PTFE掺杂对三价铬复合涂层的组织和力学性能的影响

Influence of PTFE additon on micro-structure and mechanical properties of Cr3+ composite coating

在电镀三价铬过程中掺杂不同量的PTFE(聚四氟乙烯),形成三价铬复合涂层,研究了不同浓度的PTFE粒子对三价铬复合涂层的组织和力学性能的影响。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、能谱仪(EDS)、纳米压痕仪和摩擦磨损试验机分别对三价铬涂层的微观结构和力学性能进行表征和测试,结果表明,不同浓度的PTFE对三价铬复合涂层的微观结构和力学性能影响显著。当镀液中PTFE掺杂量为12.5 mL/L、电流密度为35 A/dm^2、pH值约为2.0、温度为45℃、沉积时间为20 min时,所得三价铬复合涂层具有最佳的综合性能,硬度达到6.8 GPa,摩擦系数为最低值0.28。

Different amounts of PTFE were doped in the process of Cr^3+ electroplating to form Cr^3+ composite coating. The effects of PTFE particles with different concentrations on the micro-structure and mechanical properties of Cr^3+ composite coating were studied in this paper. The micro-structure and mechanical properties of Cr^3+ coating were characterized and tested by X-ray diffraction(XRD), scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS), nano-indenter and friction wear testing machine, respectively. The results show that different concentrations of PTFE had significant effects on the micro-structures and mechanical properties of Cr^3+ composite coatings. When the concentration of PTFE in the plating solution was 12.5 mL/L, the current density was 35 A/dm^2, the pH was about 2.0, the temperature was 45 ℃, and the deposition time was 20 min, the obtained Cr^3+ composite coating had the best comprehensive performance, with the hardness of 6.8 GPa and the lowest friction coefficient value of 0.28.