摘要
以Co、Ni为粘结剂,按照m（Co）∶m（Ni）=6∶1,通过混合、冷等静压烧结,制备了93W-Co-Ni高硬度钨合金。研究了烧结温度对合金密度、显微组织的影响,分析了烧结过程中合金HRC硬度的变化趋势与原因。结果表明：随着烧结温度升高,合金密度增加,在1 605℃时,密度达17.73 g·cm-3,致密化程度为99.16%；随着烧结温度升高,W晶粒逐渐长大、球化,最后W晶粒平均粒径为20.91μm,符合粉末冶金烧结原理；在烧结过程中,合金硬度先降低而后趋于稳定,稳定时其HRC硬度在41～42之间,合金硬度的显著提高与W晶粒细化、形成金属间化合物Co7W6有关。
93W-Co-Ni tungsten heavy alloys with high hardness were prepared by compositing,cold isostatic pressing and sintering with m（ Co） ∶ m（ Ni） ratio of 6∶ 1. The influence of sintering temperature on density and microstructure was investigated,the change of HRC hardness in sintering process was studied,and the cause of hardness increasing was analysed. The results show that with increasing sintering temperature,the density increases,the density reaches the value of 17. 73 g · cm-3and the relative density reaches 99. 16% by sintering at 1 605 ℃. With increasing sintering temperature,the tungsten crystal grains grow and get smooth,at last the average grain size is about 20. 91μm,which accords with sintering mechanism of powder metallurgy. In the sintering process,the HRC hardness of alloy first reduces and then tends to stabilization in the range of 41 ～ 42. The smaller tungsten crystal grains and formation of intermetallic phase Co7W6result in the increase of hardness.
出处
《粉末冶金技术》
CAS
CSCD
北大核心
2014年第2期83-86,共4页
Powder Metallurgy Technology
基金
西安市科技局企业技术创新工程资助项目(CX1266)
关键词
Co/Ni比
高硬度
钨合金
密度
晶粒
Co/Ni ratio
high hardness
tungsten heavy alloy
density
crystal grain
