含碳量对WC-13Co硬质合金组织和性能的影响

Effects of Carbon Content on Microstructure and Property of WC-13Co Cemented Carbide

采用粉末冶金方法制备了不同碳含量的WC-13Co细晶粒硬质合金。采用X射线衍射、SEM、自动钴磁仪、矫顽磁力测量仪等分析方法,研究了含碳量对细晶粒WC-13Co硬质合金表面组织及性能的影响。结果表明,随着含碳量的增加,合金中石墨相逐渐增多,WC颗粒长大;烧结后含0.2%C的WC-13Co硬质合金只存在(WC+γ)相,抗弯强度达到最大值3 730 MPa,断口中存在很多韧窝;随着碳含量的增加,合金的硬度下降,矫顽磁力降低,而磁性钴含量不断升高,但均小于原始钴含量。

Fine-grained WC-13Co cemented carbides with different carbon contents were prepared by a powder metallurgy method. The effect of the carbon contents on the microstructure and property of the fine-grained WC- 13Co cemented carbide were investigated by XRD, SEM, automatic cobalt magnetometer and coercimeter. The results showed that as the carbon content increased, graphite phase in the cemented carbide increased, and the WC grains became larger, After being sintered, the cemented carbide having 0.2% C presented only （ WC ＋ γ） phase, and exhibited as maximum bending strength as 3 730 MPa and fracture in which there are lot of dimples. With the increase of carbon content, the hardness and coercive force decreased, and the content of magnetic cobalt increased but was less than the original cobalt content for the that WC-13Co cemented carbide.