The primary objective is the development of an improvement process for producing near net-shaped components from advanced ceramics using injection moulding.
An improved process for making ceramic parts by injection moulding has been developed. This has been achieved with the aid of a new temporary thermoplastic binder system with advantageous debindering characteristics, a specifically adapted alumina powder and optimized binder removal procedures. Parts with wall thicknesses up to 4 mm can now be made using a thermal debindering cycle of less than 24 hours. Several different demonstration components were made exhibiting dimensional tolerances below 0.5%, a surface finish with Ra=0.2 um and an as fired MOR of 385 MPa.
The process enables the high volume production of complex shaped advanced ceramic parts at low cost.
An improved process for making ceramic parts by injection moulding has been developed. Rheological measurements, thermogravimetric analysis and practical moulding trials coupled with advanced nondestructive evaluation of moulded parts have been used to improve an existing and develop a new binder system using empirical methods. Several complex shaped alumina components were made. A good surface finish with R a = 0.2 um and 4-point modulus of rupture (MOR) of 385 MPa on as-fired specimens were obtained. Dimensional tolerances in production of +/- 0.5% are predicted.
This will be achieved by:
-the development of a temporary organic binder system with improved burnout characteristics, which is capable of imparting the required rheological properties to the moulding mix
-the synthesis of advanced oxide ceramic powders with characteristics specifically adapted to injection moulding
-the development of optimized binder removal procedures
-the establishment of a data for mould design.
The project is expected to enable the high volume production of complex-shaped advanced ceramics at low cost.