Effect of ball-burnishing on surface integrity and fatigue behaviour of 7175-T6 AA

Abstract

The burnishing process was performed using different feed rates, rotational speed and penetration depth parameters to alloy Al 7175-T6. Surface roughness, fatigue life and hardness of the samples were determined. Microstructural examinations of the samples were performed. In the surface roughness measurements, occurred a linear increase in proportion to the increasing feed rate. The increase in the penetration depth affected negatively the surface roughness. Significant increases were acquired in the fatigue life of the burnished samples. The hardness values of the burnishing samples are higher than the hardness value of the base material. The rotational movement of the steel ball during the burnishing process were been caused the aspect ratio of the grains in the microstructure to change.

Examining The Phase Formation of Aging and Shallow Cryogenic Process Applied to Aluminum Alloys with Thermal Analysis

“…In general, the aging process of ageable aluminum alloys begins with solution heat treatment between 550-400 C and natural aging at room temperature after quenching. The purpose of the aging heat treatment is to ensure the formation of a new phase from a supersaturated solid phase under the influence of time and temperature [4][5][6][7]. It was discovered by Cina in the 1970s that the heat treatment known as Retrogression and Re-Aging (RRA), that is, re-solution and re-aging, increases both the strength and corrosion crack resistance in 7xxx series aluminum alloys.…”