摘要
研究了WC-8%Co硬质合金的粉末注射成形工艺,考查了不同气氛和脱脂方法对脱脂坯碳含量的影响及烧结温度、保温时间对合金强度的影响,以及固体粉末装载量对产品尺寸精度及保形性的影响。结果表明:溶剂脱脂+75%N2/25%H2混合气体热脱脂工艺,不仅能大幅度提高脱脂速率,而且有利于合金碳含量的控制。提高试样固体粉末装载率有利于提高制品密度和尺寸精度。在1460℃烧结,保温2h,PIM硬质合金试样的抗弯强度、硬度、密度分别达到2480MPa,HRA900MPa,和14.72g.cm-3;烧结后制品保形性良好,尺寸偏差为±0.02mm;断口检查和金相检验没有发现任何明显缺陷,合金组织均匀;平均晶粒度为2μm,孔隙度为A02B00,无石墨夹杂和η相出现。
The powder injection mol ding of WC-8% Co tungsten cemented carbide was investigated. The results showed that the two step debinding method( solvent debinding plus subsequent thermal debinding in a 75%N(2)/25%H(2) atmosphere) would not only greatly shorten debinding time, but also be convenient for carbon control; High powder loading would benefit dimension precision and shape retention; Specimens sintered at 1 460degreesC for 2 h became two phase and exhibited transverse rupture strength, hardness, coercivity and density of 2 480 MPa, HRA900MPa, 8.95 kA (.) m(-1) and 14.72 g (.) cm(-3), respectively. The average grain size was 2mum and the void ratio was less than 0.02%. No carbon interspersion and eta phase appeared. Good shape retention coupled with only 0.02% dimension deviation were achieved.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2002年第4期303-307,共5页
Rare Metal Materials and Engineering
基金
国家杰出青年科学基金(50025412)
国家重点基础研究发展规划资助课题(G2000067203)
关键词
粉末注射成形
硬质合金
碳含量
尺寸精度
力学性能
powder injection molding
tungsten cemented carbides
carbon content
mechanical property
dimension precision
