Microstructure and hydrogen storage properties of a TiZrNbMoV high entropy alloy synthesized using Laser Engineered Net Shaping (LENS)

Laser Engineered Net Shaping (LENS) with laser powers of 300 W and 1 kW was used to synthesize the TiZrNbMoV high entropy alloys (HEA) from a blend of elemental powders. The morphology of the elemental powders was investigated using a scanning electron microscope (SEM) and an infrared particle size analyzer. The chemical composition and microstructure of the synthesized TiZrNbMoV alloys were investigated using an X-ray diffractometer (XRD) and SEM coupled with an energy-dispersive X-ray spectrometer (EDS). The hydrogen absorption and desorption properties of the synthesized TiZrNbMoV alloys were investigated using a Sieverts-type apparatus. After synthesis using a low laser power, the TiZrNbMoV alloy exhibited a two-phase dendritic matrix with some unmelted Mo particles and dendrites of a bcc solid solution surrounded by an orthorhombic NbTi4-type phase. The alloy that was deposited using a laser power of 1 kW and remelted three times possessed a multi-phase microstructure with a Mo-rich matrix containing Zr-rich precipitates and no dendritic segregation. The influence of the technological parameters employed during laser deposition on the microstructure and hydrogen storage properties of the synthesized TiZrNbMoV alloys will be presented and discussed. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.