Effect of heat treatment on notch sensitivity factor for aluminum alloy (AA 7075)‎

Dissertant

Abd al-Sahib, Imad Abd al-Husayn

Thesis advisor

al-Khazraji, Ahmad Nayif Ibrahim

University

University of Technology

Faculty

-

Department

Department of Electromechanical Engineering

University Country

Iraq

Degree

Master

Degree Date

2009

English Abstract

This study is concerned with the effect of heat treatment (precipitation hardening) on the notch sensitivity factor for aluminum alloy (7075).

Tests were conducted on smooth un- notched specimens and on three configurations of specimens which had external circumferential notches with notch radius of 0.5 mm, 0.7 mm, and 1 mm.

The alloy 7075 is hardened by artificial aging.

Mechanical tests are performed to determine the mechanical properties such as yield stress, ultimate tensile strength, hardness, and endurance limit of the alloy.

In addition to mechanical tests, microstructure examination and X-ray diffraction inspection are performed to study the variations in microstructure after heat treatment.

The fatigue tests are performed on different types of specimens.

The (S-N) equation was derived for each group to estimate the fatigue life under any applied stress amplitude.

The fatigue strength reduction factor (kf) and the notch sensitivity factor were calculated before and after heat treatment.

The results show that the fatigue strength reduction factor increases after heat treatment and with decreasing the notch radius.

The notch sensitivity factor increases with increasing the notch radius and also after heat treatment.

The increase percentage in notch sensitivity factor after the heat treatment for 1 mm notch radius is (22.616%) and this is grater than the increase percentage in notch sensitivity factor for all groups.

Main Subjects

Mechanical Engineering

Topics

• Mechanical properties
• Aluminum alloys

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-305068