Solid-State Additive Manufacturing of Titanium Alloys using MELD Process

Industrial interest to utilize additive manufacturing (AM) processes for fabrication of large scale and near-net shape parts has largely increased in past few decades. This is due to the potentials for significant savings in raw material, lead time, and finish machining, as well as the ability to produce complex geometries that are not feasible with traditional manufacturing methods. Most melt-based AM processes require use of powders in vacuum chambers, as well as the post processing is an additional step for most melt-based AM such as HIP or sintering due to presence of some defects created during rapid solidification process. MELD is a fully solid-state AM process that can use off-shelf materials to print a near net shape large components which are fully dense with less distortion and residual stress compared to most other AM technologies. This presentation will overview the development of the MELD process for titanium alloys, including Ti-6-4 and Ti-10-2-3.

It has been demonstrated that the key processing factor in AFSD for a good performing material is temperature control deposition. This work will discuss the characteristics of as-printed materials fabricated using MELD process. This would include microstructure, chemical and density analysis, mechanical properties such as tensile and high cycle fatigue performance. The effect of heat treatment on tensile properties will also be discussed. The results suggests that MELD Ti-6-4 and Ti-10-2-3 exceeds the minimum requirements for die-forging.