A novel crack-free and refined 2195-Ti/CeB6 composites prepared by laser powder bed fusion

Laser powder bed fusion (LPBF) of Al-Li alloys has high susceptibility to cracking due to wide solidification temperatures and formation of low-temperature eutectics. In this work, 2195 Al-Li alloys and 2195-Ti/CeB6 composites were manufactured at relatively high scan speeds and compared to reveal the effect of Ti/CeB6 on the crack inhibition and mechanical properties of 2195 alloys. The Ti/CeB6 addition showed a significant effect on grain refinement of 2195 alloys, where the grains changed from coarse columnar (-36.3 mu m) to fine equiaxed grains (-2.8 mu m) and their size was reduced by one order of magnitude. The 2195-Ti/CeB6 composites exhibited good laser processability without cracks at relatively high scan speeds. High tensile strength of-300 MPa and elongation of-5.5 % for the composites at a high scan speed are obtained, respectively increasing by 33 % and 35 % relative to crack-free alloys at low scan speeds. This study provides references to crack suppression for laser additive manufacturing of high-crack-susceptibility metallic alloys.