The Effect of Cold Spray Coating on Fatigue Life of Magnesium Alloy, AZ31B

Wrought magnesium alloys are considered attractive candidates for structural members in automotive and aerospace industries due to their high specific strength. Although new processes have helped to produce high purity magnesium alloys with higher resistance to corrosion, these alloys still need pro...

Full description

Bibliographic Details
Main Author: Mahmoudi-Asl, Hassan
Language:en
Published: 2011
Subjects:
Online Access:http://hdl.handle.net/10012/6370
id ndltd-WATERLOO-oai-uwspace.uwaterloo.ca-10012-6370
record_format oai_dc
spelling ndltd-WATERLOO-oai-uwspace.uwaterloo.ca-10012-63702013-01-08T18:55:05ZMahmoudi-Asl, Hassan2011-10-27T19:48:36Z2011-10-27T19:48:36Z2011-10-27T19:48:36Z2011-10-19http://hdl.handle.net/10012/6370Wrought magnesium alloys are considered attractive candidates for structural members in automotive and aerospace industries due to their high specific strength. Although new processes have helped to produce high purity magnesium alloys with higher resistance to corrosion, these alloys still need protection against corrosion when they are used in aggressive environments. Cold spray coating is one of the protective methods that are employed for this purpose. The similarity between cold spray coating and shot peening process poses the question whether cold spray coating can improve the fatigue strength in addition to providing corrosion protection. The objective of this research is to answer this question for the specific case of the coating of wrought magnesium alloy AZ31B with aluminum powder. This study comprises two parts. The first part characterises the residual stress induced by cold spray coating. This investigation employs both numerical and experimental methods. For the numerical study, the cold spray coating process has been simulated via ANSYS software classic package. The numerical results have been compared to experimental results from X-Ray Diffraction (XRD) stress measurement of a coated sample. For the second part of this research, the fatigue strength of as received, stress relieved, and stress relieved/coated specimens have been compared. Three groups of AZ31B specimens have been prepared and tested by rotating bending machine and their S-N curves have been prepared. Comparison of the results reveals that there is a considerable loss in fatigue strength of as received specimens after stress relief. This is due to the removal of compressive residual stress in the raw material induced by the extrusion process. Also, comparison of S-N curves of stress relieved and stress relieved/coated specimens shows fatigue life improvement after cold spray coating. The maximum improvement is 49 percent in the load of 120 MPa and the endurance limit has improved 9 percent.enFatigueCold Spray CoatingMagnesiumAZ31BThe Effect of Cold Spray Coating on Fatigue Life of Magnesium Alloy, AZ31BThesis or DissertationMechanical and Mechatronics EngineeringMaster of Applied ScienceMechanical Engineering
collection NDLTD
language en
sources NDLTD
topic Fatigue
Cold Spray Coating
Magnesium
AZ31B
Mechanical Engineering
spellingShingle Fatigue
Cold Spray Coating
Magnesium
AZ31B
Mechanical Engineering
Mahmoudi-Asl, Hassan
The Effect of Cold Spray Coating on Fatigue Life of Magnesium Alloy, AZ31B
description Wrought magnesium alloys are considered attractive candidates for structural members in automotive and aerospace industries due to their high specific strength. Although new processes have helped to produce high purity magnesium alloys with higher resistance to corrosion, these alloys still need protection against corrosion when they are used in aggressive environments. Cold spray coating is one of the protective methods that are employed for this purpose. The similarity between cold spray coating and shot peening process poses the question whether cold spray coating can improve the fatigue strength in addition to providing corrosion protection. The objective of this research is to answer this question for the specific case of the coating of wrought magnesium alloy AZ31B with aluminum powder. This study comprises two parts. The first part characterises the residual stress induced by cold spray coating. This investigation employs both numerical and experimental methods. For the numerical study, the cold spray coating process has been simulated via ANSYS software classic package. The numerical results have been compared to experimental results from X-Ray Diffraction (XRD) stress measurement of a coated sample. For the second part of this research, the fatigue strength of as received, stress relieved, and stress relieved/coated specimens have been compared. Three groups of AZ31B specimens have been prepared and tested by rotating bending machine and their S-N curves have been prepared. Comparison of the results reveals that there is a considerable loss in fatigue strength of as received specimens after stress relief. This is due to the removal of compressive residual stress in the raw material induced by the extrusion process. Also, comparison of S-N curves of stress relieved and stress relieved/coated specimens shows fatigue life improvement after cold spray coating. The maximum improvement is 49 percent in the load of 120 MPa and the endurance limit has improved 9 percent.
author Mahmoudi-Asl, Hassan
author_facet Mahmoudi-Asl, Hassan
author_sort Mahmoudi-Asl, Hassan
title The Effect of Cold Spray Coating on Fatigue Life of Magnesium Alloy, AZ31B
title_short The Effect of Cold Spray Coating on Fatigue Life of Magnesium Alloy, AZ31B
title_full The Effect of Cold Spray Coating on Fatigue Life of Magnesium Alloy, AZ31B
title_fullStr The Effect of Cold Spray Coating on Fatigue Life of Magnesium Alloy, AZ31B
title_full_unstemmed The Effect of Cold Spray Coating on Fatigue Life of Magnesium Alloy, AZ31B
title_sort effect of cold spray coating on fatigue life of magnesium alloy, az31b
publishDate 2011
url http://hdl.handle.net/10012/6370
work_keys_str_mv AT mahmoudiaslhassan theeffectofcoldspraycoatingonfatiguelifeofmagnesiumalloyaz31b
AT mahmoudiaslhassan effectofcoldspraycoatingonfatiguelifeofmagnesiumalloyaz31b
_version_ 1716573889106018304