Quazi M M, Ishak M, Arslan A, Fazal M A, Yusof Farazila, Sazzad B S, Nasir Bashir M, Jamshaid M
Department of Mechanical Engineering, Faculty of Engineering, Universiti Malaysia Pahang Pekan 26600 Malaysia
Department of Mechanical Engineering, Faculty of Engineering, University of Malaya 50603 Kuala Lumpur Malaysia.
RSC Adv. 2018 Feb 13;8(13):6858-6869. doi: 10.1039/c7ra08191j. eCollection 2018 Feb 9.
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 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.
激光复合堆焊（LCS）是一种光子驱动的制造技术，可用于在较软的钛/铝/镁合金上沉积混合金属基复合涂层（HMMC），以提高其摩擦学机械性能。LCS具有更高的方向性、局部微观结构细化以及涂层与基体之间更高的冶金结合等优点。当前的研究通过在5%至15%重量百分比之间改变石墨浓度，对通过LCS在铝硅活塞合金上沉积的基于固体润滑剂的镍钨碳化物涂层进行了摩擦学机械评估和表征。使用销盘摩擦磨损试验机研究了LCS样品的摩擦学行为。结果表明，在基于石墨的HMMC涂层进行LCS处理后，铝硅过共晶活塞合金的表面硬度、磨损率和摩擦系数均得到改善。含5 wt%石墨的镍钨碳化物涂层获得了781的最大表面硬度。在干滑动条件下，铝硅合金的摩擦系数从0.47降低到0.21。摩擦系数的降低归因于形成了可剪切的转移层，该转移层防止了分层并减少了粘附、磨损和疲劳裂纹。
