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Tribology in Czechoslovakia
In Professor Kragelskii's laboratory much effort has been placed on the study of selective transfer mechanisms during the wear process as well as of hydrogen-embrittlement. An extensive study has been made of friction in vacuum using apparatus in which a mass spectrometer was combined with the actual friction apparatus. Most of the results of this study are included in Professor Kragelskii's recent book "Friction and Wear in Vacuum".
heating. If was now possible to simulate in the laboratory situations which would be very expensive to study on a full scale. Work was proceeding on elastohydro-dynamic lubrication and Professor Petrusovic considered that it w a s necessary to employ variable piezo coefficients in order to obtain rational theoretical results using the finite element technique.
A most impressive investigation dealt with the study of thin layers by a continuous X-ray observation. A: special X-ray camera projected the incident X-rays along a line which was nearly parallel to the surface. This ray passed through two slits and fell on the sample with a definite angle. Changes in this angle allowed the depth of various features to be investigated by changes in the X-ray lattice parameters. The nature of the lubricant was shown to affect the density and location of dislocations. Professor Kragelskii attached great importance to fatigue processes in the generation of wear debris and has produced an analytical method for estimating the wear rate. He uses the well-known SN curve and the same concepts of dislocations which are used to explain the conventional failure.
Adhesion between wheel and rail
The method of measuring wear using a diamond incision as a witness which has been described in the literature is now available commercially in forms suitable for the study of the wear of both planes and cylinders. The section engaged on braking studies had as its objective the production of a theoretical model for general application to the friction problems of materials. Simulating friction and wear involves calculating the degree of frictional
The factors governing the adhesion between wheel and rail, as well as being of great tribological interest, are one of the factors determining the efficiency of railway operation. The Academy of Sciences of the USSR Institute of Physical Chemistry had been active in this field for a number of years as evidenced by Dr. Lujnov's contribution to the proceedings of the Convention on Adhesion held by the Institute of Mechanical Engineers in London in 1963. Dr. Lujnov has maintained his interest in the subject. He emphasises the great importance of relative humidity in association with surface-active substances acting on particulate material on the surface of the raft. As regards the application of the results to practice, he has provided a set of statistically based tables whereby the rules to be applied at different times in different geographical locations to govern train loading were determined from a point of view of maintaining time-keeping, taking into account probable variations in adhesion. F. 7". Barwell Department of Mechanical Engineering, University College of Swansea, Swansea, SA2 8PP, UK
Tribology in Czechoslovakia The Czechoslovak Socialist Republic, a country with a high: ly developed industry, devotes great attention to increasing the service life of machinery manufactured in all branches of industry and particularly to the connected questions of friction, wear and lubricants (tribology). Scientific work on tribology is being stepped up in national research institutes, in institutes controlled by the relevant ministries and production concerns, and in technical universities. The field of journal bearings and seals is covered by the National Research Institute for Machinery, Praha; research into ball bearings is the concern of the Research Institute Concern of the Production of Ball Bearings, Bmo. Research into wear and wear-resistant materials is carried out by: National Research Institute for Materials, Praha; Research Institute SIGMA-Olomouc; Research Institute Vitkovice Iron and Steel & Engineering Works Klement Gottwald, Ostrava; Research Institute for Powder Metallurgy Sumperk; Welding Research Institute in Bratislava; CKD - Praha: SKODA - Plzen, etc. The complex of problems connected with lubricants and lubrication is the scope of Chemopetrol, Praha, and the Research Institute for Crude Oil and ttydrocarbon Fuels in Bratislava. Tribology is also studied at the technical universities in Praha, Brno, Bratislava, Nitra; Liberec and Ostrava.
There is a specialized tribology group, which has been working on this subject for over 12 years: another specialized group has been working on techniques of lubrication for over 20 years, and still another group is concerned with fuels and lubricants. A large-scale lecture activity on tribology is being organized by all specialized groups, together with further meetings for interested technical staff. International meetings have also been organized in Czechoslovakia, including conferences on crude oil, cavitation etc. The progress in tribological knowledge in Czechoslovakia is strongly influenced by the requirements of the national economy and of industry. The maximum service life of machines, with minimum operational and material cost, c a n be achieved only by the application of the tribological knowledge in designing, producing, and using machinery. Developments in high-grade lubricants, wear-resistant materials, bearings, seals, and methods of testing and diagnosis are necessary. Application of tribological knowledge enables the industry to achieve important economic results. For this reason considerable attention and help is given to research in this area by manufacturing works and central institutions. M. Vocel
Cooperation between scientific and industrial workers and the staff of technical universities takes place, at present, within the framework of the Scientific Technical Society.
