Additive Name given to petroleum oils compounded with chemical addition agents to enhance certain properties such as detergency, antioxidant characteristics, etc. or any material added to a lubricating grease or lubricating oil to improve its suitability for service. It may improve a property already possessed by the lubricant, or give it properties not naturally possessed. Typical examples are antioxidants, EP agents or anti wear additives. Adhesive Wear
Wear caused by metal-to-metal contact; characterised by local welding and tearing of the surface. Alkali Any substance having basic properties (as contrasted with acid properties). In a restricted sense in grease manufacture, this term is applied to the hydroxides of the alkali metals, including lithium, sodium, calcium and other metal ions. Alloy A substance having metallic properties, containing two or more chemical elements, at least one of which is metal. The substance usually has qualities different from those of the individual components. Alumina Oxide of aluminium. Usually produced from bauxite as a first stage in the manufacture of aluminium. About two tons of alumina make one ton of metal. Also a refractory and an abrasive. Aluminium Used to deoxidize steel and control grain size with additions up to around 0.05 wt. percent. Grain size control is accomplished by the formation of a fine dispersion of aluminum nitride precipitates, which restricts austenite grain growth. Aluminum can be added at higher levels as an effective nitride former in nitriding steels. Amorphous A term applied to such materials as carbon black, as contrasted with such crystalline materials as graphite or Molybdenum Disulfide. Anti – Foam Agent An additive used to suppress the foaming tendency of petroleum products in service. May be a silicone oil to break up surface bubbles or a polymer to decrease the number of small entrained bubbles. Ash Metallic deposits formed in the combustion chamber and other engine parts during high temperature operation Assay The independent evaluation of the physicochemical composition of a metal or alloy to determine its degree of purity. Also to establish the metal content of ore or scrap. Also international standards, and some standards peculiar to futures market contracts, specify metal contents and maximum levels of impurity. Metals and ores are assayed to establish if they meet these. |
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