一种爆炸喷涂NiCrAl尺寸修复涂层的工艺研制

Process Development of D-Gun Sprayed NiCrAl Coating forDimensional Build-Up

采用正交试验设计方法,研究了粉末粒度、氧燃比、送粉氮气流量和喷涂距离4因素对爆炸喷涂NiCrAl涂层组织和性能的影响,并利用扫描电镜对涂层微观组织进行了研究,通过对涂层孔隙率、显微硬度和拉伸结合强度的检测,研究了4因素对涂层性能影响的规律。根据正交试验结果,确定优化后的工艺参数为粉末粒度13~45μm,氧燃比为1.25,送粉氮气流量20 L/min,喷涂距离170 mm。优化工艺后喷涂的NiCrAl涂层组织均匀致密、硬度高、拉伸结合强度好。

Based on the orthogonal experiment,effects of power particle size,oxygen-fuel ratio,flow rate of carrier N2 and spray distance on microscopic structure and mechanical properties of D-gun sprayed NiCrAl coatings were investigated.The characterizations of microstructure of as-sprayed coatings were analyzed by SEM.The influence of four factors on the coating properties was studied by testing the porosity,microhardness and tensile bonding strength of the coating.The optimized process parameters of the D-gun sprayed NiCrAl coatings were particle size 13-45μm,oxygenfuel ratio 1.25,flow rate of carrier N220 L/min and spray distance 170 mm.An NiCrAl coating for dimensional build-up application with uniform,dense microstructure,high hardness and adhesive strength was achieved through the D-gun spray process optimization.