Mechanical and tribological performance of a hybrid MMC coating deposited on Al–17Si piston alloy by laser composite surfacing technique
Document Type
Article
Publication Date
1-1-2018
Abstract
Laser composite surfacing (LCS) is a photon driven manufacturing technology that can be utilized for depositing hybrid metal matrix composite coatings (HMMC) on softer Ti/Al/Mg alloys to enhance their tribo-mechanical properties. LCS offers the advantages of higher directionality, localized microstructural refinement and higher metallurgical bonding between coating and substrate. The current research presents the tribo-mechanical evaluation and characterization of solid lubricant based Ni-WC coatings deposited by LCS on Al-Si piston alloy by varying the concentration of graphite between 5-to-15-weight percentage. The tribological behavior of LCS samples was investigated using a ball-on-plate tribometer. Results indicate that the surface hardness, wear rate and friction coefficient of the Al-Si hypereutectic piston alloy were improved after LCS of graphite based HMMC coatings. The maximum surface hardness of 781Hv was acquired for the Ni-WC coating containing 5 wt% graphite. The friction coefficient of Al-Si under dry sliding conditions was reduced from 0.47 to 0.21. The reduction in the friction coefficient was attributed to the formation of a shearable transfer layer, which prevented delamination and reduced adhesion, abrasion and fatigue cracking.
Keywords
Friction coefficients, Hybrid metal matrix composites, Manufacturing technologies, Mechanical evaluation, Metallurgical bonding, Microstructural refinement, Tribological behaviors, Tribological performance
Divisions
fac_eng
Funders
University of Malaya Research Grant (UMRG, RP035A-15AET),University Malaysia Pahang (Grant No. RDU150378)
Publication Title
RSC Advances
Volume
8
Issue
13
Publisher
Royal Society of Chemistry