低压等离子喷涂ZrB_2-SiC复合涂层烧蚀机理研究  

The Research on Ablation Mechanism of ZrB_2-SiC Coating Prepared by Low Pressure Plasma Spraying(LPPS)

作　　者：文波[1] 马康智 倪立勇[1] 杨震晓[1] 杨杰[1] 吴朝军[1] WEN Bo;MA Kang-zhi;NI Li-yong;YANG Zheng-xiao;YANG Jie;WU Chao-jun(Aerospace Materials and Technology Research Institute,Beijing 100076,China)

机构地区：[1]航天材料及工艺研究所,北京100076

出　　处：《热喷涂技术》2016年第3期30-35,共6页Thermal Spray Technology

摘　　要：采用喷雾干燥制备出适用于低压等离子喷涂的ZrB2-SiC复合粉体，采用低压等离子喷涂可在石墨基体表面制备ZrB2-SiC复合涂层，研究了粉体和所制备的涂层组织形貌、相结构及烧蚀防护机理。结果表明：ZrB2-SiC复合粉体呈现良好球形，粒度介于20～50μm，流动性可达28s/50g；所制备的涂层呈现典型的等离子喷涂特征，涂层孔隙率为6.8%，结合强度达10.3MPa，物相与粉体一致；涂层经等离子弧烧蚀后呈现三种不同形貌区域，其中，中心高温区呈现ZrO2熔化再结晶形貌，过渡中温区由于熔融的SiO2有效填充涂层表面缺陷而呈现致密平整结构，边缘低温区因B2O3、SiO2熔融量不足无法填充缺陷而较多地保留喷涂态形貌。The ZrB2-SiC composite powder used in LPPS was prepared by spray-drying,and the ZrB2-SiCcomposite coating was deposited by LPPS on the graphite matrix.The microstructure,phase structure and ablationmechanism of ZrB2-SiC powder and coating were studied.The results indicated that the ZrB2-SiC compositepowders showed good spherical,and their granularity and liquidity were20～50μm and28s/50g,respectively.The coating prepared by LPPS presents a typical plasma spraying coating,its porosity is6.8%and bondingstrength is up to10.3MPa.The coating keeps the same phase structure with powder.Coating ablated by plasmaarc presents three different ablation areas.In the high temperature center zone,ZrO2presents melting and recrystallizationmorphology.In the medium temperature transition zones,the molten SiO2can filling the coatingsurface defects effectively and the surface of coating presents a dense and smooth structure.In the low temperatureedge zone,the coating surface still show plasma spraying original morphology because of the insufficient SiO2andB2O3,which can melt and fill the defect.

关 键 词：喷雾造粒 低压等离子喷涂 ZrB2-SiC复合涂层 烧蚀机理 

分 类 号：TG174.4[金属学及工艺—金属表面处理]