旧版下载已关闭,请移步到新版下载(点击打开新版

Selective laser melting 3D printing of Ni-based superalloy:understanding thermodynamic mechanisms

资料来自用户(Jack)上传,若本站收录的文献无意侵犯了您的著作版权,请点击版权申明
文献出处
Science Bulletin  2016年13期
机 构
College,of,Materials,Science,and,Technology,Nanjing,University,of,Aeronautics,and,Astronautics,Institute,of,Additive,Manufacturing,(3D,Printing),Nanjing,University,of,Aeronautics,and,Astronautics
基 金
supported,by,the,National,Natural,Science,Foundation,of,China,(51575267,51322509),the,Top-Notch,Young,Talents,Program,of,China,the,Outstanding,Youth,Foundation,of,Jiangsu,Province,of,China,(BK20130035),the,Program,for,New,Century,Excellent,Talents,in,University,(NCET-13-0854),the,Science,and,Technology,Support,Program,(the,Industrial,Part),Jiangsu,Provincial,Department,of,Science,and,Technology,of,China,(BE2014009-2),the,333,high-level,talents,training,project,(BRA2015368),the,Science,and,Technology,Foundation,for,Selected,Overseas,Chinese,Scholar,Ministry,of,Human,Resources,and,Social,Security,of,China,the,Aeronautical,Science,Foundation,of,China,(2015ZE52051),the,Shanghai,Aerospace,Science,and,Technology,Innovation,Fund,(SAST2015053),the,Fundamental,Research,Funds,for,the,Central,Universities,(NE2013103,NP2015206,and,NZ2016108),the,Priority,Academic,Program,Development,of,Jiangsu,Higher,Education,Institutions
论文摘要

A mesoscopic model has been established to investigate the thermodynamic mechanisms and densification behavior of nickel-based superalloy during additive manufacturing/three-dimensional(3D) printing(AM/3DP)by numerical simulation, using a finite volume method(FVM). The influence of the applied linear energy density(LED) on dimensions of the molten pool, thermodynamic mechanisms within the pool, bubbles migration and resultant densification behavior of AM/3DP-processed superalloy has been discussed. It reveals that the center of the molten pool slightly shifts with a lagging of 4 lm towards the center of the moving laser beam. The Marangoni convection, which has various flow patterns, plays a crucial role in intensifying the convective heat and mass transfer, which is responsible for the bubbles migration and densification behavior of AM/3DP-processed parts. At an optimized LED of 221.5 J/m, the outward convection favors the numerous bubbles to escape from the molten pool easily and the resultant considerably high relative density of 98.9 % is achieved. However, as the applied LED further increases over 249.5 J/m, the convection pattern is apparently intensified with the formation of vortexes and the bubbles tend to be entrapped by the rotating flow within the molten pool, resulting in a large amount of residual porosity and a sharp reduction in densification of the superalloy. The change rules of the relative density and the corresponding distribution of porosity obtained by experiments are in accordance with the simulation results.

全文下载
全文下载