Effect of Thermal Cycling on Grain Evolution and Micro-Segregation in Selective Laser Melting of FGH96 Superalloy

Extremely rapid heating and cooling rates during the additive manufacturing (AM) process generate complicated thermal cycles, which affect microstructure evolution ultimate mechanical properties of alloy. In this paper, FGH96 blocks with a height 6 mm were prepared by selective laser melting (SLM) was characterized scanning electron microscopy (SEM) transmission (TEM). Comparing specimens varying heights, it found that subsequent cycles (STC) coarsened some solidified grains accelerated grain growth along build direction, together an increase in texture intensity high-angle boundaries (HAGBs). After coarsening middle portion built block, finer observed near top area due to faster rate. There numerous dislocations because occurrence unequal internal tension. sample stable both perpendicular direction 45° off it. spite characteristics, segregation elements also be influenced cycling. Inherent reheating leads Laves phase decrease ?’ as deposition. This one reasons why microhardness decreased building other reason being solution treatment later sediments.