Center of excellence in research 483

Teilprojekt T2

Practical aspects of sialon ceramics

Prof. Dr. rer. nat. Michael J. Hoffmann 
Institut für Angewandte Materialien (IAM-KM) 
Karlsruher Institut für Technologie 

Transfer project T2 is conducted in collaboration with “Ceramtec” corporation. Its target is to transfer results generated in project B1 „ceramic materials for applications in high stressed sliding systems” to industrial applications. Focus is on the application of Sialon materials, testing methods for lifetime prediction and treatments for the improvement of coating adhesion  with the  following goals:

  • Improvement of lifetime prediction for statically stressed ceramics by means of adapted test procedures.
  • Estimation of the potential of Sialon ceramics for application as prostheses.
  • Improvement of coating adhesion on sialon cutting tools by surface modifications.

 

 Different ways to determine subcritical crack growth (dynamic/static) and sample geometries (4-p-bending, ball on 3 ball, ring on ring) will be investigated and compared. Furthermore, commercial oxide and nitride ceramics by the project partner are characterized and compared to sialon ceramics generated within the project. Residual strength measurements on tribologically stressed samples will be carried out in an attempt to clarify how the typical fretting behaviour in prostheses influences the endurance strength of these materials.

In order improve adhesion of CVD/PVD coatings, the surface of sialon ceramics is modified by means of plasma etching and a heat treatment respectively. Thus treated samples are coated by the cooperation partner and layer thickness and adhesion are estimated. Finally, some chipping tests will be performed on the coated cutting tools.