WC与Mo2C的添加对Ti(C,N)基金属陶瓷显微组织和耐腐蚀性能的影响

目的 研究Ti(C,N)-WC-Mo2C-Ni-Co金属陶瓷的成分、显微组织和耐腐蚀性能之间的关系,以期提高金属陶瓷材料的耐腐蚀性能.方法 采用粉末冶金方法 在金属陶瓷中添加不同比例的WC与Mo2C,并对金属陶瓷显微组织、力学性能及在酸性和碱性溶液中的腐蚀行为进行系统研究.结果 随着WC与Mo2C比例的降低,金属陶瓷组织中黑芯-灰环硬质相增多,白芯-灰环硬质相减少,环形相的厚度增加,材料的硬度先升高后下降,断裂韧性先下降后升高.当w(WC)/w(Mo2C)为0︰3时,金属陶瓷的硬度、断裂韧性和抗弯强度分别为90.5HRA,12.12 MPa·m1/2和2030 MPa.金属陶瓷在硫酸溶液中,较低的Mo2C添加量可以改善金属陶瓷的耐腐蚀性能.当w(WC)/w(Mo2C)为2︰1时,材料在硫酸溶液中有较好的耐腐蚀性能.在KOH溶液中,Mo2C添加量的提高会使材料在KOH溶液中的耐腐蚀性能降低.结论 对于设计和制备应用于不同腐蚀环境下的金属陶瓷材料有较好的指导意义,可以有效拓宽金属陶瓷的应用领域.

Effect of WC and Mo2C Additions on Microstructure and Corrosion Resistance of Ti(C,N)-Based Cermet

The work aims to investigate the relationship among the composition, microstructure and corrosion resistance of Ti(C,N)-WC-Mo2C-Ni-Co cermet to improve the corrosion resistance of cermet. Cermets with different WC/Mo2C ratio were prepared by powder metallurgy methods. The microstructure, mechanical properties and corrosion behaviors in acid and alkaline solution were investigated systematically. The results showed that the decrease of w(WC)/w(Mo2C) caused the increase of black core-gray rim structure, the decrease of white core-gray rim structure and the increase of rim phase thickness. The hardness of cermet initially firstly increased and then decreased. The fracture toughness of cermet firstly decreased and then increased. When w(WC)/w(Mo2C) was 0:3, the hardness, fracture toughness and transverse rupture strength of cermet were 90.5HRA, 12.12 MPa.m1/2 and 2030 MPa, respectively. In H2SO4 solution, a small quantity of Mo2C additions could enhance the corrosion resistance of cermet. When w(WC)/w(Mo2C) was 2:1, the cermet had excellent corrosion resistance in H2SO4 solution. However, the increasing Mo2C additions had a negative effect on the corrosion resistance of cermet in KOH solution. The investigation results provide the guiding significance for the design and preparation of cermets applied in the different corrosion environment, and broaden the application fields of cermet.