Abstract: Abrasion testing, and hence particle content of fluids including liquids and gases is carried out by abrading a thin film 25 of an electrical conductor with the fluid, and measuring the resulting change in electrical resistance of the film.The method can be used to monitor metal particles in oil, and hence the state of wear of oil-lubricated metal parts, and the level of particulate pollution in the atmosphere.

Abstract: A process of diffusion bonding aluminium alloy parts uses zinc and copper layers, optionally with a tin layer, or magnesium and/or zinc layers as an interlayer material between the parts to be bonded. The interlayer is preferably formed by precoating one or both of the parts.

Abstract: A method of making a heat-recoverable article which comprises cooling an article in a first shape from a first temperature to a lower temperature, said article being formed from an alloy comprising at least one phase in the form of a primary solid solution of a first metal with at least one other metallic element which increases the stability of a high temperature phase of the first metal, which solution on cooling from said first temperature retains the high temperature phase but which transforms into an essentially banded martensite phase on cold working and then plastically deforming the article into a second shape, the temperature and rate of cooling being such that, on reheating, the article at least partly resumes said first shape.

Abstract: A method of making a heat-recoverable article which comprises cooling an article in a first shape from a first temperature to a lower temperature, said article being formed from an alloy comprising at least one phase in the form of a primary solid solution of a first metal with at least one other metallic element, which solution on cooling from said first temperature either (1) at least partially transforms into an essentially bonded martensite or (2) retains the high temperature phase but which transforms to an essentially bonded martensite on cold working, and then deforming the article into a second shape, the temperature and rate of cooling being such that, on reheating, the article at least partly resumes the first shape.

Abstract: A method of making a heat-recoverable article in which an alloy comprising an intermetallic compound, which on cooling transforms into a banded martensite by shear with or without working, deformed after appropriate heat treatment so that on reheating it at least partly resumes its original shape. It is preferred to use a copperbase alloy which transforms into a martensite of pseudocubic symmetry.