Mitigating hot-cracking of laser melted CoCrFeNiMnTix high-entropy alloys

Additive manufacturing is a promising technique for fabricating high-alloyed metallic components such as CoCrFeMnNi high-entropy alloy with very fine microstructure and reduced macro-segregation. However, hot cracking nucleation at the interdendritic regions always occurs during preparation, which can hardly be controlled. In this study, the hot cracking possibility could be reduced by introducing element Ti into CoCr-FeMnNi high-entropy alloy with the improved alloy microhardness (182 +/- 8.7 HV to 973 +/- 43.2 HV). At the final solidification stage, eutectic interaction takes place in the interdendritic regions. Body-centered-cubic (BCC) and a few a phases form, dividing the liquid film and releasing the local stress concentration. CoCrFeNiMnTi0.6 sample without cracks is observed.

Automated summary

In this study, the possibility of hot cracking in CoCrFeMnNi high-entropy alloy was successfully reduced by introducing Ti element, resulting in improved alloy microhardness, and crack-free CoCrFeNiMnTi0.6 sample was observed.