Prediction of fracture behavior during the small punch test for aluminum alloy 6061

Article type: Research Article

Authors: Pham, Hang Thi^a;

Affiliations: [a] Thuyloi University, Faculty of Mechanical Engineering, Hanoi, Vietnam

Correspondence: [*] Corresponding author: Hang Thi Pham, Faculty of Mechanical Engineering, Thuyloi University, No. 175 Tay Son, Dong Da, Hanoi, Vietnam. E-mail: pthang@tlu.edu.vn

Abstract: The aim of this work is to investigate fracture mechanical characteristic of aluminum alloy 6061 by the small punch test in low range of deformation rate. The results of the force-displacement of the puncher curve and scanning electron microscope observation of fracture surface of deformed specimen are used to discuss fracture toughness of the material. The obtained results show that the influence of the displacement rate on the force - displacement of the puncher cannot be clearly seen. The mechanism of fracture properties of aluminum alloy 6061 is quite complicated and there is a large difference between the fracture surface of the top side which contacts with the punch head and the fracture surface of the bottom side. The bottom side shows not only crack in the direction perpendicular to the applied external force but also crack along the direction of the crack ring. The local ductile fracture might dominate to induce the initial crack due to shear stress. Then, the crack spreads via the direction perpendicular to the applied external force as well as along the direction of the crack ring without any dimples. Meanwhile, tensile stress plays an important role in breaking the specimen in half.

Keywords: Aluminum alloy, fracture properties, mechanical testing, small punch test

DOI: 10.3233/SFC-240005

Journal: Strength, Fracture and Complexity, vol. Pre-press, no. Pre-press, pp. 1-10, 2024