Machining theory for grinding fiber-reinforced non-oxide ceramics

 

The demand for lightweight construction leads to a constant further development of the construction materials. Due to a limited further development potential regarding the thermal load capacity of metallic superalloys, fibre-reinforced ceramics have become the focus of material developments. Due to their high mechanical stability, high damage tolerance, thermal resistance and low density, fibre-reinforced ceramics represent a material group with a very high application potential.

Ceramics are classified as non-oxide ceramics and oxide ceramics. Non-oxide ceramics have a higher hardness and strength than oxide ceramics due to the increased proportion of covalent and ionic bonds. The machining mechanisms of fiber-reinforced oxide ceramics with porous matrix have already been investigated. Silicon carbide ceramics, reinforced with C or SiC fibers, represent the types of fiber-reinforced non-oxide ceramics with the highest application significance. However, the cutting mechanisms used in the grinding of fiber-reinforced non-oxide ceramics are only insufficiently known, so that a prediction of the process result is not yet possible. Therefore, complex preliminary tests have to be carried out. In particular, the influence of fiber orientation on the cutting mechanisms and the interaction between matrix and fiber during grinding have not yet been analyzed in detail.

The overall goal of the project is to develop a heuristic explanatory model for the machining mechanisms in the grinding of fiber-reinforced non-oxide ceramics.