摘要
通过质量增加率的计算、扫描电镜观察和X射线衍射分析等,研究WC-8.4Co、WC-8.4Co-0.4Cr3C2、WC-8.4Co-0.4VC、WC-8.4Co-0.4TaC、WC-8.4Co-0.7Cr3C2、WC-8.4Co-0.7Mo2C、WC-8.4Co-0.4Cr3C2-0.05RE以及WC-8.4Co-0.4VC-0.05RE(RE为混合稀土)等8组超粗晶和特粗晶硬质合金在700℃连续氧化16 h的高温氧化行为。结果表明,VC、TaC和Mo2C的添加会降低合金的抗氧化性能;当添加量(质量分数,下同)达到0.7%时,Cr3C2才具有明显改善合金抗高温氧化性能的功能;而稀土的添加量仅为0.05%时即可明显改善合金抗高温氧化性能;添加剂可改变WC-Co合金表面CoWO4物相的生长行为,从而影响合金的抗高温氧化性能。
The oxidation behaviors of extra coarse and super extra coarse cemented carbides with different additives at the temperature of 700℃ for 16 h were investigated by a gravimetry method, scanning electron microscopy and XRD analyses. The analyzed alloys included WC-8.4Co, WC-8.4Co-0.4Cr3C2, WC-8.4Co-0.4VC, WC-8.4Co-0.4TaC, WC- 8.4Co-0.7Cr3C2, WC-8.4Co-0.7Mo2C, WC-8.4Co-0.4Cr3C2-0.05RE and WC-8.4Co-0.4VC-0.05RE （RE： mischmetal）. It is shown that the addition of VC, TaC and MoeC degrades the oxidation resistance of alloys. The function of significant improvement for the high-temperature oxidation resistance of Cr3C2 additive can be realized on the condition that the addition amount reaches 0.7%. While the addition amount is as small as 0.05%, rare earth in the alloys demonstrates a strong ability in the improvement of the high-temperature oxidation resistance. The additives can change the growth behaviors of CoWO4 phase formed on the surfaces of WC-Co alloys, thus affecting the resistance to high temperature oxidation.
出处
《粉末冶金材料科学与工程》
EI
北大核心
2015年第4期595-602,共8页
Materials Science and Engineering of Powder Metallurgy
基金
硬质合金国家重点实验室开放基金资助项目(201403002)
国家自然科学基金资助项目(51074189)
国家科技支撑计划资助项目(2013BAF07B06)
关键词
硬质合金
过渡族金属碳化物
稀土
高温性能
氧化行为
特粗晶
cemented carbide
transitional metal carbide
rare earth
high-temperature property
oxidation behavior
super extra coarse grain
