激光控制反应合成Ni/Al金属间化合物涂层的研究

用大功率CO2激光器在铸钢基体上反应合成了Ni／Al金属间化合物涂层。用扫描电镜、X射线衍射仪分析了涂层的组织和相组成，并对其进行抗高温氧化性能测试，对高温氧化前后的涂层进行电子探针分析。结果表明：低功率快扫描速度下的激光控制反应合成涂层成型质量良好，与基体形成冶金结合，并且连续致密无裂纹，对基体影响小。从基体到涂层表层垂直方向分别为沿基体生长的平面晶区、柱状晶区和表层等轴晶区，涂层主要由Ni／Al金属间化合物组成。高温氧化前后涂层各元素的组成几乎无变化，涂层抗高温氧化性能优良。

Laser Controlled Reactive Synthesized Ni/Al Intermetallics Coating

Laser synthesized Ni/Al intermetallics coating was prepared on a cast steel by CO2 laser. The microstructure and phases synthesized materials were analyzed by SEM and XRD. Resistance to high temperature oxidation was tested as well. The composition of the coating before and after high temperature oxidation were analyzed by EPMA. The results indicated that laser controlled reactive synthesized coating under low power and fast velocity conditions can be melted well, and a metallurgical bond with substrate can be obtained. The coating was continuous, compact, and flawless, and it mostly was made up of flat crystal, columnar crystal and equiaxial grain zones from base metal to the coating surface. The coating was mainly composed of Ni/Al intermetallics. Every element of the coating composition was almost unchanged after high temperature oxidation. The oxidation resistance of laser synthesized coating of Ni/Al intermetallics is excellent.