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Miniaturization of Complex Ceramics
Published in Debasish Sarkar, Ceramic Processing, 2019
Surface grinding is a very precise machining process in which a stationary, rotating, or abrasive wheel is used to finish the surface. It can be used to finish both metallic and non-metallic workpieces. A rotating abrasive wheel gives a more refined appearance by removing oxides and impurities on the workpiece surface. The high temperatures encountered at the ground surface create residual stresses and a thin martensitic layer may form on the part surface. Examples of surface grinding processes are horizontal spindle surface grinding, vertical spindle surface grinding, and disc grinding. Finishing is one of the most important industrial processes that modifies the surface of a workpiece to achieve a notable and brilliant finish to the workpiece or job. Finishing processes improve appearance, corrosion resistance, chemical resistance, wettability, wear resistance, hardness, etc. [77]. It is also used to modify the thermal as well as the electrical conductivity of the material and controls the surface friction. Finishing is categorized into two types: adding or altering finishing includes a number of finishing processes such as calendering, blanching, cladding, corona treatment, and diffusion processes such as carburizing and nitriding, electroplating, galvanizing, case hardening, etc. Removing or reshaping finishing is done by abrasive blasting, sand blasting, electropolishing, flaw polishing, grinding, and peening such as shot peening, laser peening, buffling, and lapping.
A study of tolerance allocation and stack-up analysis to improve the assembly precision of an injection mold
Published in Journal of the Chinese Institute of Engineers, 2023
Yuo-Tern Tsai, Kuan-Hong Lin, Chun-Sheng Chen
Surface grinding can obtain very smooth faces and very precise dimensions. It is suitable for precise processing of very hard materials including the subsequent processing of the general cutting for larger chip removal such as lathe cutting or milling cutting. Surface grinding utilizes a rotational abrasive wheel for removing the material and creating a flat smooth surface. The major components of surface grinding machines have an abrasive wheel, a part-holding device using either electromagnetic or vacuum fixing as a chuck, and a reciprocating moving table. The processing precisions of surface grinding normally achieved are ±2 × 10−4 inches (5.1 μm) for a flat material and ±3 × 10−4 inches (7.6 μm) for a parallel surface (Matthew 2016). Based on the manufacturing capability, the MP of the mold is set to ±5 μm representing the quality of 3σ.
Workplace exposure to particulate matter, bio-accessible, and non-soluble metal compounds during hot work processes
Published in Journal of Occupational and Environmental Hygiene, 2019
Balázs Berlinger, Ulf Skogen, Conny Meijer, Yngvar Thomassen
“Hot work” is a term used for working with ignition sources near flammable materials, and to the extent that surface grinding of metals may cause sparks, it can also be classified as hot work. Thus, welding, flame and plasma cutting, air carbon arc gouging, and surface grinding are examples of hot work. During an arc welding process, an electric arc is created and maintained between a welding electrode and the base material to melt the metals at the point-of-contact.[1] In flame cutting, the part of the material to be cut is raised to ignition temperature by an oxygen-fuel (e.g., acetylene) gas flame.[2] During plasma cutting, an arc is formed between the electrode and the workpiece, which is constricted by a fine bore, copper nozzle. The plasma gas flow is increased so that the deeply penetrating plasma jet cuts through the material, and molten material is removed in the efflux plasma.[3] During air carbon arc gouging, an electric arc is generated between the tip of a copper-coated graphite electrode and the workpiece. The molten metal is blown away by high velocity air jet streams. This is an effective process to clean metal surfaces.[4] Surface grinding is used to plane the surface of a workpiece, remove surface coatings, mistakes, or excess material. A grinding wheel of aluminum oxide or silicon carbide is usually used in this process.[5]