Correlative spatter and vapour depression dynamics during laser powder bed fusion of an Al-Fe-Zr alloy  

作　　者：Da Guo Rubén Lambert-Garcia Samy Hocine Xianqiang Fan Henry Greenhalgh Ravi Shahani Marta Majkut Alexander Rack Peter D Lee Chu Lun Alex Leung 

机构地区：[1]UCL Mechanical Engineering,University College London,London WC1E 7JE,United Kingdom [2]Research Complex at Harwell,Harwell Campus,Didcot OX110FA,United Kingdom [3]HiETA Technologies,Bristol BS167FR,United Kingdom [4]Constellium Technology Centre,38341 Voreppe,France [5]ESRF—The European Synchrotron,38000 Grenoble,France

出　　处：《International Journal of Extreme Manufacturing》2024年第5期298-310,共13页极端制造（英文）

基　　金：support from the UKRI-EPSRC,Grants Numbered EP/W006774/1,EP/P006566/1,EP/W003333/1,and EP/V061798/1;funded by the support from a Royal Academy of Engineering Chair in Emerging Technologies(CiET1819/10);CLAL is funded in part by EP/W037483/1 and IPG Photonics/Royal Academy of Engineering Senior Research Fellowship in SEARCH(ref:RCSRF2324-18-71);This research used resources of the European Synchrotron Radiation Facility(ESRF)in Beamline ID19(ME-1573).

摘　　要：Spatter during laser powder bed fusion(LPBF)can induce surface defects,impacting the fatigue performance of the fabricated components.Here,we reveal and explain the links between vapour depression shape and spatter dynamics during LPBF of an Al-Fe-Zr aluminium alloy using high-speed synchrotron x-ray imaging.We quantify the number,trajectory angle,velocity,and kinetic energy of the spatter as a function of vapour depression zone/keyhole morphology under industry-relevant processing conditions.The depression zone/keyhole morphology was found to influence the spatter ejection angle in keyhole versus conduction melting modes:(i)the vapour-pressure driven plume in conduction mode with a quasi-semi-circular depression zone leads to backward spatter whereas;and(ii)the keyhole rear wall redirects the gas/vapour flow to cause vertical spatter ejection and rear rim droplet spatter.Increasing the opening of the keyhole or vapour depression zone can reduce entrainment of solid spatter.We discover a spatter-induced cavity mechanism in which small spatter particles are accelerated towards the powder bed after laser-spatter interaction,inducing powder denudation and cavities on the printed surface.By quantifying these laser-spatter interactions,we suggest a printing strategy for minimising defects and improving the surface quality of LPBF parts.

关 键 词：SPATTER vapour depression x-ray imaging DEFECTS surface quality 

分 类 号：TG665[金属学及工艺—金属切削加工及机床] TG146.21[一般工业技术—材料科学与工程]