Research On Process Experiment Of Selective Laser Melting With GH4169Nickel-based Alloy Powder

Selective Laser Melting is a new3D Printing technology, which can directly produceterminal or near-terminal metal products. The technology of Selective Laser Melting withGH4169Nickel-based alloy powder is still immature in foreign countries and the research onSLM is rare in china. Based on these, the experiments which chose GH4169Nickel-basedalloy powder as the test material are carried out with LWY400P laser equipment. It can lay thefoundation for future studies of Nickel-based alloy powder with SLM.This paper explores the laser electric current, the laser light frequency, the laser pulsewidth, the scan speed, the push powder thickness and the scan interval which have influenceon the formability, the density the micro hardness of GH4169Nickel-based alloy with thescanning way on Single-layer single-channel scanning, single-layer multi-channel scanningand multi-level multi-channel scanning. The forming mechanism of defects, such asspheroidizing, pore, crack, warp and splash are explored and the ways of reducing defects aresuggested. The process parameters are optimized and block specimen was formed with theoptimal process parameters. The formability of GH4169powder with Re element wasexplored preliminarily.It was found that the width and the height of the scanning line increased as the laserelectric current, the laser pulse width, the laser light frequency added and the scan speedreduced. The push powder thickness has a little influence on the width of the scanning line,but it presented a positive correlation with the height of the scanning line. If the processparameters are too large or too small, the density and micro-hardness of the forming parts isnot perfect. The optimal process parameters were the laser electric current of140A, theScanning speed of150mm/min, the scan interval of0.35mm, the laser pulse width of5.5ms, the laser light frequency of12Hz, the push powder thickness of0.15mm. The surface of theforming parts with SLM is flat on the whole. The density of the block specimen with theoptimal process parameters is98.45%and the micro-hardness of the block specimen with theoptimal process parameters is427HV.