Ceramic protection plates brazed to aluminum brake discs

Aluminum alloys are light-weight and one of the most interesting material solutions to optimize the strength/weight ratio to reduce car weight; however they are also relatively soft and therefore cannot be used for intensive wear applications. We developed an aluminum alloy part combined with hard and wear-resistant A1203-based ceramic plates on the surface for demanding mechanical parts for automotive industry such as disc brakes. Tribological tests of various engineering ceramic materials were performed in order to find a ceramic material with a combination of coefficient, wear resistance and thermal energy dissipation for the car brakes. A1203-based ceramic showed promising properties, as well as being cost effective. Two different approaches to braze ceramic on aluminum were investigated. A two-step brazing process using Cu-Sn-Ti-Zr filler alloy and a single step ultrasonic active soldering with Sn-Ag-Ti filler alloy. Larger areas of aluminum could be covered with a segmented brake design in which many ceramic plates were joined surface. Comparable tribological properties to those of the bulk ceramic material were achieved. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.