Abstract:
Objective Relationship between the process parameters and the density of the GH4099 alloy sample manufactured by selective laser melting was systematically studied to improve the density of the samples.
Methods The process parameters of pluse current crack arrest of GH4099 additive specimen were investigated, and the changes in the microstructure and densification when of the samples before and after pulse current treatment were analyzed.
Results The results show that the density of sample is the highest, while the scanning speed is 960 mm/s, laser power is 290 W, scanning distance is 0.11 mm, the highest density of the sample is 8.485 2 g/cm
3, but cracks still exist in the sample. While DC pulse current is applied, the crack spacing at the larger crack area is reduced by 58%, which shows the healing trend. And the crack area at the smaller crack area is healed. The average density of the sample is increased by 0.061 6 g/cm
3.
Conclusion It verifies the feasibility of selective laser melting of GH4099 alloy crack by pulsed current crack arrest.