Adhesive wear description

In addition to this qualitative description of wear, some progress has been made in formulating a quantitative description. For the most common form of wear, adhesive wear ... 

General Description. Adhesive wear is defined as wear by transference of material from one surface to another during relative motion under load due to a process of solid-state welding (Fig. 16) particles that are removed from one surface are either permanently or temporarily attached to the other surface. 

The adhesive transfer of organic plastics has some special features of it own. Makinson and Tabor [24] observed that polytetrafluoroethylene sliding on glass left transferred material on the counter surface in the form of lumps, ribbons, sheets or very thin films, depending on the rubbing conditions. Pooley and Tabor [25], who studied the transfer process more intensively, also reported the behavior of other polymers such as fluorocarbon copolymers, polyethylene, polypropylene, polystyrene, polymethylmethacrylate and polyvinyl chloride. Descriptions of transfer in relation to wear were reported for PTFE by Tanaka tt ai. [20] and for polyethylene by Miller a.1. [21]... 

An important aspect of the function of compounded lubricants is to increase the load that can be carried by machinery without catastrophic damage to the rubbing components. Since the typical antiwear additives affect the viscosity of the carrier oil very little, it is not a fluid film effect that is responsible for the load-carrying augmentation. Examination of the various basic wear processes leads to the choice of the adhesive mechanism as the one most likely to respond to the action of boundary or extreme-pressure additives. The type of macroscopically observed severe wear which has this mechanistic process as its primary cause is generally designated as icu i ng (c(S. Chapter 13, Sections 13.4 and 13.6), and it is in this sense, as a description rather than a definition, that the term scuffing is used in the discussion to follow. 

Wear is a complex phenomenon, involving a wide range of possible processes (11) but invariably two of the most important governing factors are the normal load and sliding distance. At a constant normal load we have observed that both the non-stationarity and microslip increase with velocity. In terms of the adhesion model of friction, which provides a quantitative description of the frictional behaviour of PET fibres (2-3) a frictional event is the formation and subsequent rupture of an adhesive junction. It is reasonable to suppose that these events are the underlying cause of wear. Micro-... 

Again, wear is the removal of material. The idea that friction causes wear and therefore, low friction means low wear, is a common mistake. Brief descriptions of five types of wear abrasive, adhesive, fatigue, chemical or corrosive, and fretting — may be found in Reference 2 as well as in other references in this article. Next, it maybe useful to consider some of the major concepts of lubrication. 

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