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本文研究了激光直接制造镍基高温合金FHG95的工艺。通过不同的参数搭配共进行 314个试样的实验 ,按照一定标准 (宽度波动小于 5 %,单层熔覆厚度大于 0 .2mm ,表面没有粉末黏着 )选取成形效果较好的试样 ,分析总结了选择优化工艺参数的规律。分析了功率密度、送粉速度、扫描速度单独作用的机理和相互配比的方式 ,提出了送粉量承载率的概念 ,同时给出如何针对不同的熔覆层宽度、厚度选取工艺参数的方法。按照该工艺方法激光直接成形的镍基高温合金零件晶粒细小、组织致密 ,而且各元素含量与粉末相同 ,没有偏析。当熔覆基体尺寸为 2 0 0× 15 0× 2 5mm的低碳钢板时 ,激光功率密度应该在15 0 - 2 0 0W /mm2 ,扫描速度在 0 .2 - 0 .3m/min ,每瓦激光所能承担熔覆的合金粉末为 0 .0 2 g/min。当加工薄壁零件时 ,熔覆速度应大于 0 .5m/min ,单层熔覆厚度约为 0 .1mm。
This paper studies the laser direct manufacturing of nickel-based superalloy FHG95 process. A total of 314 samples were tested with different parameters. According to a certain standard (width less than 5%, single-layer cladding thickness greater than 0.2 mm, no powder adhesion on the surface), samples with better forming effect were selected and analyzed. The choice of the rules of optimization of process parameters. The mechanism of power density, feeding speed and scanning speed alone are analyzed. The concept of feeding rate of feeding capacity is put forward. At the same time, how to select process parameters according to different width and thickness of coating is given . In accordance with the process of direct laser forming nickel-based superalloy parts fine grain, dense tissue, and the same content of the elements and powder, no segregation. When cladding a mild steel plate with a size of 200 × 150 × 250 mm, the laser power density should be between 150 and 200 W / mm2 and the scanning speed between 0.2 and 0.3 m / min per watt The alloy powder that the laser can bear the cladding is 0. 02 g / min. When processing thin-walled parts, the cladding speed should be greater than 0 .5m / min, single-layer cladding thickness of about 0.1mm.