无金属粘结相硬质合金的电化学腐蚀行为

采用1 700℃、20 MPa高温高压固相烧结工艺制备WC-0.5Cr3C2-0.3VC、WC-3.65TiC-2.45TaC-0.47Cr3C2-0.28VC和WC-6Mo2C-0.47Cr3C2-0.28VC等3种无金属粘结相硬质合金。采用CHI 660C电化学工作站研究在pH=1的H2SO4溶液、pH=7的Na2SO4溶液和pH=13的NaOH溶液中3种合金的电化学腐蚀行为。结果表明,在pH=1的H2SO4溶液和pH=7的Na2SO4溶液中WC-6Mo2C-0.47Cr3C2-0.28VC合金的耐腐蚀性能最好,在pH=13的NaOH溶液中WC-3.65TiC-2.45TaC-0.47Cr3C2-0.28VC的耐腐蚀性能最好。3种无金属粘结相硬质合金在pH=13的NaOH溶液中的耐腐蚀性能均优于其在pH=1的H2SO4溶液中的耐腐蚀性能。综合比较合金的硬度、耐腐蚀性能以及原材料价格,3种合金中WC-6Mo2C-0.47Cr3C2-0.28VC合金具有更佳的性价比。

Electrochemical corrosion behaviors of binderless carbides

The WC-0.5Cr3C2-0.3VC,WC-3.65TiC-2.45TaC-0.47Cr3C2-0.28VC and WC-6Mo2C-0.47Cr3C2-0.28VC binderless carbides were prepared by solid phase sintering at the temperature of 1 700 ℃ and pressure of 20 MPa.Electrochemical corrosion behaviors were investigated in H2SO4 solution(pH=1),Na2SO4 solution(pH=7) and NaOH solution(pH=13).The results show that,WC-6Mo2C-0.47Cr3C2-0.28VC alloy exhibits the best corrosion resistance in H2SO4 solution(pH=1) and Na2SO4 solution(pH=7);while,WC-3.65TiC-2.45TaC-0.47Cr3C2-0.28VC alloy exhibits the best corrosion resistance in NaOH solution(pH=13).All the three alloys exhibit better corrosion resistance in NaOH solution(pH=13) than that in H2SO4 solution(pH=1).Considering the hardness,corrosion resistance and the cost of the raw materials of the alloys,WC-6Mo2C-0.47Cr3C2-0.28VC alloy is characterized with a higher performance price ratio among all the three alloys.