Ingenieurwissenschaften und zugeordnete Tätigkeiten
Filtern
Dokumenttyp
- Vortrag (2)
Sprache
- Englisch (2)
Referierte Publikation
- nein (2)
Schlagworte
- Wear behavior (2) (entfernen)
Eingeladener Vortrag
- nein (2)
The wear rates of self-mated alumina couples show that friction as well as wear is largely determined by the above mentioned hydro-thermal conditions. The presence of water and its amount available in the surrounding system either in liquid or in gaseous form plays a key role for friction and wear behavior and can be beneficial for the tribological profile of steam degradation resistant materials. Hot steam enhances the tribo-chemical formations of oxides and hydroxides on MgO-ZrO2, alumina and antimony impregnated carbon.
In the state-of-the-art technology, the impact of additives on friction and wear is evaluated in recipes with fixed concentrations. For the development of formulations it is desirable to determine the lowest effective concentration or the concentration at which failure was initiated or excessive wear began. Through a new development of the SRV® machine it is now possible to change the lubricant composition of a test specimen in a reproducible manner, in sub-pro Mill steps during the SRV® testing. This technology is used in the present article to define the optimum additive concentration with regard to wear and friction in a system of base oil and additive. Exemplary selected base oil and additive variants are tested here. The load parameters during testing are selected in such a way that they correspond to later application. The new data acquisition capabilities enable new possibilities for optimizing lubricant formulations in practice-oriented model-tribometer tests. “Cliff“ testing aims to identify in engine or gear tests the induction time or off-set point (“cliff“) after which wear and friction increased of failure occurred. Explanations for friction and wear increased as well as failures, which occurred during engine tests, can be derived from SRV® testing of oil samples taken or collected at different engine test times and correlating these with their friction, wear and EP data in respect to depleting curves for specific additives or other oil properties. A “cause-root” analysis is done by plotting SRV® data versus functional properties. The collected oil samples must be fully SRV® tested and chemically analyzed.