Influence of shot peening and hard chromium electroplating on the fatigue strength of 7050-T7451 aluminum alloy

Chromium electrodeposition is a technique for the production of functional coatings on engineering components. These coatings are extensively micro-cracked and present high level of hardness, resistance to corrosion and wear and low coefficient of friction. In this paper the shot peening influence o...

Full description

Saved in:
Bibliographic Details
Published in:International journal of fatigue 2007-07, Vol.29 (7), p.1282-1291
Main Authors: Carvalho, A.L.M., Voorwald, H.J.C.
Format: Article
Language:English
Subjects:
Aluminum alloy
Applied sciences
Exact sciences and technology
Fatigue
Hard chromium electroplating
Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology
Metallic coatings
Metals. Metallurgy
Production techniques
Residual stress
Shot peening
Surface treatment
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Chromium electrodeposition is a technique for the production of functional coatings on engineering components. These coatings are extensively micro-cracked and present high level of hardness, resistance to corrosion and wear and low coefficient of friction. In this paper the shot peening influence on the fatigue strength of aluminum 7050-T7451 alloy chromium electroplated, was investigated. The shot peening process was carried out to create residual stresses using ceramic and glass shots. A hard chromium electroplated coating of 100μm thickness was performed on the base material and the shot peened base material surfaces. S–N curves were obtained in axial and bending fatigue tests and compared with the 7050-T7451 aluminum alloy. In order to study the influence of residual stresses on fatigue life, the behavior of compressive residual stress field was measured by an X-ray tensometry. An increase in the axial fatigue strength of 25% and 50% of ceramic and glass shots, respectively, was observed. The lower performance in fatigue life for ceramic-shot peening may be attributed to higher surface damage, as a consequence of the overpeening intensity performed. However, in bending fatigue the behavior was practically equivalent for both processes. Fracture surface analysis by scanning electron microscopy was used to observe crack origin sites from shot peened and chromium electroplated samples.
ISSN:0142-1123
1879-3452
DOI:10.1016/j.ijfatigue.2006.10.003