Annealing (metallurgy) brass can be cooled slowly in air, or quickly by quenching in water, unlike ferrous metals, such as steel, which must be cooled slowly to anneal. In this fashion, the metal is softened and prepared for further work—such as shaping, stamping, or forming. Annealing occurs by the diffusion of atoms within a solid material, so that the material progresses towards its equilibrium state. Heat increases the rate of diffusion by providing the energy needed to break bonds. The movement of atoms has the effect of redistributing and eradicating the dislocations in metals and (to a lesser extent) in ceramics. This
Glass knife Glass knife A glass knife is a knife with a blade composed of glass. The cutting edge of a glass knife is formed from a fracture line, and is extremely sharp. Glass knives were used in antiquity due to their natural sharpness and the ease with which they could be manufactured. In modern electron microscopy, glass knives are used to make the ultrathin sections needed for imaging. Beginning in the Stone Age, glass knives (and other tools, such as arrowheads) were produced through a process known as knapping or lithic reduction. Although such bladed tools were often made of stone,