Surface topography and functional morphology analysis of micro-abrasive blasted mould surface for improved ceramic injection molding performance

Structuring of mould surfaces is a topic of high interest for both industry and academia. The engineering of mould surface can enable improved functionality and performance. For instance, structured surfaces have been reported to exhibit reduced melt flow resistance, reduced interfacial friction, and better filling of the mould cavity thereby enabling use of low pressures and drag reduction. Several structuring techniques have been proposed such as laser induced periodic surface structures (LIPSS), surface structuring by electrical discharge machining (EDM) and electrochemical machining (ECM), micro-abrasive blasting (sand blasting) as well as coating techniques (Diamond-like carbon, TiN, TiAlN, etc). In this work, prototype ceramic injection moulds were subjected to two types of micro-abrasive blasting operations (i) blasting with alumina (Al2O3) (ii) blasting first with alumina and thereafter with zirconia (ZrO2) both aiming at improving ceramic injection molding. It was observed that the standard height based roughness/surface parameters are not sufficient to distinguish between both surfaces and to give information on functional performance. Therefore, hybrid parameters (Sdq, Sdr) were evaluated to characterize the surfaces using an atomic force microscope (AFM) and a Mitutoyo(R) Formtracer. Their functional surface morphology is analyzed using scanning electron microscopy. Further work involves generation of these surface structures on the mould surface using micro-EDM/laser/micro-ECM.status: publishe