Plasma Sprayed NiA1 Intermetallic Coating Produced with Mechanically Alloyed Powder

• 来源期刊: 材料科学技术学报：英文版
• 学科: 工学
• 关键词: 金属间化合物相 等离子喷涂 机械合金化 粉末涂层 热处理温度 扫描电子显微镜 硬度测量 喷涂距离
• 年，卷（期）: 2011,（9）
• 页码范围: 816-820
• 页数: 5页
• 分类号: TG146.21|TG174.442
• 语种: 英文

摘要

In the present research, mechanically alloyed Ni-AI powder was utilized to develop plasma sprayed coatings, and the effect of the spray distance and heat treatment on the phases, microstructure, and hardness of the coat- ings were examined. Coatings were analyzed by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, energy-dispersive spectroscopy （EDS） and through microhardness measurements. Although mechanically alloyed Ni-AI powder showed no intermetallic phases, the coatings did. Different spray distances from 5 to 19 cm were employed for plasma spray and the specimens were heat treated at different temperatures, then the amount of oxides, porosity and hardness of the coatings were changed according to the spray condition. The thermal energy of the plasma spray caused the formation of NiAI phases while particles flew to the substrate or after that. Extreme increase in heat treatment temperature and spray distance resulted in oxidation and reduction in the quality of the coating. Furthermore, the best spray distance and heat treatment temperature to gain the NiAI intermetallic coating were established.