Wear of tyres of belt and diagonal construction

carbide, had a hardness between VHN = 500 and 2700 kgf/mm’. For the wear of pure metals and carbon steels low/high-level characteristics were found; for the nonmetallic materials somewhat different courses resulted. Besides the influence of material hardness and modulus of elasticity, the effects of cold working and age hardening were tested in the case of a copper-beryllium alloy. In addition, there was some research on the effect of a higher content of residual austenitc for steels. For different wear mechanisms aqueous solutions as contacting medium with pHvalues of 5 to 7.5 also have a different effect. Surface films formed in normal atmosphere cause partially dissimilar amounts of wear in respect to the behaviour in a vacuum of about IO-J tori-. The film formation is dependent on the cold working of the material. Further results concern the dependence of blasting wear on blast angle, particle hardness, velocity of impact and surrounding gas atmosphere. See also l+‘ear, II (1968) 173. Phenomena During Impact Loading and Their Relationship to Wear Processes. G. Gommel, Materialpviif., 9 (5) (1907) 175-178; 8 figs., II refs. Single- and multiple-impact tests were carried out on rotating wheel equipment within a velocity range from 45 to 70 mjsec and with r-mm steel balls and cut steel wire shot respectively. The hardness of the impacting pair ball/plate varies between 200 and 800 kgf/mm” VHN. Energy absorption of plate and wear are dependent on hardness and impact speed. Temperature rise and electric charging during impact, as well as change of structure including the formation of oxide films at the impact point can be observed. Influence of Oxide Films on Friction and Wear During Sliding. A. Vy. J. de Gee, ~~~~e~~u~~~~~., 9 (5) (1967) 166-169; 7 figs., 8 refs. Comparatively thick oxide films generally inhibit the formation of adhesive joints between the sliding surfaces and, thus, reduce friction and wear. However, in some cases introduction of oxygen may well increase the adhesion between sliding surfaces, clue to the formation of monomolecular oxide films, which locally glue the surfaces together. This is illustrated on the basis of results obtained with the silver/iron friction couple. See also Wear, 5 (1962.) 257; 8 (rgG5) 121. The Wear of Cutting Tools and Possibilities for Its Reduction. Materitmlpr%$., 9 {5) (1967) W. Klinig, ‘70-174; 9 figs., 9 refs. High mechanical stresses and temperatures Iead to definite phenomena of tool wear. The

basis for efficient steps in reducing tool wear is the knowledge of its causes. :\ccording to the cutting temperatures different influences become dominant : mechanical abrasion, micro-crumbling due to the separation of pressure weldings, diffusion and oxidation, ovcrmechanical or mechanical-thermal loading of the cutting edges. The application of wear-reducing surface layers and mctallurgical measures in steel melting which lead to a deposition of wear-reducing oxide-layers in the contact zones offer possibilities for reducing tool wear. Test Bench for Wear Measurement in Internal Combustion Engines by means of Radioactive Indicators. r. J. MCiller, ~~~~~~i~l~~ij~., 9 (5) (rgo7) 179-183; 5 figs., 2 tables, 9 refs. The equipment consists of a test engine, an automatically operated device for taking samples, a radiation detector and protection against radiation. The conduction of measurements is shown using tappet wear measurements as an example including the necessary calculations. The Present State of Friction and Wear Research. G. Salomon, Materialprz'if., 9 (5) (1967) 183-184; 4 refs. Classification Problems in the Field of Wear. I(. Ilirschke, Mute~~u~~~~f., 9 (5) (1967) 1855187; I table, 3 refs. See also Wear, IO (1967) 418. Wear Problems with Motor Vehicles. E. Kruppke, Materialprtif., 9 (5) (1967) 188%Igo; 5 figs., I table, 2 refs. Wear of Tyres of Belt and Diagonal Construction. MateriaZ$vtif., 9 (5) {x967) R. Stender, 191-193; 5 figs., I table. Wear Tests on Organic Floor Coverings. ~~~e~~~~~4~~.I 9 (5) (1967) F’. Jagfeld, 193-196; 4 figs., 2 tables, f refs. Wear Tests on Textiles to Assess Performance and Durability. Materialpdf., 9 (5) (1967) G. Satlow, Ig7--201; 0 figs., I table, 37 refs. The Area Between Wear and Catastrophical Destruction of Conveying Equipment Used in Brown Coal Mining. R. Oettel, MateriaZ@r@., 9 (5) (1967) 202-204; 4 figs., 4 refs. Mechanical Properties and Resistance to Wear of Steels Used for Crushing Tools. H. Berns, Mute7~aZ~r~f., 9 (5) (1967) 204--206; 5 figs., 2 tables, 2 refs.