Quality Control Methods of Al₂O₃ Based Ceramic Injection Molding Raw Materials

Abstract

In the illuminant industry, for producing arc tube parts for high intensity discharge lamps the applied method is the ceramic injection molding. The ceramic arc tube parts are made of high purity alumina powder. By producing ceramic parts, one of the most critical step is to optimizing the injection molding process, [1] but first of all we need to know the properties of injection molding raw material, because later the molding process will be optimized for this material, to decrease the amount of cracked ceramics.For producing ceramic arc tube parts (plugs), there are used two different major components for producing injection molding raw material (feedstock): high purity alumina powder as the main component, and an organic paraffin wax as a binder material. It is expressly important to know the material, physical and chemical properties of these components, since mainly these have affect on the homogenity of feedstock, and therefore on the quality of end product. [3]In this research, both of the main components and the moldable raw material was investigated by visual, physical, chemical and thermal methods. As most important and main statement, the researchers found that the dynamic viscosity of the injection molding raw material depends on the used mixer equipment and the applied deformation velocity.Applied analitycal methods were laser granulometry, differential thermal analysis, and rheological analysis.