低压电弧喷涂涂层组织及其后处理工艺

Study on microstructure of the coatings sprayed in low pressure condition and its post-treatment technology

采用4Cr13、铝和钛喷涂丝材分别在大气环境和低度真空环境中制备了喷涂层.通过金相组织分析和定点成分分析对比了涂层的组织形态、化合物的数量及分布状态;并通过加压试验分析了涂层在压力作用下,涂层内部孔隙弥合的情况;最后通过加热使涂层组织中发生再结晶,研究了再结晶处理对涂层组织的影响.结果表明,低压电弧喷涂可以有效地减少4Cr13和铝涂层中的氧化物数量,且通过加压及再结晶处理可以使涂层粒子间形成冶金结合.但对于钛涂层,所提供的低压喷涂环境还不能提供很有效的防护,再结晶处理也无法获得粒子间良好的冶金结合.

In order to make clear the effect of the spraying technology on the coatings microstructure formation in the low pressure spraying,the wires of 4Cr13,Al and Ti were adopted to prepare the spraying coatings in air and low pressure condition,respectively.The microstructure,the amount of the compounds and their distribution pattern in both coatings were compared by the micro-analysis and microarea chemical analysis.Static press test was used to investigate the closing possibility of the porosities.After the press test,the coatings was heated to certain temperature to analyze the effect of the recrystallization heat treatment on the coatings microstructure.As a result,the amount of the oxide in 4Cr13 and Al coatings has been reduced obviously in the low pressure condition,and metallurgy combination between the splat particles can be formed by pressing and heating.However the low pressure condition can not provide sufficient protection for the Ti coatings,the following recrystallization heat treatment can not get metallurgy combination between the particles.