Evaluation of hole expansion formability of high strength AA7075 alloy under varying temper conditions

Published

May 31, 2022

Author(s)

Dilip K. Banerjee, Kali Prasad, Abrar Salam Ebrahim, Krishnaswamy Hariharan, Uday Chakkingal

Abstract

There has been a widespread increase in the use of aluminum alloys in automotive industries for meeting ever-growing light-weighting requirements. However, edge formability is a critical manufacturing challenge that restricts their widespread use. Edge formability of sheet metal is determined using a hole expansion test (HET) and is evaluated by the hole expansion ratio (HER). The present study investigates the effect of temper conditions on the edge formability of AA7075 alloy sheets. Hole expansion tests were conducted in different temper conditions such as W-temper (super saturated solid solution followed by water quenching), under aged (UA), and peak aged (PA). Two different hole preparation techniques, punching process and drilling process, were used to prepare samples with varying edge conditions. The results demonstrate that W-temper has the highest edge formability irrespective of hole edge conditions. Researchers have reported that uniaxial stress state prevails at the hole edge during the HET. Consequently, uniaxial tensile tests were conducted on these alloy sheet specimens and various tensile properties were determined to evaluate edge formability. Furthermore, microstructural and failure analysis of the failed specimens were performed to explain the deformation behavior during HET.

Proceedings Title

IOP Conference Series: Materials Science and Engineering

Volume

1238

Conference Dates

June 6-10, 2022

Conference Location

Lorient, FR

Conference Title

41ST INTERNATIONAL DEEP DRAWING RESEARCH GROUP CONFERENCE

Pub Type

Conferences

Download Paper

https://doi.org/10.1088/1757-899X/1238/1/012038

Local Download

Keywords

Stretch-flangeability, Hole expansion, Aluminium AA7075 alloy, Formability, Heat treatment

Citation

Banerjee, D. , Prasad, K. , Ebrahim, A. , Hariharan, K. and Chakkingal, U. (2022), Evaluation of hole expansion formability of high strength AA7075 alloy under varying temper conditions, IOP Conference Series: Materials Science and Engineering, Lorient, FR, [online], https://doi.org/10.1088/1757-899X/1238/1/012038, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=934155 (Accessed December 15, 2024)