Fabrication and Properties of Metal Matrix Composites for Automotive Brake Caliper Applications

Metal matrix composites were produced by the PRIMEX™ pressureless metal infiltration process. Properties of the composites were determined as a function of particulate loading, filler type, alloy chemistry, and test temperature. Using the property data, a generic brake caliper bridge geometry was designed and modeled. The results of the modeling suggested that composite caliper bridges can be equivalent in stiffness to ductile iron components at only 43% of the mass, and equivalent in stiffness to aluminum components at only 60% of the mass. In addition, composites containing unreinforced regions (i.e., areas without ceramic particulates) were fabricated to facilitate drilling and tapping at attachment locations. The strength of the threads in these regions was evaluated and compared with thread strengths in iron, Al alloy, and monolithic metal matrix composite.