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Wear resistance of case-hardened electrolytic coatings
SYSTEMATIC
ABSTRACTS
OF CURRENT
LITERATURE
ments in roller bearings during the next decade are discussed in an interview report with T. W. Morrison of SKF Industries Inc. The techniques discussed include electron beam melting, ausforming, high-temperature carburizing and powder metallurgy. The advantages to be gained are given. Cast-aluminium Alloys in a Marine Environment for Twenty Years. S. C. Hailstone, MetaZburgia, 80 (450) (1969) KjG--140.
The paper presents the results of exposure tests carried out in a marine environment for a period of twenty years on a number of sand and gravity die-cast aluminum alloys in the unprotected condition and protected in various ways. Hard Metal with Added Hardness. Anon., Metallurgia, 80 (482) (1969) 239-240. Conventional tungsten carbide-based hard metals with very thin (5-15 ,um) surface coating of exceptionally higher wear-resistant materials combine the basic toughness of conventional hard metals, with a very highly wear-resistant surface, form tool tips suitable for severe machining conditions. Wear of Polyimide Resin. R. B. Lewis, ~~~~~ca~~o~Eng., 356-359;
25 (9) (1969)
5 figs., 9 refs.
Using a thrust-bearing test apparatus the unlubricated wear rate of SP-PI polyimide resin sliding against machine surfaces was found to be directly proportional to pressure and velocity over a wide range of application paiameters. The basis for predicting mild wear performance is defined. The limits of the mild wear regime are shown to be related to the polymer’s surface temperature. The relationship between surface temperature limit and PV limit is explored, The outstanding mechanical properties coupled with relatively low thermal expansion make polyimides important contenders for high-temperature bearings, seals, piston rings and gears. Mechanical Strength and Surface Microstructure of Partialiy Crystallised Glasses. P. W. McMillan, B. P. Hodgson and R. E. Booth,J. Mater. SC&, 4 (12) (1969) Iozg-1038; 4 figs., 3 tables, 3 refs. The influence on the mechanical strength of lithia-silica glasses of heat treatment in the temperature range 400-6oo’C where the degree of crystallisation is small, has been studied. Heat treatment of a binary glass led to a significant increase of mechanical strength. From observations of the effect of abrasion on mechanical strength it appeared that the stren~hening effect arose from a change in surface structure of the glass. Ex-
34
amination by electron microscopy and X-ray diffraction and the mechanical properties are discussed in relation to the surface structure of glass. Effect of Toughness on Wear Resistance of Tool Steels. F. Uranc, Materialfw’df., .rz (I) (1970) 7-13; 7 figs., 2 tables, IO refs. A study of resistance of tool steels to sliding wear under various conditions of shock loading. Calculating the Wear on Graphite Piston Rings. Yu. N. Vasil’ev and S. .4. Kolesnikov, Russian Eng. J., 49 (3) (rg6g) 20-23; z figs., z tables, 5 refs. (Transl. by P.E.R.A. of Gt. Britain of Vestn. Mashinsstr. ,4g (3) (1969) 20-22.) A method of calculating wear based on the use of friction test results has been used to calculate the wear in compressors and steam engines. Wear Resistance of Case-hardened Electrolytic Coatings. V. C. Dazhen and R. L. Engalychev, Russia% Eng. f., 49 (3) (1969) 56-58; 3 figs., 2 tables, 6 refs. (Transl. by P.E.R.A. of Gt. Britain of lrest%:. ~~~5~~~0~~~. , .+g (3) (1969) 52-55.) Tests were performed to assess the wear resistance of case-hardened electrolytically deposited metals. Case hardening greatly increases the resistance of the deposits to all types of wear and it is recommended for extensive use in the recovery of spindles, shafts, etc. 5.2. Wear phenomena Predicting the Wear on Railway Wheels. I. B. Tartakovskii, Russian Eng. J., #g (4) (rg6g) 17-20; 4figs., z tables, 5 refs. (Transl. by P.E.R.A. of Gt. Britain of v&n. Mas~~~~st~., 49 (4) 1969 I&-IQ.) Wear equations are derived from which it is possible to predict reliably the progress of wear on railway wheels over long periods by mathematical analysis of wear measurements of identical wheels after a relatively short service duration. It may be assumed that similar predictions are possible for other machine elements. Stress Variations with Wear-Solid-lubricant Films-Pin on Disc Apparatus. V. Hopkins and R. J. Schroeder. Lubrication EBg., 25 (9) (1969) 360-364; IO figs., I table, 6 refs. A sharp decrease in the projected area stress was observed during wear life tests of a solidWear, 15 (1970) 297-306
ABSTRACTS
OF CURRENT
LITERATURE
ments in roller bearings during the next decade are discussed in an interview report with T. W. Morrison of SKF Industries Inc. The techniques discussed include electron beam melting, ausforming, high-temperature carburizing and powder metallurgy. The advantages to be gained are given. Cast-aluminium Alloys in a Marine Environment for Twenty Years. S. C. Hailstone, MetaZburgia, 80 (450) (1969) KjG--140.
