Friction and abrasion resistance of cast aluminum alloy-fly ash composites

Abstract

The abrasive wear properties of stir-cast A356 aluminum alloy-5 vol pct fly ash composite were tested against hard SiC p abrasive paper and compared to those of the A356 base alloy. The results indicate that the abrasive wear resistance of aluminum-fly ash composite is similar to that of aluminum-alumina fiber composite and is superior to that of the matrix alloy for low loads up to 8 N (transition load) on a pin. At loads greater than 8 N, the wear resistance of aluminum-fly ash composite is reduced by debonding and fracture of fly ash particles. Microscopic examination of the worn surfaces, wear debris, and subsurface shows that the base alloy wears primarily by microcutting, but the composite wears by microcutting and delamination caused by crack propagation below the rubbing surface through interfaces between fly ash and silicon particles and the matrix. The decreasing specific wear rates and friction during abrasion wear with increasing load have been attributed to the accumulation of wear debris in the spaces between the abrading particles, resulting in reduced effective depth of penetration and eventually changing the mechanism from two-body to three-body wear, which is further indicated by the magnitude of wear coefficient.

Abrasive wear behaviour of aluminium hybrid nanocomposites produced by ultrasonication assisted casting method

“…Increasing the rotational speed from 400 rpm to 600 rpm increases heat generation in the nugget region, which leads to more softening of the Al matrix due to over aging. The high heat generation induced the matrix softening, which resulted in increased wear rate at higher speeds [23,32].…”

“…Most of the works used conventional fabrication methods like stir casting or powder metallurgy for the manufacturing of the composites. Generally, reinforcement powders used in these works are of micrometer size [20][21][22][23][24]. Only very few works reported in the area of abrasive wear studies have used Al hybrid composites.…”

Tribological Properties of Aluminium 2024 Alloy Beryl Particulate MMC's

“…Further, as the percentage of reinforcement increases, the coefficient of friction of the composite decreases. [17] Figure 9 and 10 shows the Scanning Electron Micrograph (SEM) of worn surfaces of as-cast Al2024 alloy and Al2024-6 wt.% Beryl composite respectively. The mechanism of material removal during wear process of the Al2024 alloy was by plastic deformation and gouging.…”

Thermal Properties of Aluminium-Fly Ash Composite

“…Hence, composites with fly ash as reinforcement are likely to overcome the cost barrier for wide spread applications in automotive and small engine applications. It is therefore expected that the incorporation of fly ash particles in aluminium alloy will promote yet another use of this low-cost waste by-product and, at the same time, has the potential for conserving energy intensive aluminium and thereby, reducing the cost of aluminium products [1][2][3]. In the present work, fly-ash which mainly consists of refractory oxides like silica, alumina, and iron oxides is used as reinforcing phase.…”