Parametric Study and Characterization of SiC—TiC—Al Composite Coatings Fabricated on Al 6061 Alloy by TIG Cladding Process
摘要
SiC—TiC—Al composite coatings were successfully deposited by preplacing paste of SiC, TiC and Al powder mixture on aluminum 6061 alloy substrate by TIG cladding process. The effect of process parameters on microstructure, microhardness and wear properties of the coatings was investigated by SEM and XRD, Vickers microhardness tester, and pin-on-disc type dry sliding wear tester respectively. The analysis demonstrated that the microstructure, microhardness and wear behaviour of the SiC—TiC—Al coatings were influenced by heat input, which was varied by different parametric combinations of current and scan speed during cladding. XRD result revealed the presence of Al, TiC and formation of compound such as Al4SiC4, which enhanced the microhardness values of the clad layers such that, the microhardness of the cladded surface was observed up to 168 HV0.05, which was more than three times that of the substrate material. The developed coatings showed up to 4 times less in the wear loss value; under sliding abrasive conditions compared to the uncoated Al 6061 alloy, which validated the composite coating as a suitable option for the components requiring wear resistance.