Numerical and experimental investigation on bonding behavior of cold sprayed porous WC-17Co particles onto different substrates

Abstract

Cold sprayed WC-Co metal matrix composite coatings have shown great potential in wear-resistance applications. This work aims to use experimental and numerical methods to clarify the deposition and particle-substrate bonding behavior of a single porous WC-17Co particle onto various substrates. To achieve this objective, porous WC-17Co particles were used as the feedstock; soft Al 2024 (Al alloy) and hard stainless steel 316 (SS) were used as the substrates. The experimental results revealed that brittle WC-Co particles tended to remain intact after depositing on a soft Al alloy substrate, but underwent serious fracture when impacting on a hard SS substrate. Further results indicated that the high energy dissipation and the consequent high stress concentration in the WC-Co particle was the main reason for inducing the particle fracture. In addition, two different mechanical interlocking mechanisms were identified during the WC-Co particle deposition process (namely WC reinforcement interlock and WC-Co particle interlock), dominating the particle-substrate bonding. A soft Al alloy substrate resulted in better interlocking than a hard SS substrate, thereby the corresponding particle bonding ratio was also much higher.