The paper presents the results of exposure tests carried out in a marine environment for a period of twenty years on a number of sand and gravity die-cast aluminum alloys in the unprotected condition and protected in various ways. Hard Metal with Added Hardness. Anon., Metallurgia, 80 (482) (1969) 239-240. Conventional tungsten carbide-based hard metals with very thin (5-15 ,um) surface coating of exceptionally higher wear-resistant materials combine the basic toughness of conventional hard metals, with a very highly wear-resistant surface, form tool tips suitable for severe machining conditions. Wear of Polyimide Resin. R. B. Lewis, ~~~~~ca~~o~Eng., 356-359;
25 (9) (1969)
5 figs., 9 refs.
Using a thrust-bearing test apparatus the unlubricated wear rate of SP-PI polyimide resin sliding against machine surfaces was found to be directly proportional to pressure and velocity over a wide range of application paiameters. The basis for predicting mild wear performance is defined. The limits of the mild wear regime are shown to be related to the polymer’s surface temperature. The relationship between surface temperature limit and PV limit is explored, The outstanding mechanical properties coupled with relatively low thermal expansion make polyimides important contenders for high-temperature bearings, seals, piston rings and gears. Mechanical Strength and Surface Microstructure of Partialiy Crystallised Glasses. P. W. McMillan, B. P. Hodgson and R. E. Booth,J. Mater. SC&, 4 (12) (1969) Iozg-1038; 4 figs., 3 tables, 3 refs. The influence on the mechanical strength of lithia-silica glasses of heat treatment in the temperature range 400-6oo’C where the degree of crystallisation is small, has been studied. Heat treatment of a binary glass led to a significant increase of mechanical strength. From observations of the effect of abrasion on mechanical strength it appeared that the stren~hening effect arose from a change in surface structure of the glass. Ex-
34
amination by electron microscopy and X-ray diffraction and the mechanical properties are discussed in relation to the surface structure of glass. Effect of Toughness on Wear Resistance of Tool Steels. F. Uranc, Materialfw’df., .rz (I) (1970) 7-13; 7 figs., 2 tables, IO refs. A study of resistance of tool steels to sliding wear under various conditions of shock loading. Calculating the Wear on Graphite Piston Rings. Yu. N. Vasil’ev and S. .4. Kolesnikov, Russian Eng. J., 49 (3) (rg6g) 20-23; z figs., z tables, 5 refs. (Transl. by P.E.R.A. of Gt. Britain of Vestn. Mashinsstr. ,4g (3) (1969) 20-22.) A method of calculating wear based on the use of friction test results has been used to calculate the wear in compressors and steam engines. Wear Resistance of Case-hardened Electrolytic Coatings. V. C. Dazhen and R. L. Engalychev, Russia% Eng. f., 49 (3) (1969) 56-58; 3 figs., 2 tables, 6 refs. (Transl. by P.E.R.A. of Gt. Britain of lrest%:. ~~~5~~~0~~~. , .+g (3) (1969) 52-55.) Tests were performed to assess the wear resistance of case-hardened electrolytically deposited metals. Case hardening greatly increases the resistance of the deposits to all types of wear and it is recommended for extensive use in the recovery of spindles, shafts, etc. 5.2. Wear phenomena Predicting the Wear on Railway Wheels. I. B. Tartakovskii, Russian Eng. J., #g (4) (rg6g) 17-20; 4figs., z tables, 5 refs. (Transl. by P.E.R.A. of Gt. Britain of v&n. Mas~~~~st~., 49 (4) 1969 I&-IQ.) Wear equations are derived from which it is possible to predict reliably the progress of wear on railway wheels over long periods by mathematical analysis of wear measurements of identical wheels after a relatively short service duration. It may be assumed that similar predictions are possible for other machine elements. Stress Variations with Wear-Solid-lubricant Films-Pin on Disc Apparatus. V. Hopkins and R. J. Schroeder. Lubrication EBg., 25 (9) (1969) 360-364; IO figs., I table, 6 refs. A sharp decrease in the projected area stress was observed during wear life tests of a solidWear, 15 (1970) 297-306