Real-time porosity reduction during metal directed energy deposition using a pulse laser

作     者：Hoon Sohn Peipei Liu Hansol Yoon Kiyoon Yi Liu Yang Sangjun Kim Hoon Sohn;Peipei Liu;Hansol Yoon;Kiyoon Yi;Liu Yang;Sangjun Kim

作者机构：Department of Civil and Environmental EngineeringKorea Advanced Institute of Science and Technology(KAIST)Daejeon 34141Republic of Korea Center for 3D Printing Nondestructive TestingKorea Advanced Institute of Science and Technology(KAIST)Daejeon 34141Republic of Korea Global R&D CenterSQ EngineeringSeoul 05818Republic of Korea Department of Civil and Environmental EngineeringThe Hong Kong University of Science and TechnologyClear Water BayKowloonHong KongChina 

出 版 物：《Journal of Materials Science & Technology》 (材料科学技术（英文版）)

年 卷 期：2022年第116卷第21期

页      面：214-223页

核心收录：

学科分类：08[工学] 0802[工学-机械工程] 080201[工学-机械制造及其自动化] 

基　　金：supported by a National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)[Grant No.2019R1A3B3067987] supported by SQ Engineering during his stay at KAIST 

主　　题：Real-time porosity reduction Pulse laser Melt pool Directed energy deposition Ti-6Al-4V 

摘      要：Porosity is a challenging issue in additive manufacturing and is detrimental to the quality of the additively manufactured *** this study,a real-time porosity reduction technique was developed by incorporating a pulse laser into a laser metal powder directed energy deposition(DED)*** incorporated pulse laser can accelerate fluid flow within the melt pool and facilitate the escape of pores before complete *** achieves this real-time porosity reduction by inducing accelerated and turbulent Marangoni flow,ultrasonic waves,and shock waves into the melt *** uniqueness and advantages of the proposed technique include the following:(1)For a laser metal powder DED process,this study proposed a noncontact,nondestructive,and real-time porosity reduction technique at the melt pool level.(2)It was experimentally and numerically validated that the developed technique did not alter the geometry and the grain structure of the manufactured Ti-6Al-4V samples.(3)Because the porosity reduction is accomplished at the melt pool level,its application is not limited by the size,shape,or complexity of the printing target.(4)The developed technique can be readily incorporated into the existing DED systems without any modification of the original tool-path *** experimental results showed that the pore volume fraction decreased from 0.132%to 0.005%,no pores larger than 6×10^(4)μm^(3) were observed,and a 91%reduction in the total pore number was achieved when the pulse laser energy reached 11.5 mJ.