Microstructures of Stainless Steels Exhibiting Reduced Friction and Wear After Implantation with Ti and C

Abstract

ABSTRACTImplantation of Ti and C into stainless steel discs of Types 304, 15–5 PH, Nitronic 60 and 440C has previously been reported to reduce wear depths by up to ∼ 85% and friction by ∼ 50% in unlubricated pin-on-disc tests. Our earlier studies relating microstructure to friction and wear results in Type 304 are first summarized; these indicate that the improvements in the surface mechanical properties are due to an amorphous surface layer, similar to the amorphous layer observed in pure Fe implanted with Ti and C. We have now examined the other three implanted steels and found similar amorphous layers. These results strongly suggest that the amorphous surface alloy is responsible for reduced friction and wear in all the steels.