Effect of Interlayers on Mechanical Properties of Aluminium Casting over Stainless Steel Pipe for Heat Exchanger Applications

摘要

This paper aims to produce Al casting over SS pipe by introducing Cd, Cu, Ag and brass interlayer and to study their effect on the interface bonding between aluminium (Al) and stainless steel (SS). Castings were produced by novel thermocol moulding method and their mechanical properties and metallurgical characteristics were studied. The shear punch test was conducted to evaluate the bond strength of Al-SS bimetallic castings (BmC). Without interlayer, castings showed bond strength of 5.21 MPa, whereas Cd and Cu interlayered BmC showed bond strength of 91.2 MPa and 112.45 MPa, respectively. Ag and brass interlayered BmC showed less effect on bond strength. Interlayers with low melting point and high solubility showed good metallurgical bonding than the interlayers with the high melting point. Eutectic formation of Cd with Al and diffusion of Cu into Al led to the formation of a better metallurgical bond. Hence, they might be used as a potential candidate material for applications like lightweight, hot corrosive fluid and chemical transports.