Filtern
Dokumenttyp
- Beitrag zu einem Tagungsband (3) (entfernen)
Sprache
- Englisch (3)
Schlagworte
- Ceramics (3) (entfernen)
Stick-slip and wear behavior of ceramic and polymer materials under reciprocating sliding conditions
(2013)
In many technical applications not only the actual friction coefficient is of importance, but rather the constancy relevant for the functionality. Due to inconstant ffiction values, positioning processes can be substantially influenced as well as vibrations can be induced. The appearance of this tribological effect, named stick-slip, depends on different factors such as sliding speed, relative humidity and ambient temperature occurring primarily after long operating periods. Beside ambient conditions the choice of materials in contact is the main influencing factor of an inconstant coefficient of friction during operating. Certain polymers are well known for their stick-slip tendencies in technical applications. These are on the one hand different modifications of PTFE (polytetrafluoroethylene) reinforced with glass fibers, bronze or graphite and on the other hand thermoplastics such as PE (polyester) or Pf (polyimide). The difference between static and dynamic values of the ffiction force is decisive for stick-slip phenomena. Furthermore, the stick-slip tendency of polymers strongly depends on the elastic material properties. Main softening material areas, which can be found in the contact, represent particularly vulnerable areas. The high friction value in the contact area decreases in most cases by increasing sliding speeds. However, beside polymers ceramic materials can also offer tendencies to stick-slip motion. Klaffke et al. already investigated the influence of ceramic materials on the stick-slip behavior in.
The influence of temperature and counterbody material on the tribological properties of a-C:H
coatings deposited on Cronidur 30 steel has been investigated in a lubricated ball on disk
contact situation with alpha-alumina and silicon nitride as counterbodies. The results show, that the wear volumes of the systems increase exponentially with increasing temperature, for alpha-alumina more than for silicon nitride. Two different wear mechanisms seem to have a
major influence: First, the abrasive action due to materials hardness and second, the tribo-oxidation when silicon nitride is counter material.
The influence of temperature and counterbody material on the tribological properties of a-C:H coatings deposited on Cronidur 30 steel has been investigated in a lubricated ball on disk contact situation. The results show, that the wear volumes of the system increase exponentially with increasing temperature. Two different wear mechanisms seem to have a major influence: First, the abrasive action due to materials hardness and second, the tribooxidation when silicon nitride is counter material.