Microjoining of Ni 3 Al based intermetallic thin foils

Abstract

A preliminary analysis of the joining ability of thin Ni₃Al (Zr, B) based foils (below 150 μm thickness) into ‘honeycomb’ structures by various techniques is described in this work. Resistance welding, CO₂ laser welding and microplasma arc welding, as well as explosive welding, were used in the investigations. The examinations conducted in this study of the joint microstructures obtained by each technique do not reveal the existence of a heat affected zone. Columnar grains with a longer axis, as determined by the direction of heat flow, were observed along the fusion lines. Changes in microhardness were also examined along with a microanalysis of the chemical composition of the joint cross-section. Preliminary tests of the joining of thin Ni₃Al foil into ‘honeycomb’ experimental structures were carried out.