Filtern
Erscheinungsjahr
Dokumenttyp
- Zeitschriftenartikel (66)
- Beitrag zu einem Sammelband (47)
- Beitrag zu einem Tagungsband (18)
- Vortrag (8)
- Forschungsbericht (3)
Sprache
- Englisch (81)
- Deutsch (59)
- Mehrsprachig (2)
Schlagworte
- Friction (20)
- Wear (18)
- Reibung (11)
- Tribologie (11)
- Relative humidity (9)
- Silicon carbide (8)
- Verschleiß (8)
- Luftfeuchte (6)
- Humidity (5)
- Keramik (5)
- DLC (4)
- Fretting (4)
- Luftfeuchte Fretting (4)
- Reciprocating sliding (4)
- CVD (3)
- Kleine Lasten und Amplituden (3)
- Oscillating sliding (3)
- Schwingungsverschleiß (3)
- Stainless steel (3)
- Temperature (3)
- Titanium carbide (3)
- Titanium diboride (3)
- Water lubrication (3)
- Alumina (2)
- Bearbeitbarkeit (2)
- Ceramic (2)
- Ceramics (2)
- Coating (2)
- Dentalkeramik (2)
- Diamond (2)
- Gleitbewegung (2)
- Kohlenstoffschichten (2)
- Lubrication (2)
- Normal force (2)
- Normalkraft (2)
- Role reversal (2)
- Salzwasser (2)
- Silicon nitride (2)
- Temperatur (2)
- Verschleiss (2)
- Vibrating contacts (2)
- Wear quantities (2)
- AFM (1)
- Abriebverhalten (1)
- Acoustic emission (1)
- Adhesion (1)
- Alcaline earth fluorides (1)
- Aluminium (1)
- Ball-on-disk (1)
- Bearing steel (1)
- Beschichtung (1)
- Biegung (1)
- Ca-Ba fluoride (1)
- Calcium titanate (1)
- Calciumtitanat (1)
- Carbon coating (1)
- Ceramic Composites (1)
- Ceramic composites (1)
- Chemical vapour deposition (1)
- Coating, debris (1)
- Composits (1)
- Connector coatings (1)
- Contact failure (1)
- Contact resistance (1)
- Corundum (1)
- Counter body (1)
- Counter body material (1)
- Counterbody (1)
- Counterbody material (1)
- Cytokines (1)
- DLC-Beschichtung (1)
- DLC-Schichten (1)
- DLC-coatings (1)
- Database (1)
- Debris (1)
- Dental ceramic (1)
- Depth-sensing indentation (1)
- Diamant (1)
- Diamant-Beschichtungen (1)
- Diamond coatings (1)
- Diamond-like carbon (1)
- Dispersing behavior of particles (1)
- Dry-slidins (1)
- Dünne Drähte (1)
- EDX (1)
- Eigenschaft, mechanisch (1)
- Electrical current (1)
- Elektrischer Widerstand (1)
- Feuchte (1)
- Frequency (1)
- Fretting corrosion (1)
- Friction test (1)
- Gegenkörperwerkstoff (1)
- Gleitverschleißverhalten (1)
- Hard coatings (1)
- High temperatures (1)
- Hip joint endoprostheses (1)
- Humidity water (1)
- IWM (1)
- Implant (1)
- Infiltration (1)
- Kohlenstoff-Schichten (1)
- Kohlenstoffschicht, amorph (1)
- Kompositkeramik (1)
- Kontaktmechanik (1)
- Korrosion (1)
- LRS (1)
- Laserstrahlbearbeitung (1)
- Life time (1)
- Liquid media (1)
- Load (1)
- Luftfeuchtigkeit (1)
- MW PACVD (1)
- Machinability (1)
- Macrophages (1)
- Mating material (1)
- Mechanical properties (1)
- Metalldotierung (1)
- Metalle (1)
- Microparticles (MP) (1)
- Model particles (1)
- Model testing (1)
- Nano-particles (1)
- Nanoparticles (NP) (1)
- Oberflächenbehandeln (1)
- Oberflächentopographie (1)
- Operational parameters (1)
- Oscillating Sliding (1)
- Oscillating sliding test (1)
- Oscillation sliding (1)
- PECVD (1)
- Parameter effects (1)
- Particle size distribution (1)
- Particulate composite (1)
- Particulate composites (1)
- Polieren (1)
- Polishing (1)
- Porous zirconia (1)
- Preceramic polymer (1)
- Raman-Laser (1)
- Raman-Mikroskopie (1)
- Randzone (1)
- Rasterelektronenmikroskopie (1)
- Reibungsverhalten (1)
- Reproduzierbarkeit (1)
- Rostfreier Stahl (1)
- Roughness (1)
- Running in (1)
- Running-in (1)
- SEM (1)
- SSiC (1)
- Schallemission (1)
- Scherenergiedichte (1)
- Schmierstoff (1)
- Schwingungsverschleiss (1)
- Si3N4 coating (1)
- SiC (1)
- SiO2 coating (1)
- Siliconcarbonitride (1)
- Siliziumkarbid (1)
- Slip-rolling (1)
- Solid lubrication (1)
- Steel (1)
- Steel couples (1)
- Steel/diamond pairings (1)
- Stickstoff (1)
- Stroke (1)
