Effect of thickness on Fatigue Crack Growth of Aluminium alloys

Abstract

The effect of thickness on fatigue crack growth has been investigated for aluminium alloys such as a high-strength aluminium alloy (A7075-T6), a medium strength alloy (A6063-T6), and A2024-T351. The fatigue tests were conducted using Instron 8801 fatigue testing machine on all those materials with thicknesses of 12.7, 15.8, and 20 mm. All specimens were undergoing finishing process on the surface. These tests were run under constant amplitude load for each different thickness and materials. Fatigue crack growth specimen made of A2024-T351 and A6063-T6 aluminum alloys with thickness of 12.7 mm were higher than specimen made of A7075-T6 aluminum alloy with thickness of 20 and 12.7 mm and A6063-T6 aluminum alloy with thickness of 15.88 mm. It is concluded that fatigue crack growth decreases significantly with increasing thickness, and the crack initiates very fast on surface material.