热喷涂铜基W涂层工艺性能研究

Study on high velocity oxy-fuel and plasma spraying process of W coatings on copper substrate

采用超音速火焰(HVOF)和等离子喷涂工艺制备铜基体W涂层,分析涂层的组织形貌,测定等离子喷涂W涂层的孔隙率、显微硬度和结合强度,并考察该涂层的压缩性能。结果表明:HVOF制备W涂层时,钨颗粒加热熔化不充分,主要以固态颗粒形式撞击基体,不能形成连续涂层;等离子喷涂W涂层时,钨颗粒熔化充分,铺展变形改善,涂层致密,平均孔隙率为2%,显微硬度为315HV0.1;等离子喷涂W涂层与铜基体结合质量较好,结合强度可达36MPa,经压缩变形后与铜基体结合较好,涂层未出现整体剥落,二者具有较好的协调变形能力,随压缩载荷增加,涂层和基体变形量差值增大,涂层边角部分孔隙增加,结合能力变差。

W coatings were prepared on copper substrate by means of high velocity oxy-fuel （HVOF）and plasma spraying in this paper. Morphologies, porosity and micro-hardness of W coatings were investigated. Compression and tensile performance were tested. The results show that W particles melt insufficiently and impact the copper substrate in the form of solid particles, so the W coating is discrete in the HVOF spraying. However, W particles melt better and deform perfectly in the plasma spraying. The plasma spray W coating is compact with the porosity of 2 percent and the micro-hardness of 315HV under the press of 100 gramme. The adhesion between copper substrate and plasma spray W coating is good and the strength can reach near 36MPa. W coating doesn＇t separate from the copper substrate after compression test. The deformation difference between copper substrate and W coating and porosity in the brim of the coating increase with the increase of compression stress.