Morphology of Surface Integrity as Effect of Cold Forging of Aluminum Alloy

Abstract

ABSTRACT Aluminum and its alloys represent a common raw material for components released through a cold machining routine (i.e., forging, cold heading, and rolling processes). They offer easy manufacturing and high plastic strength, together with light weight, long life span, and easy recycling and are heavily used in the transport industry (P. M. G. P. Moreira, et al. (1), Theoretical and Applied Fracture Mechanics, 50, pp 81–91, 2008; H. Yoshimura and K. Tanaka (2), Journal of Materials Processing Technology, 98, pp 196–204, 2000). However, during processing, the sample–tool interfaces can generate sticking mechanisms that result in an increase in friction values and high wear rates, leading to irreversible damage to the workpiece surface. The surface morphology provides characteristics that allow detection of the damage amplitude. The hard contact between asperities causes nucleation and the formation of adhesive wear. The normal load and lubrication conditions may further affect the quantity of wear elements (A. Hase and H. Mishina (3), Tribology International, 42, pp 1684–1690, 2009). Optical nondestructive observations permit the detection of the quantity of wear elements as per material transfer from one side (specimen surface) to the other side (contactor surface). This article presents the mechanisms of the adhesive layer and material transfer that are directly proportional to the new roughness stature. A robust finite element method analysis was embedded to establish a relationship between time, plastic deformation, friction coefficients, and surface defects.