Fabrication of Cu-Sn-Ni /SiC FGM for Automotive Applications: Investigation of its Mechanical and Tribological Properties

The objective of this research is to fabricate a functionally graded Cu/SiC composite (Ø_out100 × Ø_in85 × 100 mm) using a horizontal centrifugal casting technique and to examine its mechanical and dry sliding wear characteristics. Microstructure of the composite was observed at outer (1 mm), middle (8 mm) and inner (14 mm) regions using a metallurgical microscope and results showed that the inner region had a high concentration (35%) of reinforcement particles compared to the other two regions. Mechanical properties were tested along the radial direction of the composite and results showed that maximum tensile strength and hardness were found to be 341 MPa and 280 HV respectively, at the inner region of the composite. Fractograpy examination revealed that the outer and inner regions were fractured by ductile and brittle modes of failures, respectively. The dry sliding wear tests were performed only at the inner region of the composite with selected parameters of load (10–30 N), sliding distance (500–1500 m) and sliding velocity (1–3 m/s) using a pin-on-disc tribometer. Analysis of variance and signal-to-noise ratio were used to study the effects of parameters on the wear rate of the composite and it was found that the load (54%) had highest influence followed by sliding distance (18.2%) and sliding velocity (3.7%). Worn surfaces were observed by a scanning electron microscope and it was confirmed that mild wear, severe plastic deformation, ploughing, delamination and wear debris were important wear mechanisms at different sliding conditions. Hence, this composite is suggested for use in bearings and bushes application, where the wear resistance is a primary consideration.