Structure, properties and fracture of electron beam welds in RS-PM Al8FeMo

• Published in: Materials science and engineering 1988-02, Vol.98, p.137-141
• Main Authors: Krishnaswamy, S., Baeslack, W.A.
• Format: Article
• Language: English
• ISSN: 0025-5416
• DOI: 10.1016/0025-5416(88)90142-5

Electron beam welds were produced in rapidly-solidified, powder metallurgy (RS-PM) Al-8wt.%Fe-2wt.%Mo sheet using a range of energy inputs and metallurgically characterized with respect to microstructure, mechanical properties and fracture behavior. A reduction in the electron beam energy input required to produce autogenous, full-penetration welds and the associated increase in weld solidification and cooling rates were found to promote increasingly finer fusion zone microstructures comprising primary intermetallics and dendritic alpha aluminum (zone B type). Welds produced at the lowest energy inputs exhibited fusion zone hardnesses superior to that of the base metal, joint efficiencies exceeding 85% and acceptable ductilities. The use of a minimal energy input also prevented the formation of a structurally-coarsened region near the fusion boundary which served as the weak link in higher energy input weldments. Weld failure in this coarsened region was associated with delamination of the coarse intermetallic-alpha aluminum interfaces.