工艺参数对电弧喷涂NiAl涂层结合强度的影响

以涂层结合强度为判据,采用Ni-Al丝材和PARXAIR-9935电弧喷涂系统制备镍基涂层,通过正交试验对电弧喷涂NiAl合金工艺进行了优化。利用在线检测系统对焰流的强度、粒子的速度和温度进行检测,通过金相显微镜、扫描电镜、能谱仪等手段对涂层和断口形貌进行分析。结果表明,喷涂电流、喷涂电压、雾化空气压力、喷涂距离对NiAl合金涂层结合强度具有不同程度的影响,确定优化后的工艺参数为喷涂电流150A,喷涂电压27V,雾化空气压力0.6MPa,喷涂距离150mm。在优化工艺参数条件下,电弧喷涂NiAl合金涂层组织呈现出典型的层状结构;并且随着涂层厚度的增加,结合强度呈线性下降,其最大结合强度可达39.8MPa。

Effect of Processing Parameters on Adhesion Strength of Arc Sprayed NiAl Coating

Ni-based coating were prepared by Ni-Al wire and arc spraying system（Model PARXAIR-9935）. The arc spraying process was optimized by orthogonal experiment design with using adhesive strength level as the criterion.Online testing equipment was used to detect the flame flow strength,Particle velocity and temperature. Morphology of the sprayed layer and the fracture of the coating were investigated by means of metallographic microscope, scanning electron microscopy（ SEM ） and energy dispersive spectrometry（EDS） .The results show that the spraying distance, atomizing air pressure, arc current, arc voltage have different effect on the adhesive strength of NiAl coating.The optimized process parameters of the arc spraying NiAI coating were spray current 150A, spray voltage 27V, atomizing air pressure 0.6MPa and spray distance 150mm.The coating displays the typical layer structure characteristic with good compactness using the optimized parameters.With the increase in the thickness of the coating,the bonding strength decreases linearly. The highest adhesive strength of theNiAl coating with 39.SMPa can be obtained using the optimized parameters.