Tribology in Manufacturing Technology

This chapter introduces the concept of the cutting tool tribology of a part of the metal cutting tribology. It argues that the importance of the subject became actual only recently because the modern level of the components of the machining system can fully support improvements in the cutting tool tribology. The underlying principle for tribological consideration is pointed out. The major parameters of the tribological interfaces, namely the tool-chip and tool-workpiece interfaces are considered. The chapter also describes an emerging mechanism of tool wear known as cobalt leaching. The rest of the chapter presents some improvements of tribological conditions of cutting tools as the use of application specific grades of tool materials, advanced coating and high-pressure metal working fluid (MWF) supply.

The chapter focuses on the tribological interactions in the area of machining and grinding and details the frictional interactions at the chip-tool interface. The chapter then discusses cutting, ploughing and sliding interaction models that are generally applied to the actions of cutting tools and provides solutions to reducing these interactions using solid and liquid lubricants. The authors intend to provide an understanding to readers of the chapter to design better processes for machining difficult-to-machine materials used in industry at large.

This chapter presents the main aspects of the tribological systems observed in the most important metal forming processes. Friction, wear and lubrication are discussed in general terms to describe friction models, wear mechanisms and lubrication regimes commonly found in metal forming, which are analyzed for each of the five groups of processes (rolling, extrusion, forging, drawing and stamping). Recent developments concerning to environmental and cost reduction are also discussed.

Contact friction is of crucial importance for accurate simulation, optimum design and control of industrial rolling processes. It affects the shape, profile, dimensional accuracy and surface quality of hot rolled strips. This chapter focuses on the tribology of hot strip rolling of plain carbon steel and stainless steel, which is significantly affected by oxide scales. The fundamental of oxidation of pure iron, plain carbon steel and stainless steel, and the formation of oxide scales in hot rolling process have been discussed. The morphology of the oxide scales and their deformation behaviours that depend on oxide scale thickness, constitution and the rolling parameters have been disclosed. Surface roughness of oxide scales and the tribological effect of oxide scales in hot strip rolling have been studied. A multi oxide scale layers simulation has been established to study the deformation and fracture of oxide scales taking into account the effect of surface roughness.

Metalforming tribology is a science and technology of a huge system. At the midst of this system is situated the micro-contact mechanism. The micro-contact mechanism in the presence of lubricant have generally been classified into the regimes of boundary, mixed and hydrodynamic lubrication depending on the average lubricant film thickness and the surface roughnesses of tool and workpiece. In these mechanism, there proceeds mechanical interaction between the surface microstructures of workpiece and tool and the lubricant. First, this paper presents the micro-contact at the interface between tool and workpiece under each lubrication regime. Second, the micro-contact at the interface between tool and workpiece in sheet metals forming, and sheet rolling are explained.

This chapter presents the development of new coatings in order to minimize the effects of wear on the tools of manufacturing processes. The coating materials with hard layers results in increased wear resistance and decreasing the coefficient of friction, allowing a better tribological performance of tools and a reduction in machine downtime due to premature failure. The Plasma nitriding, the Chemical Vapor Deposition (CVD), the Physical Vapor Deposition (PVD), the Physical–Chemical Vapor Deposition (PCVD), some thermochemical treatments, multilayer coatings and Diamond-Like Carbon (DLC) were discussed. The physical vapor deposition can be obtained through three technical features: deposition by vacuum evaporation, cathode sputtering and ion plating. Some coatings properties, such as high hardness, low friction coefficient and high chemical and thermal stability, are primarily responsible for the diversity of applications of these coatings. In this chapter are also presented and compared the properties of various surface coatings applied in the industry.