EFFECT OF POLISHING ON THE FATIGUE RESIS TANCE AND RESIDUAL STRESSES FO R THE SHOT PEENED OF 7075 T6 ALUMINUM ALLOY

Al-Khazraji, Ahmed Naif Ibrahim; Al-Shabbani, Rasool Mahdi Awwan

doi:10.30772/qjes.v10i4.491

	EFFECT OF POLISHING ON THE FATIGUE RESIS TANCE AND RESIDUAL STRESSES FO R THE SHOT PEENED OF 7075 T6 ALUMINUM ALLOY
Al-Qadisiyah Journal for Engineering Sciences
Volume 10, Issue 4, December 2017, Pages 420-430 PDF (976.96 K)
Document Type: Research Paper
DOI: 10.30772/qjes.v10i4.491
Authors
Ahmed Naif Ibrahim Al-Khazraji^* ; Rasool Mahdi Awwan Al-Shabbani
The University of Technology, Department of Mechanical Engineering, Iraq
Abstract
Aluminum alloy (7075-T6) is widely used in various industries in parts of aircraft, automobiles and other mechanical applications. It is known that the process of the shot peening leads to an increase in the value of residual stresses, which prolong the fatigue life. However, during surface peening of various metals, including aluminum alloy (7075-T6) used in this work, these surfaces become rough where the places to concentrate the stresses, which will fail when exposed to different dynamic stresses. This paper presents an study on the effect of polishing (the roughness surface induced from shot peening process) on endurance limit and residual stresses result by shot peening. In this paper was used three values of surface roughness (1.5, 3, and 5) μm. The obtained results show that the maximum increasing in endurance limit was (53%) at low roughness compared with as received and increasing value roughly to (27%) compared with alloy after shot peening. . The residual stresses gradually increased (-222.735, -229.602, -250.900) Mpa when the roughness surfaces decreased (5, 3, 1.5) μm respectively.
Keywords
polishing Shot peening; Residual stress; Endurance limit; Aluminum alloy (7075-T6)

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