Analysis on embrittlement phenomenon of flux cored Zn–Al wire

Abstract

The microstructures and properties of fresh, artificial aged and natural aged flux cored ZnAl15 wires were investigated by scanning electron microscope (SEM) and energy dispersive X-ray (EDX) spectrometer techniques. The results of SEM showed that continuous precipitation of η_s phase occurred and the dissolved contents of both α_s phase and η_s phase reduced during the aging process of ZnAl15 wire, which led to the increase in Vickers microhardness. The results of the EDX presented that the oxygen absorption corrosion led to the embrittlement of ZnAl15 wire, which decreased the number of reverse bends. In addition, the phase transformation stress accelerated the corrosion, and finally, the natural aged ZnAl15 wire resulted in stress corrosion crack under the comprehensive effects of corrosion and phase transformation stress.