Friction and wear properties of steel backed Al–10Sn–4Si–1Cu metallic strips prepared via spray atomization–deposition-rolling route

Abstract

In various load bearing structural applications related to automotive industries, steel backed aluminum alloy strips are considered. For such applications, it is desired to design appropriate alloy composition for metallic strip so that good tribological properties can be achieved. In our ongoing efforts to accomplish this aim,we have recently fabricated a steel backed Al–10Sn–4Si–1Cu bearing strip, which is prepared by spray depositing the molten bearing alloy on a steel substrate, followed bywarm rolling of the resulting laminated strip to different thickness reductions up to 80%. The tribological performance of the steel backed Al–10Sn–4Si–1Cu strips is evaluated against the bearing steel. While the recorded steady state coefficient of friction (COF) does not show any noticeable difference (varying in the range of 0.6–0.7) with respect to difference in warm rolling conditions, the fretting wear rate (10–26×10−5 mm3 N−1m−1) of the steel backed and warm rolled strips exhibits a systematic decrease in wear rate with increase in amount of warm rolling. SEM-EDS analyses reveal the oxidative wear and the extensive cracking of alumina rich tribolayer as the dominant material removal mechanisms. The tribological properties of the spray deposited and 80% rolled steel backed Al–10Sn–4Si–1Cu bearing strip is compared with those of a commercially available Al–Sn based sleeve bearing under identical fretting conditions.