Impact of temperature on the mechanical properties of Al-4.3Cu-Pb bearing alloys

Abstract

Leaded aluminium copper plain bearing alloys, were prepared by impeller mixing of charge at 973K followed by chill casting in a grey cast iron split type mould. Mechanical properties of as cast alloys measured at ambient, 323, 373, 423 and 473 K indicated a decline in properties with rise in test temperature and lead content, whereas percentage elongation showed a rising trend. Ultimate tensile strength of Al-4.3Cu-(O-40)Pb alloys decreased from 196.2 MPa to 54.3 MPa and % elongation increased from 10.1 to 19.2 when the test temperature was raised from ambient to 473 K and the lead content from 0 to 40 wt.%. Microstructure of as cast alloys exhibited uniform dispersion of lead (30 wt.% Pb) in aluminium copper alloy. Thickness of lead pockets increased with lead content of alloy. SEM of fractured surface exhibited a ductile mode of fracture at elevated temperature. © Meshap Science Publishers.