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Erosion Wear Properties of Tetragonal ZrO 2 (Y 2 O 3 )‐Toughened Al 2 O 3 Composites
Author(s) -
Kamiya Hidehiro,
Sakakibara Masato,
Sakurai Yukio,
Jimbo Genji,
Wada Shigetaka
Publication year - 1994
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1994.tb05346.x
Subject(s) - materials science , composite material , ceramic , tetragonal crystal system , cubic zirconia , composite number , volume fraction , wear resistance , particle (ecology) , particle size , phase (matter) , analytical chemistry (journal) , chemical engineering , chemistry , oceanography , organic chemistry , geology , chromatography , engineering
Erosion wear properties of tetragonal zirconia ( t ‐ZrO 2 with 3 mol% Y 2 O 3 )/Al 2 O 3 composites with different volume fractions of t ‐ZrO 2 in the rang of O to 100 vol% (including Al 2 O 3 or t ‐ZrO 2 ceramics), were measured by a collision test between Al 2 O 3 or SiC particles accelerated in an air stream (240 m/s) and a stationary composite or ceramics target. In the case of Al 2 O 3 erodent particles, the wear rate of composites decreased to one‐tenth of the wear rate of Al 2 O 3 or t ‐ZrO 2 ceramics. The optimum volume fraction of the addi‐tive phase for increased wear resistance was in the range of 7 to 22 vol% of t‐ZrO 2 . However, the wear resistance of all composites in collision with SiC particles deteriorated. The maximum wear rate appeared at about 40 vol% of t‐ZrO 2 , and reached two times that of the Al 2 O 3 or t‐ZrO 2 ceramics. The mean fracture load of the SiC erodent particle in a diametral compression test under quasi‐static loading was 2.3 times the value of the Al 2 O 3 particle, which broke after collision with the target. Therefore, the mean impact force produced by Al 2 O 3 particles striking the target was much lower than that from SiC particles. Because the impact force acting from the Al 2 O 3 particles did not reach the threshold force required for lateral crack propagation in the composites, the principal damage mechanism, the wear resistance of composites increased. However, the impact force from SiC particles was greater than the threshold force, and lateral or other damaging cracking was promoted at the wear surface of the composite materials. This discussion is in agreement with the analysis by the lateral crack model and the results for the median crack length of each ceramic measured by Vickers indentation tests with different loads. The slope of the logarithm of median crack length as a function of the logarithm of Vickers indent load was larger than the value of 2/3 obtained theoretically.