Near-Absolute Net-Shape Processing of Reinforced Aluminum Castings for Brake Calipers

Near-absolute net-shape processing utilizing MIT/MMCC's high rate pressure infiltration casting process for manufacturing brake calipers is proposed, with Allied-Signal providing design and mechanical testing support gratus. The first objective is to demonstrate the ability to manufacture near-absolute net-shape brake calipers meeting TACOM's design requirements, including a weight reduction for calipers of 60%, for the DEMO III PLS (Palletized Loading System) test vehicle. The second objective is to optimize alumina reinforced A1 alloy systems and to generate a preliminary data base on the optimized system for brake calipers. Over 1,200 net-shpate mechanical test specimens will be manufactured for the materials system optimization and preliminary data base studies with minor machining required, thus demonstrating the near-absolute net-shape capability of the process and a machining cost saving of $60,000. MMCC will perform metrology on each specimen and tooling wear and stability studies to evaluate the near-absolute net-shape capability of the process. MMCC will also evaluate the design of mold tooling for maximum re-use. A third objective is to manufacture four prototype calipers. The final objective is to develop a process cost model for brake calipers. Anticipated Benefits: A highly precise casting method capable of lower costs than die casting or squeeze casting will be developed for reinforced as well as unreinforced castings. A 60% reduction in unsprung weight of brake calipers for army trucks will become available. Such weight reductions will be attractive for commercial automotive applications, including conrods, wrist pins, piston crowns, diesel head inserts, rocker arms, "H" arms, "A" arms as well as brake calipes and disk brakes.