Determination of Resistance to Abrasive Wear. XI. Influence of the Type of Abrasive

Abstract Tests with the du Pont machine show that the practice of expressing abrasion test results as an abrasive index, i.e., abrasion-resistance relative to a standard rubber, does not enable different types of abrasive to be used indiscriminately because these are found to give widely different abrasive indices for the same rubber; thus, some abrasives may give four times as high an index as others. If attention is confined to abrasive papers, as distinct from bonded abrasive wheels, this variation is reduced, but is still large enough to be a serious factor in accurate work. It is clear that, even when this comparative method of testing is used, standardization of the abrasive paper is essential to reduce discrepancies between results obtained in different laboratories. Discrepancies will still exist, however, because abrasive paper is not uniform, and there is evidence that abrasive indices determined on different portions of the same paper may differ as much as those from different types of paper. To minimize the effect of this nonuniformity, two courses are open. (1) All the rubbers to be compared could be abraded on one and the same area of paper, preferably a large area to avoid wearing the surface, e.g., by giving each rubber a short run on each of the several paper discs used, instead of using a different disc for each rubber. (2) Different specimens could be tested on the two sides of the machine provided this has a pivotted arm. It is shown that this technique has several advantages. The factors that cause the abrasive index to vary from one abrasive to another are not known; it appears, however, that the degree of abrasiveness is not a determining factor. The two methods of calculating abrasion loss—as cc. per hr. and cc. per H.P.-hr.,—usually do not give the same abrasive index; in any standard test method it is therefore essential to state which is to be used. The variation of the abrasive index from one abrasive to another is the same whichever method of calculation is used.

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Determination of Steady-State Adhesive Wear Rate

World Tribology Congress III, Volume 1 ◽

10.1115/wtc2005-63900 ◽

2005 ◽

Cited By ~ 1

Author(s):

L. J. Yang

Keyword(s):

Steady State ◽

Wear Rate ◽

Wear Test ◽

Standard Test ◽

Test Method ◽

Testing Time ◽

Wear Coefficient ◽

Wear Rates ◽

Test Methodology

Wear rates obtained from different investigators could vary significantly due to lack of a standard test method. A test methodology is therefore proposed in this paper to enable the steady-state wear rate to be determined more accurately, consistently, and efficiently. The wear test will be divided into four stages: (i) to conduct the transient wear test; (ii) to predict the steady-state wear coefficient with the required sliding distance based on the transient wear data by using Yang’s second wear coefficient equation; (iii) to conduct confirmation runs to obtain the measured steady-state wear coefficient value; and (iv) to convert the steady-state wear coefficient value into a steady-state wear rate. The proposed methodology is supported by wear data obtained previously on aluminium based matrix composite materials. It is capable of giving more accurate steady-state wear coefficient and wear rate values, as well as saving a lot of testing time and labour, by reducing the number of trial runs required to achieve the steady-state wear condition.

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