纳米钨粉坯的低温固相烧结特征  

Low Temperature Solid Phase Sintering of Nanoscaled Tungsten Powder

作　　者：林涛[1] 张丽英 赵放[1] 李会谦[1] 吴成义[1] 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083

出　　处：《机械工程材料》2006年第5期91-94,共4页Materials For Mechanical Engineering

基　　金：教育部科学技术研究资助项目(105015);家863计划资助项目(2002AA331090)

摘　　要：用高压软模成形法将纳米钨粉和常规钨粉制成压坯,测定了两种压坯在H2中的烧结收缩动力学曲线;研究真空烧结时烧结温度与烧结密度的关系,用SEM和定量金相研究了烧结后的组织。结果表明:纳米钨粉坯在H2中烧结时开始收缩温度为250℃,450～1 450℃收缩速率较快,最大值在1 200℃;1 500℃×20 min烧结的相对密度可达96．4％。在真空中l 500℃x 20 min烧结时,相对密度可达96．7％,合金平均粒径为5．8μm。常规钨粉坯在H2中烧结时于1 400℃开始收缩,1 500℃烧结相对密度为66．2％;2 250℃真空烧结的相对密度为96．9％,但平均晶粒尺寸为223μm。After compacted with a rubber die, the traditional tungsten powders and nanoscaled tungsten powders were sintered in order to investigate the shrinkage kinetic curves in hydrogen and study the relationship between the sintered density and sintering temperature in a high-temperature dilatometer. After sintered , the microstructure of the compacts were examined by SEM. The compact of nanoscaled tungsten powders started to shink at 250 ℃. The shrinkage rate became fast from 450 ℃ to 1 450 ℃ and the temperature corresponding to the highest shrinkage rate of nanoscaled tungsten powders was 1 200 ℃. The relative density of sintered sample in 1 500 ℃ × 20 min was 96. 4%, but when sintered in vacuum, the relative density was 96. 7% and the grain size was about 5. 8 μm The compact of traditional tungsten powders started to shrink at 1 400 ℃. After sintered at 1 500 ℃, the sample had a relative density of 66. 2% ;When sintered in vacuum at 2 250 ℃, the relative density was 96. 9%, the averge grain size was 223 μm.

关 键 词：纳米钨粉 收缩动力学 烧结 

分 类 号：TB383[一般工业技术—材料科学与工程] TF124.5[冶金工程—粉末冶金]