冷喷涂金属涂层的耐腐蚀性能的提升方法

沉积温度低的特点使冷喷涂可避免喷涂金属粉末的氧化及对基材的热影响，是制备高致密金属涂层的有效 方法，在耐腐蚀金属涂层制备方面具有广阔的应用前景。然而在粒子高速碰撞沉积过程中，容易因粒子的塑性变 形程度不足而在粒子界面形成孔隙，相互连通的孔隙导致涂层不能隔绝腐蚀介质的渗入，因此不具备长效腐蚀防 护作用。对此，本文首先介绍了冷喷涂金属涂层的显微组织特点；其次，重点从基于热作用、力作用和热力耦合 作用的原位处理或后处理总结了改善冷喷涂金属涂层内部粒子间结合质量，进而提升金属涂层耐腐蚀性能的方法， 包括原位喷丸辅助冷喷涂方法、热处理、激光重熔、搅拌摩擦处理与热轧处理等，最后，针对当前冷喷涂耐腐蚀 涂层的发展现状，总结了亟待解决的问题和发展方向。

Approaches to Improve the Corrosion Protection Performance of Cold Sprayed Metallic Coatings

Because of the low deposition temperature, cold spraying is capable to avoid the oxidation of sprayed metal powder and the excessive heat effect on the substrate. It is an effective method to prepare high-density metal coatings, and has broad application prospects in preparing corrosion-resistant metal coatings. However, during the high velocity particle impact process, pores are easily formed at the particle interface due to the insufficient plastic deformation of particles. The interconnected pores makes the cold sprayed coating cannot prevent the infiltration of corrosive media, so it usually cannot provide long-term corrosion protection. The microstructure characteristics of cold-sprayed metal coating were briefly introduced. The approaches on improving the bonding quality between particles in the cold sprayed metallic coating and improving the corrosion resistance of the metal coating were summarized mainly from three in-situ treatments and posttreatments based on thermal-based treatments, mechanical-based treatments and thermal-mechanical coupled treatments. The in situ treatments were discussed in terms of in-situ shot peening assisted cold spraying method, in-situ laser assisted cold spray and the post-spray treatments were introduced as heat treatment, laser remelting, friction stir treatment and hot rolling treatment. Finally, according to the current development status of cold sprayed corrosion-resistant coating, the problems to be solved and the development direction were summarized.