Scale-dependent wetting behavior of bioinspired lubricants on electrical discharge machined Ti6Al4V surfaces

The relationships between the geometric features of material surfaces and topographically related phenomena, such as wetting, change with the scale of observation. In these studies, multiscale analyzes allow characterizing the relationships between electrical discharge machining parameters, complex surface topographic structures and contact angles. Importantly, it was possible to indicate the best scales for observing the phenomena of lubricant flow on electro-discharged surfaces and to identify key geometric parameters of the surface affecting the contact angle. This paper proposes scale-dependent contact angle analyzes of electro-discharge machined Ti6Al4V alloy for biomedical implant applications. Liquids imitating synovial fluid in joints were used as lubricants. The research focuses on comparing the impact of discharge energy on surface microtexture, chemical composition, contact angle and surface free energy. The analysis of the lubrication behavior on micro-textured surfaces in contact mechanics co-determines the tribological properties. The research results confirm the effectiveness of modeling the specific wettability of implant surfaces with bioinspired lubricants.