![]() The source of power for solid-state processes is the change in free or chemical potential energy between the neck and the surface of the particle. At steady state, the particle radius and the vapor pressure are proportional to (p 0) 2/3 and to (p 0) 1/3, respectively. To yield the desired bond area, temperature and initial grain size are precisely controlled over the sintering process. The ratio of bond area to particle size is a determining factor for properties such as strength and electrical conductivity. The change in energy is much higher when the radius of curvature is less than a few micrometers, which is one of the main reasons why much ceramic technology is based on the use of fine-particle materials. If the size of the particle is small (and its curvature is high), these effects become very large in magnitude. On a microscopic scale, material transfer is affected by the change in pressure and differences in free energy across the curved surface. It forms new but lower-energy solid-solid interfaces with a net decrease in total free energy. The driving force for densification is the change in free energy from the decrease in surface area and lowering of the surface free energy by the replacement of solid-vapor interfaces. During the firing process, atomic diffusion drives powder surface elimination in different stages, starting at the formation of necks between powders to final elimination of small pores at the end of the process. in filters or catalysts, where gas absorbency is a priority). In some special cases, sintering is carefully applied to enhance the strength of a material while preserving porosity (e.g. Sintering is generally considered successful when the process reduces porosity and enhances properties such as strength, electrical conductivity, translucency and thermal conductivity. General sintering Cross section of a sintering tool and the sintered part The word sinter comes from the Middle High German sinter, a cognate of English cinder. The material produced by sintering is called sinter. Examples of pressure-driven sintering are the compacting of snowfall to a glacier, or the formation of a hard snowball by pressing loose snow together. The study of sintering in metallurgical powder-related processes is known as powder metallurgy.Īn example of sintering can be observed when ice cubes in a glass of water adhere to each other, which is driven by the temperature difference between the water and the ice. Since the sintering temperature does not have to reach the melting point of the material, sintering is often chosen as the shaping process for materials with extremely high melting points, such as tungsten and molybdenum. The nanoparticles in the sintered material diffuse across the boundaries of the particles, fusing the particles together and creating a solid piece. ![]() ![]() Sintering happens as part of a manufacturing process used with metals, ceramics, plastics, and other materials. ![]() Sintering or frittage is the process of compacting and forming a solid mass of material by pressure or heat without melting it to the point of liquefaction. Heat and compaction fuse small particles into a dense bulk Clinker nodules produced by sintering ( October 2022) ( Learn how and when to remove this template message) Please help to improve this article by introducing more precise citations. This article includes a list of references, related reading, or external links, but its sources remain unclear because it lacks inline citations. ![]()
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