热喷涂基体表面前处理技术的研究进展

热喷涂涂层与基体机械咬合的结合机理决定了基体表面前处理是热喷涂涂层中非常重要的处理工艺。文中概述了当前广泛应用的喷砂处理的工艺特点,指出砂粒易在基体表面镶嵌和对基体造成损伤是喷砂工艺的主要缺点,讨论了喷砂对高温合金单晶材料和超高强钢疲劳性能的影响,研究了软质基体表面超音速火焰喷涂WC涂层的免喷砂工艺。同时介绍了近年来其他热喷涂基体表面前处理方面的研究热点,包括高压水射流处理技术、机械粗化技术以及激光表面前处理,并重点阐述了其基本原理、特点及应用情况。

Review on the Pretreatment of Substrate for Thermal Spray Process

Pretreatment on substrate was extremely important as a result of the bond strength of mechanical occlusion between coating and substrate. The technical characteristics of currently and widely used grit blasting were reviewed, and the two main drawbacks including grit embedment and damage to substrate for the grit blasting process were pointed out. The effects of grit blasting on high temperature single crystal substrate and ultra high strength steel were discussed. Free grit blasting treatment was recommended for the deposition of HVOF WC coating on relatively soft substrate. Meanwhile, the current research focus on other pretreatment processes on substrate, including high pressure water jet, mechanical roughening and laser treatment was introduced. The principle of the process, process characteristics and their applications in the pretreatment of thermal spray process were emphasized in the introductions to these processes.