- Surface analysis (1)
- Surfaces (1)
- TEM (1)
- Test methods (1)
- Testdauer (1)
- Thermal resistance (1)
- Third body (1)
- Ti-6Al-4V (1)
- TiB2 (1)
- TiC (1)
- TiN (1)
- Titan Stickstoff (1)
- Titanium (1)
- Titanium alloy (1)
- Titanium boride (1)
- Titanlegierung (1)
- Topography (1)
- Transfer layer (1)
- Tribo-oxidation (1)
- Tribobeanspruchung bei reversierendem Gleiten (1)
- Tribokorrosion (1)
- Tribology (1)
- Tribooxidation (1)
- Tribotesting (1)
- Unlubricated friction (1)
- Vakuum (1)
- Verbundwerkstoffe (1)
- Verformung (1)
- Verschleißprognose (1)
- Verschleißverhalten (1)
- Wear debris (1)
- Wear infiltration (1)
- Wear particle (1)
- Wear particles (1)
- Wear products (1)
- Wear scar (1)
- Wires (1)
- Zirconia (1)
- Zwischenmedium (1)
- pH-Wert (1)
- pH-value (1)
- ta-C coatings (1)
Eingeladener Vortrag
- nein (8)
Tribological screening tests (simple, reciprocating ball-on-flat tests) were performed with the objective to identify an appropriate coating for the articulating surfaces of artificial hip joints whose acetabular cups and femoral stems are made from Ti6Al4V alloy, which is appreciated for its light weight, good biocompatibility and elastic properties similar to those of natural bone. Standard coatings like TiN or CrN performed better than more complicated multi-layer systems, though not as good as different types of amorphous carbon coatings, generally referred to as diamond-like carbon or DLC coatings. Among the latter, hydrogenated amorphous carbon (a-C:H) displayed the best properties, especially if the hydrogen content was increased by reducing the bias voltage during PA-CVD-deposition.
The optimised a-C:H coating revealed the most promising wear behaviour under the applied testing conditions, i.e. the increase of linear wear with the number of cycles was close to zero. Regarding the materials examined in this study, correlation of wear with mechanical properties obtained by nano-indentation revealed that high hardness was not an adequate criterion for selecting appropriate coatings. A high ratio of hardness and elastic modulus (H/E) proved to be more important. Microstructural and micro-analytical investigations revealed transformation of TiN and CrN to TiO2 and Cr2O3, respectively, and amorphous carbon was, at least partly, transformed to graphite. Furthermore, incorporation of Al2O3 from the ball was observed at a very fine scale. The wear debris of favourable coatings always formed agglomerates of nano-scale particles. It was shown that commercial nano-particles of Al2O3, Cr2O3 and carbon black are comparable to particles generated by the tribological tests. However, it is uncertain whether they are comparable to those formed during simulator studies or in vivo. Furthermore, the performance of the favourable coating has to be tested in a hip joint simulator before its potential for application in prostheses can be assessed.
An attempt was undertaken to obtain a better understanding of the tribological properties of two wear-resistant coatings on tool steel by structural and microchemical analysis of wear particles using a transmission electron microscope. Coatings were deposited by physical vapor deposition and plasma-assisted chemical vapor deposition techniques and tribological properties were derived from reciprocating sliding tests of the coatings against alumina balls. Three types of wear particles were identified by electron diffraction and energy dispersive X-ray spectroscopy: nanocrystalline rutile (TiO2), nanocrystalline graphite and microcrystalline graphite. Low coefficients of friction, of the order of 0.2, were attributed to the formation of solid lubricant films of sub-stoichiometric TiO2-x Magnéli phases and/or graphite.
