Workshop – Wear, Tribology and Tribo-materials

 

Tribological Issues in the Automotive Industry

Ahmet T. Alpas

NSERC/ General Motors of Canada Industrial Research Chair

Mechanical, Automotive and Materials Engineering

University of Windsor, Windsor , Ontario, Canada, N9B 3P4

 

The development of lightweight internal combustion engines represents one of the most significant technological advances in automotive technology. By reducing vehicle weight and improving packaging, lightweight aluminium engines help to diminish emissions and improve fuel economy. Further developments in lightweight engine technology depend on the effective use of Al-Si alloys: In order to increase the use of aluminium alloys, tribological problems associated with these alloys must be solved. Scuffing and seizure under oil starvation conditions and durability problems during normal operation are among the notable issues. This talk will focus on the assessment of wear mechanisms in aluminium engines and their correlation with the laboratory tests. Contact mechanics of Al-Si surfaces, the microstructural changes that take place during different wear regimes will be discussed. Applications of novel characterization techniques including optical surface profilometery, and dual beam focussed ion beam imaging techniques in the assessment of surface damage will be discussed.

 

 

 

Corrosive Wear: Principles, Prevention, and Applications

M. Ziomek-Moroz

National Energy Technology Laboratory,

U.S. Department of Energy, Albany, OR, USA

 

Corrosive wear poses a significant economical problem in many industries. Many engineering materials are subject to corrosive wear in corrosive media, e.g., erosion-corrosion of components operated in corrosive slurries containing solid particles. Engineers must be able to incorporate corrosive wear prevention methods into their design. On the other hand, corrosive wear can be used as an innovative solution to some technological processes such as the chemical-mechanical planarization technique used in the semiconductor industry. This presentation will discuss the principles of corrosive wear and different approaches for corrosive wear prevention. In addition, this talk will address applications of corrosive wear to developing innovate solutions to industrial processes.

 

 

 

Metallurgy of High Chromium White Irons

K. F. Dolman

Weir Minerals Australia Ltd, Sydney, Australia

 

Large volumes of high-chromium white irons are used annually for the production of castings and hardfacing weld overlays to combat erosive and abrasive wear in mineral and chemical processing plants. The gap between hypoeutectic white cast irons, which originated in 1917, and hypereutectic CrC hardfacing weld deposits, which were developed many years later, has narrowed as the metallurgy of Fe-Cr-C alloys has become better understood. Hypereutectic white cast irons were recently included in the materials standard ISO 21988-2006 “Abrasion-resistant white cast irons”.  The microstructures of high-chromium white irons contain iron-chromium carbides distributed in a ferrous matrix which consists of one or more of the phases: austenite, pearlite and martensite.  Elemental partitioning between the carbides and the ferrous matrix influences the physical and chemical properties of high-chromium white irons which exhibit a broad range of wear resistance, corrosion resistance and fracture toughness in service. The resistance of high-chromium white iron to erosion and corrosive wear is largely determined by its composition and microstructure. This talk will address metallurgical issues of high-chromium white irons for effective applications in oilsands and chemical processing industries.

 

 

 

Application of Oxygen-Active Elements for

High-temperature Wear Control

D.Y. Li

Department Of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, Canada T6G 2G6

 

Wear at elevated temperatures generally involves oxidation that affects the wear process through influencing the metal-to-metal contact and properties of both the target surface and wear debris. The resultant effect on wear could be negative or positive, largely depending on the oxide’s properties and the oxidation mechanism. Extensive studies have demonstrated that the high-T wear resistance of engineering alloys could be improved by alloying with a small amount of rare-earth or oxygen-active elements (OAE) such as yttrium and cerium. OAE can influence the oxide growth rate, improve the scale adherence to the substrate, and change the oxidation mechanism from outward metal ions transport to inward oxygen ions transport.  This talk will discuss general features of wear at elevated temperatures and, in particular, address the benefits of OAE with fundamental understanding for high-T wear control.