Perspectives for Wear Reduction with Ceramic Extruder Components

Against the background of the very high wear of the contact material surfaces, ceramics with their outstanding wear properties are ideally suited to application in extrusion processes. Thanks to their high wear resistance, it is possible to reduce machine downtime, metal contamination of the product as well as the torque moment. The application of ceramic components requires a new mindset of the design engineers because they also have to take into account the typical disadvantages of ceramics, like pure linear material behaviour, limited breaking elongation and statistical fracture behaviour including size effect. It is essential to apply a material-suitable module and joining technique to withstand the complex collective stresses. For the ceramic components, it is necessary to determine the mechanical, thermal and chemical loads to which they are exposed in use. For analysis of the stress field, FEA (Finite-Element-Analysis) is a suitable tool to calculate specific stress distributions. In the next step, the stress distributions (axial and torque loads) are superposed to get an idea of the entire stress field. Furthermore with FEA, it is possible to calculate the tension-stressed volume (Veff) for these geometrically complex components, enabling calculation of the fracture probabilities according to the Weibull theory.