Preparation and properties of lead-free copper matrix composites by electroless plating and mechanical alloying

Abstract

Based on the concept of green design and development, FeS/Cu–Bi lead-free copper matrix composites were prepared by using FeS and Bi powder as lubricating phase to replace the lead in CuPb alloy. Surface modification of FeS powder by electroless plating and mechanical alloying of mixed powder by high-energy ball milling are effective strategies for preparing lead-free copper matrix composites. The effects of surface modification and mechanical alloying on the mechanical and tribological properties of the materials are studied. Results show that electroless nickel plating improves the mechanical locking and metallurgical bonding between mixed powder particles; enhances the interface bonding between FeS particles and copper matrix; and increases the hardness, impact toughness, and crushing strength by 29.7%, 19.4%, and 13%, respectively. The density and hardness of the composite prepared by electroless nickel plating combined with mechanical alloying increases by 11.4% and 40.6%, respectively, average friction coefficient decreases from 0.44 to 0.28, and wear rate decreases by 62%. Electroless plating and mechanical alloying reduce the microploughing and material transfer on the worn surface of the composites, and the abrasive wear and adhesive wear are remarkably improved.