Effect of Pin Geometry and Orientation on Friction and Wear Behavior of Nickel-Coated EN8 Steel Pin and Al6061 Alloy Disc Pair

Abstract

Most mechanical systems (in particular, gear transmission system) undergo relative motion which results in increased friction phenomenon (friction coefficient, stresses, and wear rate) and thereby results in loss of efficiency. Mechanical parts undergo relative motion in different geometry configurations and orientations that induce a different state of stress as a result of friction. Till date, attempts are being made to minimize the friction with full sphere pin geometry configuration. The present work focused to reduce the frictional and wear rate, and experiments are conducted with tribo-pairs. i.e., nickel-coated pin surface slide against Al6061 alloy disc. The friction studies are carried out at different loads and geometries of pin surfaces (sphere and hemisphere configured at different orientations such as full sphere and hemisphere configured at 0°, 45°, and 90°) to induce different stress states with reference to sliding directions. Change in the geometry of EN8 pin material and their orientation with reference to sliding direction resulted in a different state of stress. The resulting stress levels were examined under the scanning electron microscope, which revealed the mechanisms of adhesion, abrasion, and extrusion. At a lower magnitude of orientation and load, the extent of asperity breaking lessens and material removal from pin surface decreases. Abrasion wear mechanism was observed corresponding to full sphere configuration on Al 6061 disc, whereas adhesive wear mechanisms are seen with hemisphere pins. The amount of aluminum transfer on pin surface with a hemisphere pin is comparatively more than that of full sphere configuration. At a lower magnitude of state of stress, the mechanism of sliding was dominated by the adhesion effect. At a higher level of state of stress, the mechanism of sliding was dominated by abrasion and extrusion.

Influence of Alloying Materials Al, Cu, and Ca on Microstructures, Mechanical Properties, And Corrosion Resistance of Mg Alloys for Industrial Applications: A Review

“…This is mostly caused by the development of a sizable stress concentration near a sizable number of second phases, − which may cause fractures to form and mechanical characteristics to deteriorate. Additionally, as the Cu concentration increases, agglomerates continuously surround the main Mg grains, which is predicted to diminish the tensile properties. − …”

Empirical Analysis of Multiwalled Carbon Nanotube Deposition for Enhancing Mechanical and Tribological Characteristics in Aluminium-Based Metal Matrix Composites

“…A MG-2000 high-speed, hightemperature pin-on-disc wear machine was put through wear testing in an unlubricated sliding environment at standard optimum temperature of 21 to 24°C with 50 to 60% relative humidity was maintained. An analogous wear method was followed by numerous researchers [44][45].…”

Studies of Al2219-SiC Composite Using Liquid Metallurgy: Effect of Mechanical and Wear Properties

“…The components subject to wear are mainly due to sliding action, abrasiveness, erosion, and corrosion. Extensive studies have been carried out to assess the Aluminium composites against various wear situations under varying environmental and tribological conditions [3]. Graphite, silicon carbide, and aluminium oxide constitute the most used reinforcing materials in these composites.…”