Manufacturing of Porous Ni-Al Intermetallics by Direct Laser Reaction Sintering

Porous Intermetallic Ni-Al alloys were fabricated by laser reactive sintering technique (laser-induced self-propagation sintering). The heat of formation of the intermetallics was sufficient to obtain bulk products whereas pores were formed during the reaction. The aluminum-to-nickel ratio was an important factor controlling the porosity of the synthesized nickel aluminide alloy. The recorded relative density of the green compact was more than 73% for effective foam formation. The exothermic behavior of the alloys was characterized by the relation between the starting reaction time and the Al content. The different phases of the sintered alloys formed during the sintering process were identified by X-ray diffraction, and the microstructure was studied.