Slip casting of ceramic microcomponents

Casting of ceramic microcomponents is an interesting alternative to the molding of ceramic filled polymers, if a fast, flexible and inexpensive process is required. Although casting is less suited for mass production, it is a promising way for the production of small numbers of parts, e.g. for experimental prototypes. As conventional slip casting is unsuited for the shaping of microcomponents, particular casting methods, like slip pressing or centrifugal casting, have been developed. Although these techniques also need templates, their manufacturing is less expensive than the manufacturing of the injection molding tool. With the described processes, structures have been prepared with lateral detail dimensions of about 20 μm and aspect ratios of more than 10. Al2O3 and piezoelectric Pb-Zr-Ti oxide (PZT) have been shaped as microcomponents, but the processes can be applied to other ceramic materials. Due to some limitations each process should be used in its optimized application fields. Slip pressing requires low compaction pressures. Therefore it is best suited for the patterning of disk-like substrates, while slip pressing of thick samples may become rather time consuming. Centrifugal casting is limited in the lateral dimensions, caused by the rotor dimensions, however it allows the fabrication of thicker parts. By using wax lost molds this process is economical and well suited for a large variety of ceramic materials and shapes.