摘要
以WC、Ti C、Co和Co50合金粉末为原料,通过设计不同的成分配比,在40Cr刀具钢表面激光熔覆了WC/Co、WC/Co50和WC-Ti C/Co50钴基碳化物复合涂层。借助XRD、OM、SEM和EDS等表征手段分析了粉末成分配比和激光熔覆工艺参数对刀具表面复合涂层物相结构、宏观形貌和微观组织的影响。结果表明,当激光功率为4.2 k W,扫描速度为350 mm/min时,制备的WC/Co50和WC-Ti C/Co50复合涂层表面形貌良好,平整连续且无宏观裂纹。硬度测试和摩擦磨损试验表明,复合涂层具有高的硬度和良好的耐磨性,最高显微硬度达到1211 HV0.2,最低磨损失重2.1 mg,分别为基材的3.03倍和34.4%。熔覆层中大量存在的WC、Ti C以及原位自生的W2C、Fe3W3C等碳化物增强相对提高复合涂层的硬度和耐磨性起到了主要作用。
WC/Co, WC/Co50 and WC-TiC/Co50 carbide composite coatings are prepared by laser cladding process on 40Cr tool steel surface through designing different composition ratio of WC, TiC, Co and Co50 powder. The influence of laser cladding process parameters and powder composition ratio on the composite coating phase structure, macroscopic morphology and microstructure are investigated by X-ray diffraction （XRD）, optical microscope （OM）, scanning electron microscope （SEM） and energy dispersive spectrometer （EDS）, respectively. The results show that the WC/Co50 and WC-TiC/Co50 composite coatings surface morphology is good, smooth and without continuous macroscopic crack under the laser power of 4.2 kW and scanning speed of 350 mm. min-1 conditions. Hardness and friction wear tests indicate that the composite coating has high hardness and good wear resistance, the highest microhardness is 1211 HV02 and the minimum wear weight loss is 2.1 mg. The maximum microhardness and minimum wear weight loss is 3.03 times and 34.4% of the substrate, respectively. A lot of WC, TiC and in-situ W2C, FesWsC carbide reinforced phases play a major role on improving the cladding coating hardness and wear resistance.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2015年第11期45-50,共6页
Chinese Journal of Lasers
基金
国家自然科学基金(61368003
51165015)
