ZrO.sub.2 based ceramic material and method of producing the same

Abstract

A ZrO.sub.2 based ceramic material having excellent mechanical strength and fracture toughness comprises a first phase of ZrO.sub.2 grains containing CeO.sub.2 as a stabilizer and having an average grain size of 5 .mu.m or less, a second phase of Al.sub.2 O.sub.3 grains having an average grain size of 2 .mu.m or less, and a third phase of elongated crystals of a complex oxide of Al, Ce, and one of Mg and Ca. At least 90 vol % of the first phase is composed of tetragonal ZrO.sub.2. An aluminum (Al) content in the ceramic material is determined such that when Al of the complex oxide is converted to Al.sub.2 O.sub.3, a total amount of Al.sub.2 O.sub.3 in the ceramic material is within a range of 0.5 to 50 vol %. A content of the third phase in the ceramic material is determined within a range of 0.5 to 5 by area %. It is preferred that fine Al.sub.2 O.sub.3 grains having an average grain size of 1 .mu.m or less of the second phase are dispersed within the ZrO.sub.2 grains at a dispersion ratio of at least 2%.

Dependencies are inferred from the claim text.