用电热爆炸超高速喷涂法制备WC-Co合金涂层的研究

制备高性能表面耐磨涂层是抵抗工件磨损的有效途径.利用自行研制的电热爆炸超高速喷涂装置,进行了在大气环境下制备WC-Co硬质合金抗磨涂层的试验研究.分析了WC-Co金属陶瓷箔爆炸过程的电学变化特性,不同电压等级下的试验结果表明:爆炸箔的平均能量利用率约为30%,得到了亚微米级的超细晶涂层;涂层的平均显微硬度为原始喷涂材料硬度的1.1～1.5倍,最高可达2 220 HV;在涂层与基体结合面处形成了不同于涂层和基体组织的过渡层;晶粒直径最小可达70 nm,平均晶粒度级别数G=20.8.

Preparation of WC-Co Alloy Coating by Electrothermal Explosion Ultrahigh Velocity Spraying

Preparation of surface coating with high wear resistance is an efficient path to prevent abrasion of workpiece. Experimental study was carried on to prepare antiwear coating of ultrafine crystalline WC-Co hard alloy in atmosphere environment by using self-made electrothermal explosion ultrahigh velocity spraying device. The electric characteristics during the electrothermal explosion were analyzed in detail, and the microstructure and microhardness of coating were measured. Experimental results at different initial voltage show that the average energy usage ratio of metal foils is about 30%, the average microhardness of WC-Co coatings is 1.1~1.5 times of the original material, and the maximum is up to 2 220 HV. A transition layer with different microstructure is formed on the interface of coating and substrate. The minimum crystal diameter reaches 70 nm, and the average crystalline degree grade is 20.8.