电冶熔铸WC-Co/钢复合材料组织和性能的研究

Microstructure and Properties of WC-Co/steel Matrix Composites by Electroslag Melting and Casting

用回收的废WC Co硬质合金作原料,采用电冶熔铸法制备了新型的WC/钢基复合材料。借助金相分析、扫描电镜及X射线衍射等方法研究了该材料铸造原始态和退火态的微观组织结构,还测试了主要力学性能。材料中的硬质相和钢基体相的相互溶解,使两相实现了冶金结合,形成含W和Co的碳化物,但形态不佳。增加电磁搅拌可使枝晶"破碎";经退火处理和锻造可以改善材料中的不良组织,使硬质相碳化物粒子均匀地分布在钢基体中,冲击韧度也得到提高。

A new kind of WC/steel matrix composites was prepared by electroslag melting and casting and by utilizing waste WC-Co cemented carbides as raw material. As-cast and as-annealed and as-forged microstructures of this material were studied by means of opical microscopy and SEM and X-ray diffraction anlysis, and main mechanical properties were measured. The results show that hard phases and steel matrix phase in the material can solute each other and it results in these phases metallurgical combine and forming carbides which contain W and Co but have improper shape. The electromagnetic stirring has the action of cracking dendrites; annealing and forging help improve the improper structures, and It results in hard phases carbides particles distributing uniformly in steel matrix and impact toughness increasing.