首页 | 本学科首页   官方微博 | 高级检索  
     


The Influence of Laser Defocusing in Selective Laser Melted IN 625
Authors:Alexandru Paraschiv,Gheorghe Matache,Mihaela Raluca Condruz,Tiberius Florian Frigioescu,Ion Ionică  
Affiliation:1.Special Components for Gas Turbines Department, Romanian Research and Development Institute for Gas Turbines COMOTI, 220D Iuliu Maniu, 061126 Bucharest, Romania; (G.M.); (M.R.C.); (T.F.F.);2.SC Plasma Jet SRL, 401E Atomiștilor, 077125 Magurele, Romania;
Abstract:Laser defocusing was investigated to assess the influence on the surface quality, melt pool shape, tensile properties, and densification of selective laser melted (SLMed) IN 625. Negative (−0.5 mm, −0.3 mm), positive (+0.3 mm, +0.5 mm), and 0 mm defocusing distances were used to produce specimens, while the other process parameters remained unchanged. The scanning electron microscopy (SEM) images of the melt pools generated by different defocusing amounts were used to assess the influence on the morphology and melt pool size. The mechanical properties were evaluated by tensile testing, and the bulk density of the parts was measured by Archimedes’ method. It was observed that the melt pool morphology and melting mode are directly related to the defocusing distances. The melting height increases while the melting depth decreases from positive to negative defocusing. The use of negative defocusing distances generates the conduction melting mode of the SLMed IN 625, and the alloy (as-built) has the maximum density and ultimate tensile strength. Conversely, the use of positive distances generates keyhole mode melting accompanied by a decrease of density and mechanical strength due to the increase in porosity and is therefore not suitable for the SLM process.
Keywords:SLM   defocusing   IN 625   melt pool   tensile testing   density
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号