Time-dependent deformation behaviour of lead-based bearing alloys during transformation

This paper presents the result of a study of the transient creep behaviour of Pb–10 wt.%Sn and Pb–10 wt.%Sn–1.5 wt.%Zn bearing alloys. The isothermal creep curves for the two alloys were obtained under different constant applied stresses at different working temperatures ranging from 373 to 443 K. The creep data were fitted by the power law equation; εtr=βtn, where β is the creep coefficient and n the creep exponent. The transient creep parameters β and n as a function of the working temperature were calculated. Differential thermal analysis (DTA) and X-ray of the alloy samples were studied to evaluate the structural changes during transformations. The effect of Zn-content on the creep behaviour and the transition temperature as well as the melting temperature were discussed. Microstructural examinations of the deformed samples below and above the transition temperatures were investigated.