粉末利用次数对发动机用Inconel718合金激光熔覆修复性能的影响

对激光熔覆Inconel718合金进行粉末进行回收利用,并以该粉末作为熔融修复原料制备激光熔覆涂层,测试试样组织各项力学特性参数。研究结果表明:经过回收利用处理后,各粉末颗粒尺寸差异较大,形成了许多细小的颗粒并且外形也不太规则。提高利用次数后,获得了粒径更大的粉末颗粒,由56提高至79μm。经过筛分处理获得的杂质粉末颗粒微观组织基本都属于球形结构,其表面也较粗糙。随着粉末利用次数的增加,损失率表现出单调减小变化。在熔覆层中形成了由枝晶与等轴晶共同构成的组织相,枝晶发生了外延生长。经过更多次利用处理后,熔覆试样组织内形成了更粗大的晶粒,降低了组织分布均匀性和弯曲强度。

Recycle and Reuse of Inconel718 Alloy Powder as Laser Cladded Coating Material

The wasted Inconel-718 alloy powder,an advanced aircraft engine material,was recycled and reused as a homogeneous coating material in repairing surface damage of components by laser cladding.The influence of the recycling times on the powder microstructure and tribological behavior of the laser cladded coatings was investigated with X-ray diffraction,energy dispersive spectroscopy,scanning electron microscopy and mechanical probes.The preliminary results show that the recycling time matters.For example,as the recycling time increased,the average-size,irregularity and surface roughness of the spherical grain increased from 56 to 79 μm,owing to the grain growth in laser melting,and the loss-rate monotonically decreased.The bending strength of the laser cladded coating,synthesized with the powders recycled for three times and comprising equiaxed grains and epitaxial dendric textures,considerably decreased,possibly because of larger grain-size and greater non-uniformity of microstructures.