Mechanical and tribological performance of a hybrid MMC coating deposited on Al–17Si piston alloy by laser composite surfacing technique. Issue 13 (13th February 2018)

• Record Type: Journal Article
• Authors: Quazi, M. M.; Ishak, M.; Arslan, A.; Fazal, M. A.; Yusof, Farazila; Sazzad, B. S.; Nasir Bashir, M.; Jamshaid, M.
• Is Part Of: RSC advances. Volume 8:Issue 13(2018)
• Page Start: 6858
• Page End: 6869
• Publication Date: 2018-02-13
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c7ra08191j
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : The addition of graphite as solid lubricant has significantly reduced the friction coefficient and wear of a Ni–WC composite coating. 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 781 H v 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.