Lee, DY Kim, DJ Cho, KS 2024-01-21T17:31:36Z 2024-01-21T17:31:36Z 2021-09-05 1998-02 0916-1821 https://pubs.kist.re.kr/handle/201004/143261 Y2O3 and Nb2O5 co-doped tetragonal ZrO2 polycrystals (TZPs) were synthesized by hot-pressing (HPing) at temperatures in the range of 1300 to 1500 degrees C to investigate the effect of alloying on the mechanical properties of TZPs. TZPs (89.25 mol% ZrO2-5.75 mol% Y2O3-5.00 mol% Nb2O5 and 90.24 mol% ZrO2-5.31 mol% Y2O3-4.45 mol% Nb2O5), prepared by HPing at 1400 degrees C for 1 h, showed a negligible monoclinic (m-) ZrO2 content (<1%), the highest flexural strength of about 1 GPa, and the fracture toughness of above 7.5 MPa.m(1/2). Both low and high temperature (250 to 1000 degrees C) aging for up to 100 h was carried out to evaluate the phase stability. TZPs, aged at temperatures higher than 400 degrees C, suffered from strength degradation due to the extensive cavitation caused by graphite oxidation. The carbon incorporated in TZPs was identified as either an ether-type C-O or a carbonyl-type C=O. On the other hand, the specimens aged at temperatures lower than 400 degrees C maintained the phase stability and mechanical properties. English JAPAN INST METALS FRACTURE-TOUGHNESS HIGH-TEMPERATURE TETRAGONAL ZRO2 STABILITY Mechanical properties of hot-pressed TZP ceramics doped with Y2O3 and Nb2O5 Article 10.2320/matertrans1989.39.262 1 MATERIALS TRANSACTIONS JIM, v.39, no.2, pp.262 - 267 MATERIALS TRANSACTIONS JIM 39 2 262 267 scie scopus 000073121800005 2-s2.0-0031998901 Materials Science, Multidisciplinary Metallurgy & Metallurgical Engineering Materials Science Metallurgy & Metallurgical Engineering Article FRACTURE-TOUGHNESS HIGH-TEMPERATURE TETRAGONAL ZRO2 STABILITY tetragonal zirconia polycrystal (TZP) hot-pressing (HPing) aging phase stability graphite oxidation