Download or read book Evidence for the Melt Lubrication of Projectile Bands written by and published by . This book was released on 1983 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt: Despite the long-time acceptance of melt-lubrication of rotating bands by the Army scientific community, all of the evidence supporting this conclusion has not been collected and, indeed, some has never been published. The melt-lubrication of rotating bands is very important because the sliding is lubricated and friction and wear are determined only by the characteristics of the molten film and the amount of melting at the sliding interface. Melt- lubrication results in much less resistance and much less severe wear than would otherwise be the case. Friction, wear and metallographic evidence from examination of recovered projectiles and fired cannon tubes show the melt- lubrication of projectiles sliding on a gun bore. This melt-lubrication is caused by the production of a thin surface film of molten rotating band material. Such a molten surface layer can also be produced on the surface of materials other than copper alloys contacting the bore at high bearing loads.
Download or read book Projectile Lubrication by Melting Rotating Bands written by and published by . This book was released on 1976 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sliding experiments carried out in the laboratory with a pin-on-disk machine produced appreciably higher coefficients of friction than the actual values measured for projectiles sliding down cannon bores. Although the pin surface melted, the coefficient of friction was at least an order of magnitude higher than expected for liquid film lubrication. The sliders in the laboratory experiments were, of course, much smaller than actual rotating bands and the bearing pressure was limited by distortion of the sliding pin.
Download or read book The Kolsky Hopkinson Bar Machine written by Ramzi Othman and published by Springer. This book was released on 2018-04-20 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book, leading scientists share their vision on the Kolsky-Hopkinson bar technique, which is a well-established experimental technique widely used to characterize materials and structures under dynamic, impact and explosion loads. Indeed, the Kolsky-Hopkinson bar machine is not a simple experimental device. It is rather a philosophical approach to solve the problem of measuring impact events. The split Hopkinson pressure bar conventional device is mainly limited to test homogeneous ductile non-soft materials under uni-axial compression. Extending the use of this device to more versatile applications faces several challenges such as controlling the stress state within the specimen and mastering the measurement of forces and velocities at the specimen-bar interfaces and then the material properties. Thus, the topics discussed in this book mainly focused on the loading and processing parts.
Download or read book Lubrication Engineering written by and published by . This book was released on 1984 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Wear of Projectile Rotating Bands written by R. S. Montgomery and published by . This book was released on 1985 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rotating or driving bands are bands relatively soft materials surrounding a projectile. They have a number of functions the chief of which is probably that they produce stabilizing rotating of the projectile when they are engraved or keyed into the rifling. These bands are used on spin-stabilized projectiles as small as 20 mm caliber, but this discussion concerns especially the larger cannon, i.e., in excess of 105 mm. Excess wear of projectile rotating bands has a number of important negative consequences including inaccuracy and short rounds. There are two distinctly different mechanisms of wear. At low speeds near the beginning of motion, wear is by adhesion, abrasion, and even under some conditions, scuffing. After a few centimeters of sliding, a thin surface film of molten band material is formed and the remainder of the sliding is melt-lubricated. While metal-on-metal sliding is limited to the first few centimeters, it is very important and can result in serious wear problems down bore. The exact wear of rotating bands depends on the motion of the projectile in the bore of the cannon. Therefore, this motion can be inferred from the wear.
Download or read book Metals Abstracts written by and published by . This book was released on 1992 with total page 1516 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Surface Melting of Rotating Bands written by and published by . This book was released on 1975 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: The point at which a complete molten film is formed on the surface of projectile rotating bands is very important because, when it is formed, sliding becomes lubricated and friction determined by hydrodynamic considerations alone. Furthermore, beyond this point, wear of a particular band material is dependent only on the amount of heat transferred to it. The first formation of the molten surface film for projectiles with gilding metal bands was estimated by observing the location of the drop in the coefficient of friction. This was reached well before the bands were completely engraved in the case of a 155mm howitzer firing at low zones. It would be reached even more rapidly in the case of tank guns or artillery firing at higher zones.
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1984 with total page 1268 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Annual Index written by and published by . This book was released on 1984 with total page 1084 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sections 1-2. Keyword Index.--Section 3. Personal author index.--Section 4. Corporate author index.-- Section 5. Contract/grant number index, NTIS order/report number index 1-E.--Section 6. NTIS order/report number index F-Z.
Download or read book Government Reports Annual Index Keyword A L written by and published by . This book was released on 1984 with total page 1092 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metals Abstracts Index written by and published by . This book was released on 1984 with total page 1034 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Erosion in Large Gun Barrels written by and published by National Academies. This book was released on 1975-01-15 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: Confronted with problems associated with the continual upgrading of field guns, reducing the number of different items in supply and lowering overall costs, the Department of the Army has need for improved methods of reducing erosion and extending the wear life of long range cannon. The National Materials Advisory Board was asked to consider all facets of this need and to make recommendations. Erosion in Large Gun Barrels assesses the nature of the bore erosion problem; identifies fruitful areas of research; assesses the state of technology of materials and methods in areas which may become significant to gun tubes of improved performance; and suggests experimental techniques, devices, and instruments and methods of reducing data to enhance the continuing coordination of the activities of the three Services.
Download or read book Alloys Index written by and published by . This book was released on 1984 with total page 990 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Journal of the Faculty of Engineering University of Tokyo written by and published by . This book was released on 1917 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 692 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Journal of the Faculty of Engineering University of Tokyo written by Tōkyō Daigaku. Kōgakubu and published by . This book was released on 1917 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Journal of the College of Engineering Tokyo Imperial University Japan written by Tōkyō Daigaku. Kōgakubu and published by . This book was released on 1917 with total page 850 pages. Available in PDF, EPUB and Kindle. Book excerpt:
