W-1%TiC composite powders were prepared by sol,spry drying and hydrogen reduction method using partial ammonium tungstate and nano-sized TiC powders as raw materials.The trace titanium carbide strengthened fine-grain tungsten alloys were fabricated by cold pressing the W-1%TiC composite powder and then sintering at high temperature in hydrogen atmosphere.The sintering densification behavior of the W-1%TiC composite powders,microstructure and mechanical properties of W-1%TiC alloys sintered at different temperatures were studied.The results show that the composite powders prepared by sol,spry drying and hydrogen reduction method are nano powders with an average BET particle size of50nm and oxygen content of0.24%.The TiC particles disperse evenly between W particles.W-1%TiC composite powders have high sintering activity and highest relative density of W-1%TiC alloy obtained at1920℃(95%).The addition of1%TiC particle can inhibit the grain growth of tungsten,and the average particle size of W and TiC in W-%TiC alloy is4μm and0.2?0.5μm,respectively.The tensile strength of the W-1%TiC alloy reaches426MPa which is2times higher than that of pure tungsten.

关 键 词：纳米W-TiC复合粉末 致密化行为 微观组织 力学性能 

分 类 号：TG146.4[一般工业技术—材料科学与工程]