Simon Stewart

PhD student

Department of Mechanical and Chemical Engineering

Heriot-Watt University

Edinburgh, EH14 4AS, UK

Tel:       +44 (0) 131 451 3779

Fax:      +44 (0) 131 451 3129

E-mail S.H.Stewart@hw.ac.uk

 

Background:

Qualifications: B.Eng. (Hons.) in Mechanical Engineering with Computer Aided Engineering – Heriot-Watt University 2000

 

Research Interests:

Brief summary of PhD project

Experimental investigation into the post-treatment of thermal spray coatings in high stress applications.  Thermal spray coatings studied were a Functional Graded WC-NiCrBSi coating system and a WC-12%Co coating; both deposited using the JP5000 HVOF deposition process.  Two types of post-treatment processes were applied to the coatings: Hot Isostatic Pressing (HIPing) and Vacuum heating.  Rolling Contact Fatigue (RCF) tests were performed using a modified four-ball tribometer under various tribological conditions.  The aim of the investigation was to potentially improve the performance of thermal spray coatings in high stress applications by optimising the microstructure through variation in post-treatment parameters.  Hence, the coatings could be tailored towards applications in hostile conditions ranging from the automotive industry to aerospace sectors.

 

Publications:

2004

1.      S. Stewart, R. Ahmed, and T. Itsukaichi “Contact Fatigue Failure Evaluation of Post-treated WC-NiCrBSi Functionally Graded Thermal Spray Coatings”, Surface and Coatings Technology, Submitted 2003, In print.

 

  1. S. Stewart, R. Ahmed, and T. Itsukaichi “Rolling Contact Fatigue of Heat-treated WC-NiCrBSi Thermal Spray Coatings”, Wear, Submitted 2003, In print.
  2. R. Ahmed, S. Stewart, V. Stoica, T. Itsukaichi, “Influence of post-treatment on the tribomechanical properties of cermet coatings, International Thermal spray Conference (ITSC2004), Osaka, Japan, ISBN 3-87155-792-7, 2004.

2003

1.      S. Stewart and R. Ahmed, “Contact Fatigue Failure Modes in Hot Isostatically Pressed WC-12%Co Coatings”, Surface and Coatings Technology, 172, 204-216, 2003.

 

  1. S. Stewart, R. Ahmed, T. Itsukaichi and S. Tobe, “Rolling Contact Fatigue of Hot Isostatic Pressed WC-NiCrBSi Thermal Spray Coatings”, Advancing the Science and Applying the Technology, International thermal spray conference, Florida, USA, 1351-1359, 2003.

 

2002

 

S. Stewart and R. Ahmed, “Rolling Contact Fatigue of Surface Coatings-a Review”, Wear, 253, 1132-1144, 2002.

 

Presentation(s)

Rolling Contact Fatigue of HIPed Thermal Spray Coatings

 

Other Interests:

Squash, skiing, golf