Investments for casting micro parts with base alloys

The production of micro parts made of alloys like Al-bronze by casting techniques requires specially designed investments with sufficient mechanical and thermal stability. For damage free deflasking, good solubility of at least one component of the burned mold is required. Furthermore, especially when the micro parts are meant to mechanically interact with each other in a micro system, the surface roughness of the micro parts has to be as low as possible. With phosphate-based investments damages caused by mechanical removal of the investment cannot be avoided. Therefore, other systems that allow chemical removal of the investment have to be developed. An investment based on hard plaster loaded with fine-grained quartz powder and good chemical removability was investigated. The results showing the high performance of the optimized system will be presented.