INVENTORS and SCIENTISTS A MONO recently developed ,Mariaterials is an
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elasto-plastie which is to be used for inner tubes, It is said to be equal to natural rubber in resiliency, elasticity and flexibility, and will' give better service, because it neither ages nor oxidizes, whilst it. resists water, acids, alkaline solution, and temperatures up to 120 degrees C.
A plastic piston head has also been developed, and the material has been so successful that it promises to replace leather and rubber in brake systems.
A new tool alloy has been devised to fill the gap between tungsten carbide and high-speed tool steels. It is a cast chromium-tungsten-cobalt alloy, and machines all metals except chilled iron and manganese steel. It is particularly suited to nickel and chromium alloys, and speeds up production by 25-50 per cent.
Chromium plating, when deposited on the surfaces of engine cylinders, provides the hardness necessary to withstand wear.
Choke of Material
As the hardness of the bare metal under the chromium is not an important factor in cylinders, porous chromium performs just as well on soft steels and cast iron as it does on nitralloy. Therefore, if chromium plating be applied, the engine designer may choose his basic cylinder material without concerning himself about wear.
Chromium plating, furthermore, offers the advantages that its hardness exceeds that of any other available material for cylinder liners, and is maintained at high temperatures. Its thermal conductivity aids in maintaining low internal cylinder-surface temperature. Its low, friction and low affinity for other metals reduce to a minimum the heat generated at the surface, and its corrosion resistance eliminates surface deterioration resulting from the action of the products of combustion. .
ANEW type of lubricating oil, speciallY developed for use in oil engines, contains an addition serving as a detergent and oxidation inhibitor, It keeps the engine clean and gives oil stability. Carbon and dirt particles are held in suspension, and cannot be deposited inside the engine. This reduces wear of machine parts, and assures longer life to pistons and rings.
A combination of plastic and glass bearings has recently been introduced. The product consists of a plastic material reinforced with glass fibres, and is designed to replace bronze bearings. The new bearing is said to be stronger, and can take heavier loads tlaan babbitt metal..
A new process of hard-facing low-. carbon steel castings, such as lorry wheels, involves the preparation of sheets made from a suitably resistant alloy which fits into the mould. Thus, the alloy-melts and unites with the cast metal to form an integral whole.