EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

The objective of the present study is to observe the microstructural modifications from equiatomic simple mixture with finer Ni (oxyreduction) and coarse Ti HDH (hydration-dehydration) elemental powders as green bodies pressed when reactive sintering occurs using a Yb:fiber laser source. Processing was done using a Yb:fiber laser with 2 mm diameter, in order to evaluate the reaction exothermicity associated to laser-powders interaction. The parameters change effects such as power (40 to 200 W) and scanning speed (4 to 6 mm/s) of the laser source on the irradiated samples were observed, investigating the ignition occurrence for reactive sintering between Ni and Ti particles and the microstructural change level in which it occurred along the green body pressed sample thickness. When sintered bodies was observed in region that comprises the laser can beginning and the end by optical and scanning electron microscopy techniques, the presence of three distinct zones was found: the scan start, where there is only the punctual laser action on the incident face; an intermediate transition portion along the thickness, which marks the reactive sintering ignition; and the end characterized by the energy propagation effect taking entire thickness between the incident face to opposite face laser action.