| Advanced ceramics are of increasing interest for wear components in liquid media in the chemical industry. Aim of this study was to meet the need for development of tribological parts in pumps. At room temperature tribological properties of different sliding pairs of silicon carbide and alumina-based ceramics were tested using a laboratory tribometer in the ring-on-plate geometry under reciprocating sliding linear contact in different media, such as distilled water, aggressive media and air. Worn surfaces of sliding pairs were characterized by scanning electron microscopy (SEM). Chemical compositons on the worn surfaces were analyzed by energy dispersion X-ray analysis (EDAX), and profiles and suface roughness of the worn surfaces were measured by stylus profilmetry.In the present paper tribological studies of sliding pairs, SiC/SiC, Al2O3/Al2O3 and Al2O3/ZTA, which were composed of some commercially available ceramics, such as sintered silicon carbide (Ekasic F), monolithic alumina (F99.7) and multi-phase alumina ZTA ( zirconia toughened alumina, SN80), were carried out in distilled water, 1mol/L caustic soda (NaOH), Imol/L hydrochloride solution (HC1) and air at 50% relative humidity. Surface treatment using a CO2 laser was conducted on a commercially available alumina A124 with less than 5 vol% open porosity, on which ceramic powder was precoated, and two different laser modified structures, A124ZY and A124ZYS, were prepared, then tribological properties of them were measured using Al2O3 (F99.7) as counterbodies. ZTAL structure was made by laser remelte ZTA, and tribological properties of sliding pairs, Al2O3/ZTAL and SiC/A124ZY, were also measured. Friction coefficient and amount of linear wear (sum of ring and plate) were continuously measured and recorded during each test, and amount of linear wear of ring and plate was separately determined from surface profiles with a profilmetry after the tests. The reported friction coefficients and amounts of linear wear were average values of at least two individual tests. Influences of surface roughness, media, normal load, slinding frquencey and sliding distance on friction coefficients and amounts of linear wear of different sliding pairs were mainly studied. After the tribological properties of the different sliding pairs in different media were compared, tribological mechanisms of the sliding pairs were analyzed, and some factors, which have an influence on the tribological properties of the studied ceramics, were further discussed.Tribological reactions would affect tribological properties of ceramics. Thermaldynamic properites of Al2O3, ZrO2 and SiO2 in water were depicted through potential-pH diagrams, and possibilities of formation of tribochemical films on tribological interaction surface of ceramics and stabilities of the films in differentsolutions at different pH values were discussed.Experimental results showed that the largest friction coefficients of the sliding pairs, A12O3/A12O3, A12O3/ZTA, SiC/SiC, A12O3/A124ZY and A12O3/A124ZYS, were smaller than 0.32, 0.17, 0.15 in distilled water, 1mol/LNaOH and 1 mol/L HC1, respectively, at nomal load of 60N, a sliding distanc of 288m, an reciprocating frequency of lOHz and a stroke of 8mm which resulted in an average sliding speed of 0.16m/s. In distilled water and 1 mol/L HC1 friction coefficients of SiC/SiC were smaller than 0.02, and 0.1 in 1 mol/L NaOH. In air at 50% relative humidity firction coefficients of the five sliding pairs tested fluctuated between 0.6-0.8. The fiction coefficients of the five sliding pairs in different media were in the succession of, respectively.in distilled water: uAl2O3> uAl2O3/Al2O3> uAl2O3/Al24ZYS>uAl2O3/Al24ZY>uSiC/SiC in 1mol/L NaOH:in air at 50% relative humidity: and the friction coefficients of the sliding pairs A12O3/A12O3, A12O3/ZTA, A12O3/A124ZY and A12O3/A124ZYS were in the order of u. Air> uH2O > u NaOH> u HCl, andu Air/ u NaOH> HH2O > u Hcl f皉 that of the sliding pair SiC/SiC. Accordingly, in thedifferent med...
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