Abrasive wear definition

Definition Thermoplastic fiber with exc. heat and chem. resist. easily melt processable exc. dimensional stability, creep resist., fatigue resist., abrasion/wear resist. high dielec. str. 

Table 26.7 gives a list of the boundary conditions which define a tire wear test simulation and in fact also an acmal road test. The road surface is the laboratory surface on which the abrasion data for the simulation were obtained. There is as yet no definition of a road surface and even if there were one, it would be of httle use since road surface structures change frequently along the road surface as pointed out earlier. 

From these definitions, it can be seen that the more specific meaning of abrasion is wear by the cutting action of hard asperities. The common practice in the rubber industry of using abrasion as a general term for wear probably results from the fact that most wear tests for rubbers use the action of sharp asperities, for example abrasive paper, to produce wear. 

The term tooth wear is commonly used to describe the loss of tooth hard tissue due to non-carious causes [1], This encompasses a variety of both chemical and mechanical causes of both intrinsic and extrinsic origin. The term tooth wear is preferred over some of the more precise definitions of individual hard tissue loss mechanisms, because it acknowledges the fact that wear is usually a multifactorial process one mechanism may dominate, but the overall wear is commonly due to the interaction between two or more wear mechanisms. In dentistry, the terms erosion, abrasion, attrition and abfraction are widely used to describe particular mechanisms of hard tissue loss. 

The mechanisms of tooth wear fall into two distinct types those of chemical origin (e.g. erosion) and those of physical origin (e.g. abrasion, attrition). In any individual, both chemical and physical insults to the tooth hard tissue will be present in some form or other, so tooth wear is the combined effect of these insults. Despite the clear definition of a number of distinct tooth wear mechanisms, it is uncommon to find a single wear mechanism present in the... 

The general definition of wear is the loss of material by any means, but it is usually taken to be loss caused by rubbing together of two surfaces, and the word is used in that sense here. Abrasion is then essentially another word for wear, and the two are commonly used indiscriminately. One aspect of the wear process is fatigue on a micro scale. 

Pintle chain, characterized by a pin which connects the links, is used for more rigorous service such as vertical grain elevators. Steel chain is used where high strength or good wearing qualities, or both, are needed. Roller chain is fitted with rollers or wheels to minimize friction and reduce wear. Combination chain is made in such a way that different features of the above three types are combined to provide certain definite performance characteristics. Chains of special alloys are available for operation in the presence of extreme or adverse factors such as heat, chemicals, abrasive substances, and so on. Some chain-link types are shown in Figure 3.25. 

Significant research and developmental efforts have been placed to characterize and improve abrasion and wear resistance of polymers (2-5). However, advances in fundamental knowledge on abrasion and wear are limited mainly because of the complexity of the available test methods, such as the Taber abrasion test. No direct correlation between the applied loading conditions and the observed abrasion damage can be made. As a result, no definitive relationship between material parameters and abrasion resistance can be established. 

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