Volume fraction effect of stainless steel on microstructure, interface, corrosion and wear behavior of stainless steel/aluminum bimetal composites

Abstract

304 stainless steel (SS)/A356 aluminum bimetal composites were manufactured by vacuum-assisted melt infiltration casting successfully. SS chips with different volume fractions of 35%, 50%, 60%, and 65% were used in a composite structure. Low-cost, environmentally friendly production was achieved by using chips as reinforcing material. Dry sliding ball-on-disc tests were performed against Al(4)O3 ball under a load of 10 N. Potentiodynamic polarization analysis was carried out in 3.5% NaCl solution. theta (Fe4Al13) and eta (Fe2Al5) phases developed at the SS/Al interfaces. Abrasive and adhesive wear predominated worn surfaces, whereas galvanic and pitting corrosion mechanisms originated during potentiodynamic polarization tests. Lower volume fractions of SS chips resulted in microploughing, while their higher amounts caused microcutting during sliding. Moreover, the samples containing 60% and 65% SS failed in the corrosion tests due to the lack of passivation. The most suitable SS ratio was determined to be 50%, considering microstructural, interfacial, tribological, and anti-corrosion features of SS/Al bimetal composites.