EFFECT OF POST PRODUCTION HEAT TREATMENT ON γ-TiAl ALLOYS PRODUCED BY GTAW- BASED ADDITIVE MANUFACTURING PROCESS

摘要

In this work, an additive layer manufacturing (ALM) process based on gas tungsten arc welding (GTAW) was used to produce simple 3-dimensional titanium aluminide components, which were successfully in-situ alloyed by separately delivering elemental Al and Ti wires to the weld pool. Investigations were conducted on the additively manufactured γ-TiAl based alloy to assess the influence of heat treatment on the microstructure evolution, phase transformations and some other basic properties. The results indicated that heat treatment promotes the formation of the γ phase. This microstructural change resulted in the reduction of the microhardness mainly due to the reduction of the hard, brittle α2 phase.