Showing papers on "Tribology published in 1980"

Tribological and Mechanical Properties

Abstract: Publisher Summary This chapter explores the interactions between ion beams and metal surfaces that can lead to changes in mechanical properties Tribology is a study of friction, lubrication, and wear of engineering surfaces with a view to understanding surface interactions in detail and prescribing improvements in given applications Therefore, tribology as a subject is interdisciplinary, covering physics, chemistry, materials science, and mechanics The chapter discusses the adhesive interaction of clean surfaces and explains how this may be affected by ion implantation This is of direct relevance to the important technological areas of metal forming and extrusion in which local adhesive and plastic deformation forces are high Ion implantation is providing significant improvements in die wear behavior and may emerge as the most important advance in die treatment since the introduction of cemented tungsten carbide The applications for ion implantation in production engineering are also reviewed in the chapter The chapter discusses two types of wear test that are best suited to measurements of adhesive wear These are the pin-and-disk test and the crossed-cylinder test The object is to measure the total amount of wear removed over a given period of time as a function of load and speed

Friction and wear performance of gold and gold alloy films

Abstract: The tribological properties of gold and gold alloy coatings are of interest from two main points of view. In the electronics industry they influence the service lifetimes of electrical connectors and sliding contacts. In the aerospace industry they dictate the use of gold on moving metal parts as a solid film lubricant. Current knowledge of these properties is reviewed here with particular emphasis on this latter type of applications.

Men of tribology

Abstract: Sir William Bate Hardy was the first person to use the term \"boundary lubrication.\" He applied the techniques of physical chemistry to expose the existence and nature of the phenomenon with great skill and success equal to that achieved by Osborne Reynolds in his mathematical-physical approach to fluid-film lubrication. Yet Hardy was a biologist, and the path which led him to a study of friction and lubrication is most interesting. Hardy, the only child of William of Llangollen, North Wales, and Sarah, eldest daughter of William Bate, was born on April 6th 1864 at Erdington, Warwickshire. He was educated at Framlingham College and at Gonville and Caius College, Cambridge, which he entered in 1884. He was elected scholar in 1885 and in 1888 he obtained a First Class in Part II of the Natural Sciences Tripos, his subject being zoology. He was elected to a Shuttleworth Research Scholarship after graduation, he became a Fellow of his College in 1892 and a Tutor from 1900-1918. In 1900 he was Thurston Prizeman and in the University he was appointed Demonstrator and then, in 1913, Lecturer in Physiology. Successive generations of medical students benefited from his teaching. In an address forming part of the Centennial Celebration held in Cambridge on June 16th and 17th 1964, Professor A. V. Hill recorded his earliest recollection of Hardy. . . . \"He always seems to be dashing from one job to another; turning up at a lecture with a great bundle of papers he could not really use, at a practical class with no very clear idea of how the apparatus worked and leaving us to find out; but always unperturbed and overflowing with endearing human qualities.\

Surface temperatures and glassy state investigations in tribology, part 3. [limiting shear stress rheological model]

Abstract: Measurements were made of the limiting shear stress for two naphthenic oils of differing molecular weight and three blends of the lower molecular weight oil and polyalkylmethacrylate polymers of differing molecular weight. The two base oils reached the same limiting shear stress for the same temperature and pressure. This was also true for all the polymer solutions although the polymer reduced the limiting shear stress by about 15 percent. It is shown that limiting stress is more a function of material type than viscosity or molecular weight. A new falling body viscometer was constructed to operate to 230 C and 0.6 GPa. Another viscometer was constructed to extend the pressure range to 1.1 GPa. A concentrated contact simulator was developed which allows recording of the traction force while the slide-roll ratio is continuously varied and the rolling speed is maintained essentially constant by a single drive motor. The configuration is that of a crowned roller against a disk. Measurement of lubricant minimum film thickness of elliptical EHD contacts of various aspect ratios were made by optical interferometry. The data collected were used to evaluate the Hamrock and Dowson minimum film thickness model over a range of contract ellipticity ratio where the major axis of the contact ellipse was aligned both parallel and perpendicular to the direction of motion. A statistical analysis of the measured film thickness data showed that on the average the experimental data were 30 percent greater than the film thickness predicted by the model. Preliminary development of the application of a scanning infrared radiation system to a tribo-system was completed.

Fundamentals of tribology : proceedings of the International Conference on the Fundamentals of Tribology, held at the Massachusetts Institute of Technology, Cambridge, Massachusetts, June 1978

Abstract: Tribology, the study of friction, wear, and lubrication, is currently in a state of flux characterized by numerous challenges and counter-challenges to the facts and theories that have been proposed. With each passing year, however, the subject grows in importance: energy consumption that must be minimized, and the durability of machines extended as far as possible. This volume provides an overview of tribology and a forum for diverse views on this crucial subject. The contributors, representing both industry and academia, are all leading authorities in the field. Their comments and observations will be of great interest to researchers in mechanical engineering, materials science, energy technology, and industry.Contents: Preface and Introduction; Surface Topography; Physical Properties; Chemical Properties; Surface and Interfacial phenomena; Friction; Wear Mechanisms; Thermochemical Effects; Wear in Processing; Polymer Wear; Wear Monitoring; Wear Prevention; Boundary Lubrication; Elastohydrodynamic Lubrication; Systems Approach; Documentation of Tribology Literature.

The role of the micro environment on the tribological behavior of materials

Abstract: The properties of the environment which exert an influence upon adhesion, friction, wear, and lubrication of materials in solid state contact are discussed The effect of the environment upon lubricants and lubricant properties is considered in relation to the interaction of the lubricant with the material surfaces in solid state contact and the ability of lubricants to provide protective surface films

Friction and wear of iron-base binary alloys in sliding contact with silicon carbide in vacuum

Abstract: Multipass sliding friction experiments were conducted with various iron base binary alloys in contact with a single crystal silicon carbide surface in vacuum. Results indicate that the atomic size and concentration of alloy elements play important roles in controlling the transfer and friction properties of iron base binary alloys. Alloys having high solute concentration produce more transfer than do alloys having low solute concentration. The coefficient of friction during multipass sliding generally increases with an increase in the concentration of alloying element. The change of friction with succeeding passes after the initial pass also increases as the solute to iron, atomic radius ratio increases or decreases from unity.

Friction and wear

Abstract: Report on Tribology and physics, Institute of Physics (Midland Branch) and the Tribology Group, Department of Physics, University of Aston, 14 November 1979 at the University of Aston, Birmingham.

Material Aspects of Friction and Wear in Manufacturing Processes

Abstract: The science of tribology, which considers the effects of friction, wear, and lubrication in a coherent manner, is faced with new demands from recently developed manufacturing methods. This paper briefly reviews the major aspects of tribology from the viewpoint of their importance to the materials engineer: the special aspects of the interface, the importance of the test method selected, the phenomena in dry friction, behavior of the basic types of lubricants, and the effects of surface finish.