Structural and thermal characteristics of Ti6Al4V (Ti64) metal powders for direct energy deposition

Abstract

Ti6Al4V metal powder has been widely utilized in direct energy deposition (DED) of additive manufacturing (AM) technology, especially in aerospace applications. However, to secure excellent weldability between metal powder and substrate requires a proper understanding of heat-dissipation energy/created, especially when involving two components/materials with different thermal coefficients or properties. Therefore, an attempt is made in this work to investigate the structural and thermal characteristics of powder metals, including precursor powders such as Ti, Al, V, Al-V, and commercial established powder of Ti6Al4V (Ti64), respectively. Qualitative and quantitative analyses were employed accordingly to determine phase composition via X-ray diffraction (XRD) analyses. While phase stability, such as the thermal reaction and transition (ΔH) of these powders, was evaluated using differential scanning calorimetry (DSC). These findings are essential, especially in determining the reaction mechanism involved in various applications such as deposition process, mechanical alloying, and reaction sintering under a controlled environment. These fundamental characteristics are essential in producing high purity Ti64 metal powders and improve the weldability of the metal joining.