482 Wear - Elsevier Sequoia S.A., Lausanne - Printed in the Netherlands

Reproducible friction and wear testing machines which can predict lubricant per- formances

HARRY M. SCHIEFER

Dow Corning Corporation, Munich (Germrl~r 1’)

Measurement of the complex phenomena of friction and wear requires laboratory test machines which can be controlled to give reproducible results and versatile enough to be able to simulate actual service conditions. Prediction oflubricant field performance by laboratory testers is a valuable asset to save money and time for new product development and to solve field problems. Two laboratory testers, which were developed in the Dow Corning Laboratories and designated as the LFW-1 and LFW-4l, are described from the reproducibility and correlation standpoint2-5. It is shown that the LFW-1 is a versatile machine which can predict field performance when variables are controlled such that they duplicate service conditions as closely as possible.

The application of results from service simulation tests is illustrated by reference to piston ring wear tests 3,6, the development of fluorosilicone lubricant@,‘, the development of lubricants suitable for the lubrication of titanium under oscillating conditions8-10 and for the solution of space lubrication problems”*“.

It is also demonstrated that the LFW-4 machine duplicates a specific function of press fitting and further predicts other slow speed applications’2S’3. The results from such tests have been of considerable practical use as illustrated by reference to the moving of very large, heavy structures such as bridges14- 18.

REFERENCES

1

2

3 4

5

6

7

8

9

10

11 12

H. T. AZ-LAM, Friction and wear testing machines to evaluate tomorrow’s lubricants, 23rd ASLE Meeting, Cleveland, May 6-9, 1968, Preprint 68 AM IB-4. Calibration and operation of the alpha model LFW-1 Friction and Wear Testing Machine, ASTM Design. D 2714-68. Accelerated Wear Tests of Piston Rings, Automot. Znd., May 15, 1969. J. R. JONES, Low-load oscillating tests of bonded solid lubricants and composites, 23rd AXE Meeting, Cleveland, Muy 6-9, 1968, Preprint 68 AM 4C-2.

A. DI SAPIO AND F. LINDSEY, Some effects of oscillatory motion on bonded, solid film lubricants, 25th ASLE Meeting, Chicago, May 4-8, 1970. H. M. SCHIEFER, H. T. AZZAM AND J. W. MILLER, Industrial fluorosilicone applications predicted by

laboratory tests, Lubrication Eng., 25 (5) (1969) 210-220. R. E. SMITH, E. D. GROENHOF AND W. 0. WINER, The behaviour of fluorosilicones as lubricants, Synthetic Lubricants Symposium, A.Z.Ch.E., Atlanta, Georgia, Feb. 18, 1970. S. J. KOSTMAN, Lubricants and wear coatings for titanium, ASTM Symposium on Applications Related Phenomena in Titanium Alloys, Los Angeles, Caky, April 1967. F. G. A. DE LAAT AND T. ADAMS, Inhibiting the wear and galling characteristics of titanium, ASM Meeting, Los Angeles, California, March 11-14, 1968. F. G. A. DE LAAT, R. V. SHELTON AND J. H. KINSEY, Status of lubricants for manned spacecraft,

Lubrication Eng., 23 (4) (1967) 145-153. F. G. A. DE LAAT, Testing dry film lubricants for space use, Res./Deuelop., August (1968) 52-55. J. GANSHEIMER, Testing method for the determination of the static and dynamic coefficients of friction of lubricants at high loadings (Press fit-test), MaterialpriiJ, 8 (7) (1966) 256259.

Wear, 17 (1971) 482-483

AUTHORS’ ABSTRACTS 483

13 E. BODARD AND L. LELOUP, Experimentaluntersuchen iiber die Erscheinung des Stick-Slip an Bett- bahnen von DrehbCnken, University of Liittich, 1967; also Molykote Mitt., 14 (1968) 7.

14 Molykote Mitt., 3 (1958) 2-7. 15 Molykote Mitt., 2 (1960) 4-5. 16 Molykote Mitt., 4 (1961) 6.

17 Molykote Mitt., 2 (1962) 5.

18 Molykote Mitt., 2 (1963) 2.

Wear, 17 (1971) 482483

The effect of chromium content on the sliding wear of steels as revealed by a typical pin and disc wear test rig

H. MULLER

Swedish Institute for Surface Chemistry, Stockholm (Sweden)

AND T. F. J. QUINN

University of Aston in Birmingham, Birmingham (Gt. Britain)

The philosophy of using a pin and disc apparatus to monitor possible material failure under service conditions is briefly discussed. Experiments are described in which wear rates were measured for steel pins sliding against steel discs at a speed of 100 cm s- ’ under loads of 5 kgf and 14 kgf. The steel specimens all contained 0.3 % carbon, but different amounts of chromium, namely 2 %, 8 ‘A and 12 y0 chromium. The equilibrium wear debris from each of these 6 experiments was analysed using and X-ray diffractometer technique.

It is shown that, as the chromium content is increased, there is an increase in the equilibrium wear rate, an increase in the proportion of Wtistite and a decrease in the proportion of spine1 oxide in the wear debris, for the experiments at 5 kgf load. With the 14 kgf load, there is a tendency for the wear rate to decrease with increasing chromium content. However, the relative amounts of spine1 oxide, rhombo- hedral ozide Wiistite and a-iron in the wear debris seem to be almost unaffected by changes in the chromium content of the steel specimens. In fact, the main effect of increasing the load to 14 kgf is to increase the proportion of Wiistite in the debris at the expense of the spine1 oxide. The results are discussed in terms of the oxidational behaviour of the steels.

Wear, 17 (1971) 483