National Research Institute of Materials, Praha 1, Opletalova 25, CSSR
TRIBOLOGY international February 1978 41
heating. If was now possible to simulate in the laboratory situations which would be very expensive to study on a full scale. Work was proceeding on elastohydro-dynamic lubrication and Professor Petrusovic considered that it w a s necessary to employ variable piezo coefficients in order to obtain rational theoretical results using the finite element technique.
A most impressive investigation dealt with the study of thin layers by a continuous X-ray observation. A: special X-ray camera projected the incident X-rays along a line which was nearly parallel to the surface. This ray passed through two slits and fell on the sample with a definite angle. Changes in this angle allowed the depth of various features to be investigated by changes in the X-ray lattice parameters. The nature of the lubricant was shown to affect the density and location of dislocations. Professor Kragelskii attached great importance to fatigue processes in the generation of wear debris and has produced an analytical method for estimating the wear rate. He uses the well-known SN curve and the same concepts of dislocations which are used to explain the conventional failure.
Adhesion between wheel and rail
The method of measuring wear using a diamond incision as a witness which has been described in the literature is now available commercially in forms suitable for the study of the wear of both planes and cylinders. The section engaged on braking studies had as its objective the production of a theoretical model for general application to the friction problems of materials. Simulating friction and wear involves calculating the degree of frictional
The factors governing the adhesion between wheel and rail, as well as being of great tribological interest, are one of the factors determining the efficiency of railway operation. The Academy of Sciences of the USSR Institute of Physical Chemistry had been active in this field for a number of years as evidenced by Dr. Lujnov's contribution to the proceedings of the Convention on Adhesion held by the Institute of Mechanical Engineers in London in 1963. Dr. Lujnov has maintained his interest in the subject. He emphasises the great importance of relative humidity in association with surface-active substances acting on particulate material on the surface of the raft. As regards the application of the results to practice, he has provided a set of statistically based tables whereby the rules to be applied at different times in different geographical locations to govern train loading were determined from a point of view of maintaining time-keeping, taking into account probable variations in adhesion. F. 7". Barwell Department of Mechanical Engineering, University College of Swansea, Swansea, SA2 8PP, UK
Tribology in Czechoslovakia The Czechoslovak Socialist Republic, a country with a high: ly developed industry, devotes great attention to increasing the service life of machinery manufactured in all branches of industry and particularly to the connected questions of friction, wear and lubricants (tribology). Scientific work on tribology is being stepped up in national research institutes, in institutes controlled by the relevant ministries and production concerns, and in technical universities. The field of journal bearings and seals is covered by the National Research Institute for Machinery, Praha; research into ball bearings is the concern of the Research Institute Concern of the Production of Ball Bearings, Bmo. Research into wear and wear-resistant materials is carried out by: National Research Institute for Materials, Praha; Research Institute SIGMA-Olomouc; Research Institute Vitkovice Iron and Steel & Engineering Works Klement Gottwald, Ostrava; Research Institute for Powder Metallurgy Sumperk; Welding Research Institute in Bratislava; CKD - Praha: SKODA - Plzen, etc. The complex of problems connected with lubricants and lubrication is the scope of Chemopetrol, Praha, and the Research Institute for Crude Oil and ttydrocarbon Fuels in Bratislava. Tribology is also studied at the technical universities in Praha, Brno, Bratislava, Nitra; Liberec and Ostrava.
There is a specialized tribology group, which has been working on this subject for over 12 years: another specialized group has been working on techniques of lubrication for over 20 years, and still another group is concerned with fuels and lubricants. A large-scale lecture activity on tribology is being organized by all specialized groups, together with further meetings for interested technical staff. International meetings have also been organized in Czechoslovakia, including conferences on crude oil, cavitation etc. The progress in tribological knowledge in Czechoslovakia is strongly influenced by the requirements of the national economy and of industry. The maximum service life of machines, with minimum operational and material cost, c a n be achieved only by the application of the tribological knowledge in designing, producing, and using machinery. Developments in high-grade lubricants, wear-resistant materials, bearings, seals, and methods of testing and diagnosis are necessary. Application of tribological knowledge enables the industry to achieve important economic results. For this reason considerable attention and help is given to research in this area by manufacturing works and central institutions. M. Vocel
Cooperation between scientific and industrial workers and the staff of technical universities takes place, at present, within the framework of the Scientific Technical Society.
National Research Institute of Materials, Praha 1, Opletalova 25, CSSR
TRIBOLOGY international February 1978 41