PCrNi3MoVA钢表面微弧沉积Stellite6合金涂层研究

采用微弧沉积工艺,以Stellite6合金焊棒为沉积材料,在PCr Ni3Mo VA钢基体上多次沉积形成合金涂层,对涂层的形貌、元素组成、相组成、显微硬度和抗烧蚀性能进行了检测。结果表明:涂层与基体之间形成了良好的冶金结合,涂层致密,孔隙少,具有较好的耐磨性能和抗烧蚀性能。

In vitro corrosion resistance of a Ta2O5 nanofilm on MAO coated magnesium alloy AZ31 by atomic layer deposition

Micro-arc oxidation(MAO)coating with outstanding adhesion strength to Mg alloys has attracted more and more attention.However,owing to the porous structure,aggressive ions easily invaded the MAO/substrate interface through the through pores,limiting long-term corrosion resistance.Therefore,a dense and biocompatible tantalum oxide(Ta2O5)nanofilm was deposited on MAO coated Mg alloy AZ31 through atomic layer deposition(ALD)technique to seal the micropores and regulate the degradation rate.Surface micrography,chemical compositions and crystallographic structure were characterized using FE-SEM,EDS,XPS and XRD.The corrosion resistance of all samples was evaluated through electrochemical and hydrogen evolution tests.Results revealed that the Ta2O5 film mainly existed in the form of amorphousness.Moreover,uniform deposition of Ta2O5 film and effective sealing of micropores and microcracks in MAO coating were achieved.The current density(icorr)of the composite coating decreased three orders of magnitude than that of the substrate and MAO coating,improving corrosion resistance.Besides,the formation and corrosion resistance mechanisms of the composite coating were proposed.

TC11钛合金表面微弧沉积碳化钨涂层及耐烧蚀性能研究

考虑到钛合金导热系数较小,在不同温度下以WC为沉积材料,采用微弧沉积技术在TC11钛合金表面制备耐烧蚀涂层。分析了涂层的SEM微观形貌、显微硬度,利用摩擦磨损仪测试了涂层的磨损率;以某型大口径火炮实验平台模拟了发射状态下身管内膛工况条件,检测了涂层的耐烧蚀性能。结果表明:在200℃下将钛合金圆片预热2 h且沉积涂层后保温2 h条件下所制备的涂层外观形貌无裂纹,且涂层均匀致密、硬度高,耐烧蚀性能明显优于传统的炮钢材料。