The transformation of an Al-based crystalline electrode material to an amorphous deposit via the electrospark welding process

The electrospark welding process (ESW) has successfully been used to weld an aluminum-based crystalline alloy (Al71.2Co12.2Ce16.6) to a zirconium-based amorphous substrate. Due to the high cooling rates involved in the ESW process, the Al71.2Co12.2Ce16.6 alloy transformed into an amorphous deposit without crystallizing the substrate. This result was confirmed by X-ray diffraction. An average deposit thickness of 40 +/- 10 mu m has been obtained after 10 passes. A second series of experiments have been performed using the Al71.2Co12.2Ce16.6 alloy as both the electrode and substrate material. These tests were performed to eliminate any dilution between substrate and weld deposit. Electron backscatter diffraction (EBSD) was used to verify the amorphicity of the deposit. The average weld thickness is 12 +/- 8 mu m obtained after 10 passes. It is envisioned that the process can be used for the weld repair of worn amorphous or other heat sensitive advanced materials. (C) 2008 Elsevier B.V. All rights reserved.