The tribological behaviour of different monolithic and composite ceramics was evaluated in the temperature range between room temperature and 750°C. The test method was oscillating sliding with a ball-on-disk arrangement in an SRV machine. Alumina balls were used as counter body. The friction behaviour was determined on-line, and the wear behaviour was determined from calculations on the basis of wear scar dimensions and profilometric measurements. The friction depends on temperature and shows an increase for most materials for increasing temperature; the smallest friction at all temperatures is found for monolithic TiC. The wear behaviour shows different trends for the different materials. In tests against SiC a maximum of wear is found at 500°C, for TiC at 200°C and for TiB2 at 750°C. The composite ceramics suffer the smallest wear of all materials in the range from 200°C to 500°C.
COMPOSITE MATERIALS OF A 99.7 % ALPHA-ALUMINA MATRIX WITH PLATELETS OF SILICON CARBIDE (SICP) HAVE BEEN PREPARED BY GELCASTING. DENSIFICATION WAS CARRIED OUT BY GAS-PRESSURE SINTERING WITHOUT FURTHER SINTERING AIDS. FIVE DIFFERENT COMPOSITIONS WITH 0, 5, 10, 15, AND 20 VOL.% SICP RESP. HAVE BEEN INVESTIGATED AND TRIBOLOGICAL PROPERTIES WERE CHARACTERIZED. INCREASING AMOUNT OF SICP AS RIGID PARTICLES IN THE FINE GRAINED MATRIX COMPLICATE THE DENSIFICATION PROCESS. WITH THE APPLICATION OF 50 BAR AR PRESSURE DURING THE FINAL SINTERING STEP AT A TEMPERATURE OF 1700 DEGREE C THE DENSITY OF THE SAMPLES COULD BE INCREASED BY 3-5%. INVESTIGATION OF THE TRIBOLOGICAL PROPERTIES AGAINST STEEL AS A COUNTERBODY UNDER UNLUBRICATED OSCILLATING SLIDING CONDITIONS SHOWED A HIGH COEFFICIENT OF FRICTION AND AN INCREASING WEAR RATE UP TO A SICP CONTENT OF 10 VOL. % . AT 15 AND 20 VOL. % SICP RESP. BOTH THE COEFFICIENT OF FRICTION AND THE COEFFICIENT OF WEAR DROP DOWN.
With respect to their excellent material properties ceramics are of interest as candidate materials for tribological applications. The friction and wear behaviour of ceramics is often superior to that of metallic materials. Furthermore, an essential improvement of tribological performance will be possible by tailoring of ceramics in the process of powder preparation and sintering technique. Silicon Carbide (SiC) shows interesting friction and wear behaviour at room temperature, even under unlubricated running conditions but is very sensitive against effects of environmental humidity and shows high friction and high wear in the absence of water vapour. The tribological performance of SiC can be improved considerably by adding substantial amounts of TiC and TiB2 to the microstructure thus creating ceramic particulate composite materials.
Various composites in the quasi ternary system SiC-TiC-TiB2 were prepared by a ceramic manufacturing process including sintering temperatures up to 2180 °C. Comparative tribo tests were performed under unlubricated oscillating sliding motion in dry, normal, and moist air and under water lubrication with SiC balls and Al2O3 balls as counter bodies. The friction is affected by the relative humidity (RH) but barely at all by the composition of the composites. The wear resistance of the composites was found to be improved considerably by addition of TiB2 in the range from 20 to 60 %. The highest wear resistance of the system wear was found when Al2O3 was used as counter body material.
The friction and wear behaviour of SiC, Si3N4 and SiC/Si3N4 composite ceramics were investigated with oscillating sliding (gross slip fretting) at room temperature. The influence of counter body material and the humidity of the surrounding air was studied with a ball-on-disc configuration with different ball materials (1000Cr6, Al2O3 SiC and Si3N4). The effect of RH on friction is marginal with exception of SiC (low friction) as counter body material. The wear behaviour, however, is strongly affected by humidity, showing inverse trends for different counter body materials. Consequently, the wear behaviour of a tribo couple can be improved by selecting an adequate mating material. The results reveal the necessity to control RH in tribological tests. For estimation of the performance of tribo couples under varying environmental conditions, a variation of RH is required. In tribo couples with single phase SiC, either as ball or disc, the tribological behaviour of the system is dominated by SiC. The friction behaviour of the composite material is in between the behaviour of the two single phase materials, Si3N4 and SiC, whereas the wear behaviour is very similar to that of single phase Si3N4.