等离子制备高铝青铜合金粉体涂层的组织及其性能

Structure and property of high aluminum bronze coating sprayed with plasma melt-coating

为解决模具关键部位更换铝青铜垫块的加工、更换困难和铝青铜模具脆性大的问题,通过气体水雾化法制备Cu-14Al-X高铝青铜合金粉末,用等离子热喷涂制备涂层.用X射线衍射分析、往复式摩擦实验、扫描电镜、电子探针等方法研究Cu-14Al-X合金等离子涂层组织、结合强度和摩擦磨损性能.结果表明,涂层与基材为冶金结合,组织为β+γ+Κ,硬度达372 HV,试样在实际工况相当参数(压力15.6 MPa,滑动速度0.2 m/s)下与304不锈钢干摩擦对磨,摩擦系数为0.08.等离子涂层具有良好的减摩性和耐磨性,满足静态挤压模具工作要求.

The expense on machining aluminum bronze blocks and inserting them into key spot of dies and the failure caused by brittleness of such block could be avoided by preparation of water-atomized Cu-14Al- X bronze powder in inert gas shielding to form coating film with plasma spraying. X-ray diffraction, scanning electron microscopy, X-ray photo-electron spectroscopy and electron probe micro-analysis were carried out to investigate the microstructure, bonding strength and wear/friction properties of the coating film. The result showed that there was a metallurgical bonding between coating film and matrix metal, the structure of the coating film was consist of β＋γ＋K phases with hardness of 372 HV. By using test regime similar to actual one in practice （sliding velocity being 0. 2 m/s and load-15. 6 MPa）, the coating exhibited a friction coefficient of 0.08 during unlubricated friction onto 304 stainless steel. With excellent anti-frication property and high wear-resistance, the plasma sprayed coatings with Cu-14Al-X met the case of static operation of extrusion dies.