Process Analysis of Water Abrasive Fine Jet Structuring of Ceramic Surfaces via Design of Experiment

Machining of aluminum oxide Al2O3 can be classified as challenging by reason of its brittle and high tensile material behavior. Moreover, conventional processes for machining ceramics, e.g. using laser beam or lapping, are typically associated with lower material removal rates and high manufacturing costs. Cutting using water abrasive jet enables cutting of ceramics due to exceedingly low process forces and machining temperatures. In addition to the actual cutting process, surface structuring can be carried out using a reflecting jet by a specific adjustment of process parameters. In this context, water abrasive fine jet machining is up-and-coming due to better charge and higher precision. These factors allow the insert of the smallest geometries which either cannot be manufactured by primary shaping or are suitable for manufacturing only to a limited extent. This article describes how a process design is being executed concerning productivity and machining precision by using an analysis based on the method of the Design of Experiments (DoE). The most influencing parameters become apparent, such as water pressure, abrasive flow rate or path offset. The parameters allow a specific process dimensioning in terms of material removal rate, surface roughness and depth of penetration. Furthermore the investigations show a high reproducibility of the results using appropriate process parameters. The study illustrates that the use of the water abrasive injector fine jet permits a precise and highly efficient insertion of surface structures into ceramic materials.