Micromechanical behavior study of forged 7050 aluminum alloy by microindentation: Fid-Bau Portal

Micromechanical behavior study of forged 7050 aluminum alloy by microindentation

Li, Jiang / Li, Fuguo / Xue, Fengmei / Cai, Jun / Chen, Bo

Highlights ► Microindentation study of forged 7050 aluminum alloy was conducted. ► Damage accumulated in the test process and microhardness showed a size effect. ► Simulation verified the microindentation constitutive equations.

Abstract In order to investigate the micromechanical behavior of forged 7050 aluminum alloy with different heat treatment conditions, microindentation experiments of 7050-T7451 and 7050-T7452 were performed with various maximum indentation loads and various loading speeds. A non-destructive instrumental approach was applied to indicate mechanical properties such as Young’s modulus E, microhardness H, initial yield stress σy and strain hardening exponent n using the available experimental indentation P–h curves from the microindentation tests. The experimental results revealed that loading speed exerted little influence on measurement of E and H. E decreased rapidly because of the indentation damage accumulation, and H decreased with the increase of indentation load, which showed strong indentation size effects. Dimensionless functions П 1 and П 2 were used to describe the plasticity constitutive equations and revealed that the heat treatment conditions influenced the micromechanical properties. H and σy tested from the microindentation of 7050-T7451 were higher than those of 7050-T7452, and microindentation plasticity constitutive equations were obtained by using Hookean elastic and power-law plastic stress–strain relation equations, which were verified by finite element method (FEM) simulation well.