Mechanics of Wear

FIG U RE 10.35 Sketch of a single surface ridge subjected to a frictional (tearing) force F. (From Southern and Thomas (1978).) 

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The material removal in CMP is attributed to multi mechanisms of wear, including abrasive, adhesive, erosive, and corrosive wear. 

Abrasion involves a combination of processes including mechanical, mechano-chemical, and thermochemical. Several mechanisms of wear and abrasion have been reported. The abrasion of... 

Abrasion of rubber by loose abradant is clearly a different situation to that where solid abradants are involved. The mechanisms of wear under those conditions have been investigated for several materials77 78. 

Orthopaedic prosthesis Mechanism of wear of Ultra-high molecular weight polyethylene currently used in total hip and knee joint implants— see J. Mater. Set. 28 1045-1058 (1993). 

The wear of rubber is a technologically important phenomenon unfortunately, it is also an extremely complex one. A detailed discussion of the mechanisms of wear is beyond the scope of this review. The role of carbon black in abrasion and wear, however, is most relevant in the present context in view of the practically universal use of this pigment in automobile tire treads. 

Preventive maintenance is applied when the expected useful life of an item can be confidently estimated or when prediction models for the mechanism of wear of an item are available. The fact that preventive maintenance is a costintensive activity dictates that it is applied to items whose failure is critical to the system or could pose dangers to the operators. In order to identify the right type of maintenance. 

Adhesive Wear Characterized by the transfer of material from one surface to another surface during relative motion. This type of wear is a consequence of adhesive forces acting at the junction of surface asperities. The transferred fragments may either be permanently or only temporarily attached to the other surface. Adhesive wear has been denoted as being the most commonly detected mechanism of wear, unfortunately it is also the least preventable (Dowson, 1981). 

Wear is defined as the damage to a solid surface, generally involving progressive loss of material, due to relative motion between that surface and a contacting substance or substances. The mechanisms of wear are abrasion, adhesion, erosion, fatigue and fretting. 

Figure 3.353 Mechanisms of wear a) inside limit layer b) outside limit layer [954],...

The source produces the wear particles and the mechanisms of wear particle production ... 

The question now arises which fracture processes, if any, are strongly affected by the local chemical structure Two examples are considered below tearing and crack growth, and abrasive wear. Under certain conditions these failure processes are found to depend upon particular features of the elastomer molecule and they are therefore distinctly different, even for closely-related chemical structures. Natural rubber can usefully be compared with cis 1, 4-polybutadiene in this respect, because, although their chemical structures are superficially similar, large differences are observed in their resistance to tearing and in the mechanism of wear. 

The development of suitable compounds by optimising critical properties, manufacturing, field testing, failure analysis and mechanism of wear of tank track pads for a battle tank are described. Four compounds based on NR, SBR, NR/SBR and hydrogenated nitrile rubber were developed with optimum physical properties. 19 refs. INDIA... 

The mechanisms of wear in industrial cells are a combination of physical and chemical wear in spite of the fact that the physical wear is much smaller. 

A wear study by McKellop et al. indicated that Poly n exhibited a 10 times greater wear rate than UHMWPE against a variety of common counterfaces, such as 316 stainless steel and CoCr alloy [19]. Because the major mechanism of wear in carbon fiber-reinforced polyethylene is abrasive wear that induces the drawing out of fibers from bearing surfaces [20], the interface strength is of critical importance in the overall performance of Poly II and similar composites. 

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