SiC particle reinforced Al matrix composites brazed on aluminum body for lightweight wear resistant brakes

Abstract

Aluminum alloys are well known light-weight alloys and very interesting materials to optimize the strength/weight ratio in order to reduce automotive vehicle weight, fuel consumption and CO2 emissions; unfortunately, they are also relatively soft and therefore cannot be used for high wear applications.The aim of this work was to develop an aluminum alloy brake disc with wear-resistant SiC particle reinforced aluminum matrix composites (SiC/Al) joined on to its surface.Different approaches based on brazing or shrink fitting joining technologies were used to join SiC/Al to the aluminum alloy surface.A functional graded structure was built by brazing thin layers of aluminum matrix composites reinforced with progressively higher amount of SiC particles by using a Zn–Al based alloy as joining material. Several samples were prepared by shrink fitting and brazing: 40 mm x 40 mm x 10 mm samples and a 100 mm diameter brake disc with 68% SiC particle reinforced Al matrix surface and aluminum alloy A365 body. Tribological tests demonstrated that an aluminum alloy brake disc with wear-resistant SiC particle reinforced aluminum matrix composites (SiC/Al) brazed on its surface is a promising technical opportunity.