ISSN:
1551-2916
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Unlubricated pin-on-disk wear tests of Si3N4 against tool steel and gray cast iron were performed at 5 N of normal load, 0.5 m/s of sliding speed, and environmental temperature in the range 22°-600°C. The friction coefficient of Si3N4 sliding against tool steel and gray cast iron had maximum values of 0.88-0.98 for tests at 100°C. The friction coefficient of Si3N4 sliding against gray cast iron couples had minimum values of 0.48-0.57 at 400°C. Because of the increased third-body protection, the wear coefficient of the Si3N4 pins of the Si3N4/gray cast iron couples decreased by 1 order of magnitude from 1.6 10-5 mm3/(Nm) at room temperature to 1.3 10-6 mm3/(Nm) at 600°C. Fe2O3 and Fe3O4 resulting from tribooxidation of the metallic disks were the main constituents of the wear debris and adherent tribolayers. Activation energy values (6.3-13.7 kJ/mol) were comparable to those of oxidation wear of steel (7.3-11.8 kJ/mol) but were much lower than the activation energy for oxidation of iron alloys in static conditions. Calculations of the activation energy of the oxidation wear corroborate the morphological observations of a sacrificial action of the metallic surface protecting the ceramic material.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1151-2916.1999.tb01859.x
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