Advanced Engineering Design

Tribological behaviour of carbide-free bainitic steel under dry rolling/sliding conditions

Abstract: The dry rolling/sliding wear behaviour of Si alloyed carbide free bainitic steel austempered at different temperatures and sliding distances has been evaluated. 60SiCr7 spring steel samples were au ...

Tribology of selective laser melting processed parts: Stainless steel 316 L under lubricated conditions

Abstract: Selective laser melting is an additive manufacturing technology that produces metal parts; 316 L stainless steel is one of the most widely used material in the selective laser melting process. The tribology performance of selective laser melting processed parts is critically important for industrial applications but related studies are rare. In this study, friction and wear behaviors of 316 L stainless steel processed both by selective laser melting and traditional methods have been investigated using a ring-on-disc rig under lubricated conditions. The selective laser melting processed sample had molten pools, pores and fine grains in the microstructure, unlike the traditionally processed sample. The selective laser melting processed sample had slightly lower friction and wear than the traditionally processed sample when in contact with brass. When the selective laser melting and traditionally processed samples came in contact with a hard material, the differences in friction and wear were noticeable. The wear mechanism of the selective laser melting processed sample under the given contact condition has been proposed. Pores and refined grains in the selective laser melting processed 316 L stainless steel affected the friction and wear differently; consequently, both factors needs to be considered together.

Use of the Manufacturing System Design Decomposition for Comparative Analysis and Effective Design of Production Systems

Abstract: The focus of this paper is on the use of the Manufacturing System Design Decomposition (MSDD) to make effective cost and production system design decisions. A comparative study is conducted to illustrate how and why the total cost is reduced when the functional requirements defined by the MSDD are achieved. The ultimate goal of this research was to advance manufacturing and production system development to being guided by engineering science and design rather than the common practice of duplicating another person’s or entity’s notion of the best physical implementation.

An Engineering Systems Introduction to Axiomatic Design

Abstract: Since its first publication in 1978, Axiomatic Design has developed to become one of the more commonly applied engineering design theories in the academic literature and industrial practice. In parallel, model-based systems engineering (MBSE) has developed from industrial origins in the aerospace, communications, and defense sectors. As the scope of humanity’s engineering efforts grows to include evermore complex engineering systems, the engineering design methodologies that guide these efforts must also develop. These two, now well-established but independently developed, engineering design methodologies now appear well poised to support the synthesis, analysis, and resynthesis of large complex engineering systems. As the first chapter in this book on the application of Axiomatic Design to large complex systems, it introduces the fundamentals of Axiomatic Design within the context of engineering systems and as a conceptual foundation for subsequent chapters. It also relates Axiomatic Design’s key concepts and terminology to those found in current MBSE techniques including SysML. The chapter concludes with applications in which Axiomatic Design has served to advance the development of engineering systems including quantitative measures of life cycle properties, design of cyber-physical systems, and design of hetero-functional networks.

A study on the influence of surface topography on the low-speed tribological performance of port plates in axial piston pumps

Abstract: Axial piston pumps are widely used under severe conditions because they are able to operate highly efficiently at high pressure and various ranges of speed. However, pump efficiency is relatively low at low speed because of insufficient lubrication. The contact between the port plate and cylinder barrel is critically important because insufficient lubrication from this pair causes rapid wear and high friction loss which significantly reduces pump efficiency. Ring-on-disc testing was conducted to investigate the friction and wear behaviours of the port plate–cylinder barrel contact. Four types of surface finishing processes were used: coarse grinding, fine grinding, polishing, and laser texturing. A confocal laser scanning microscope and energy dispersive spectroscopy were used to examine the surface. Results indicate that the polished surfaces have the best tribological performance. Finely ground surfaces have lower wear but higher friction than coarsely ground surfaces. The number and size of the brass particles transferred to the steel surface are related to the surface topography. Laser textured surfaces have the highest friction and wear. Brass particles aggregate inside micro-dimples. Increasing contact pressure does not change the wear mechanism but increases abrasion.