It is widely recognized that ceramics are not able to run in dry friction without surface damage. It was shown that at a high level of porosity of the ceramic material, the pores in the sliding surface of mechanical seals or sliding bearings store the lubricating medium or a special lubricant, thereby enabling increased periods of dry running.
The influence of the pore shape, pore size, pore distribution and amount of porosity on the tribologic behaviour was clarified in this work. The manufacturing process of the SSiC showing this controlled porosity was optimized and a set of impregnants to be processesd in this porous material was developed. Performance in mechanical seals, water pumps and sliding bearings for magnetic couplings was assessed. Laser beam treatment was applied for the optimization of the surface structures on SSiC ceramics.
Aim of the proposed research is the development of a new technique for producing self-lubricated sintered silicon carbide (SSiC) material with a well defined porosity and infiltration. For reaching this aim, two main tasks must be carried out:
- defining of a SSiC material with optimized size, shape and distribution of pores
- evaluation of an infiltration process for this SSiC surfaces for deposition of solid lubricants.
As a consequence of the high controllability and flexibility in surface structuring the optimization of the surface porosity is carried out by laser beam treatment. in a second step, the sintering process is modified to reproduce this optimized porosity under production conditions. The major research tasks are:
- optimization of porosity by laser treatment
- investigation of the performance characteristics of the structured SSiC
- development of an infiltration technique
- modification of the production process to reproduce the optimized structure
- investigation of the properties of the new self-lubricated SSiC in seals and bearings
- field test in water pumps.
With this new material it is expected to improve the life time of SSiC components in seal and bearing applications from less than 10 minutes to more than 100 hours under dry friction conditions without serious degradation.
Funding SchemeCSC - Cost-sharing contracts
20041 Agrate Brianza Milano