Sliding wear response of ultrasonic-assisted stir-squeeze cast Al-Zn(-Mg) alloy/ZrO_2p composite: wear mechanism and subsurface deformation

Abstract

The character of hard ZrO2p in dry sliding wear of Al-Zn(-Mg) alloy was investigated in the cast and heat-treated conditions using pin-on-disc wear tester at fixed sliding speed (3.5 m/sec) and varying applied pressure (0.5-2.125 MPa), giving special accentuation on the response parameters such as seizure resistance, wear rate, and bulk temperature rise. Hardness behavior was also studied for the same concerned materials in accordance with ASTM standards. The composites exhibited enhanced hardness, wear and seizure resistance, and greater temperature rise over the alloy. Indeed, the wear rate at preliminary stages increased with increasing applied pressure up to a transition limit beyond which it upsurged abruptly to greater value at the seizure pressure. Heat treatment also significantly improved the hardness, and resistance to wear and seizure. Amongst, heat-treated composite embedded with 4% ZrO2p yielded the highest hardness of 89 HRB and seizure pressure of 2.125 MPa respectively. The deformation in the subsurface was examined in terms of microhardness variation along the depth perpendicular to the worn surface. It was detected that the presence of ZrO2p not only enhanced the seizure resistance but also effectively hampered the extent of subsurface deformation at the seizure. The wear mechanism was prevalently governed through the establishment of mechanically mixed layer (MML), oxide layer, cracking, and deformed subsurface.

Dry sliding wear response of aluminium matrix composites (AMCs): a critical review

“…However, the material loss was less with increasing reinforcement TiB 2 concentration. Singh et al [125] examined the influence of varying applied pressure (0.5 to 2.125 MPa) dry sliding wear behavior of Al alloy composites reinforced with 2%-4% ZrO 2 particle and found that the wear rate initially increased with increasing applied pressure and eventually increased suddenly to a very high value when the materials got seized at higher pressures. The variation in the wear rate of materials in different conditions can be seen in figure 6.…”

“…Because of mechanical joining/weld Figure 6. Wear rate variation in Al alloy and 2 and 4% ZrO 2 reinforced composite materials under heat-treated (HT) and as-cast (AC) conditions with respect to normal pressure (s: seizure) [125].…”

Effect of Different Ceramic Reinforcements on Microstructure, Mechanical Properties and Tribological Behaviour of the Al6082 Alloy Produced by Stir Casting Process

“…Thus, there is a need to study the wear characterisation of AMCs under different conditions. Several investigations have focused on the abrasive wear and sliding behaviour of AMCs [33][34][35][36][37][38][39][40][41][42][43][44][45]3,7]. in contrast, very few studies have focused on the dry sliding wear behaviour of AMCs at high temperatures.…”