(S156)Fabrication of heat-resistant Mo-Ti-Al alloys by powder bed fusion process using fiber laser

摘要

Heat-resistant alloys are generally used in aircraft engines, such as turbine blades, vanes, and so on. In order toincrease the thermal efficiency of turbine engines, higher operating temperatures is required which cannot be realizedwith Ni-base superalloys. Therefore, it is required to develop novel heat-resistant alloy having superior heat-resistantproperties to conventional alloys. We focused Molybdenum (Mo) showing high melting point and low thermalexpansion coefficient. However, the use of Mo is limited owing to the severe oxidation above about 650℃. Al and Tiare promising alloying elements to improve the oxidation resistance due to the formation of protective Al2O3/TiO2oxides layer. On the other hand, powder bed fusion process using a laser (PBFL) process has attracted increasingattention in biomedical and aerospace industries, because PBFL has the ability in fabricating complex structurecompared to conventional manufacturing routes. In this study, we tried to fabricate in-situ Mo-Ti-Al alloys using PBFLwith Mo and TiAl powder, which is one of the effective way to avoid the preparation of Mo-Ti-Al alloy powders.Microstructure and mechanical properties of PBFLed in-situ Mo-Ti-Al alloys were also investigated.