Formation of NiAl Intermetallic Compound from Powder Mixture of Nickel and Aluminum by Laser Irradiation

Abstract

NiAl intermetallic compound was formed by laser irradiation on powder mixture of nickel and aluminum. In laser irradiation with an average energy density of 150 J/mm² using a continuous wave 50 W Nd:YAG laser, Ni–49 at% Al powder mixture was immediately heated up to a temperature above 1680 K by reaction heat on the interface between nickel and aluminum powders. As the result, the powder mixture was ignited with maximum bulk volume of approximately 1.0 × 10⁴ mm³, and the powder mixture was partly melted. After solidification of the melted part by natural cooling, the formation of NiAl intermetallic compound was confirmed from the results of microscopic observations, hardness measurement, EDX and XRD analyses.