摘要
Stress corrosion cracking (SCC) of a PZT ferroelectric ceramics in various media, such as moist at-mosphere, silicon oil, methanol, water and formamide, and its anisotropy have been investigated at constant load test using a single-edge notched tensile specimen. The results showed that SCC could occur in all media, and the threshold stress intensity factor of SCC in water and formamide, KISCC, revealed anisotropy. The KISCC for poling direction parallel to the crack plane, aISCC,Kwas greater than that perpendicular to the crack plane, bISCC,K similar to the anisotropy of fracture toughness KIC; however, the anisotropy factor of KISCC, which was abISCCISCC/KK=1.8 (in formamide) and 2.1 (in water), was larger than that of KIC, which is abICIC/KK=1.4. The stress-induced 90?domain switching causes the anisotropy of KIC and KISCC, besides, the resistance of SCC also has anisotropy.
Stress corrosion cracking (SCC) of a PZT ferroelectric ceramics in various media, such as moist atmosphere, silicon oil, methanol, water and formamide, and its anisotropy have been investigated at constant load test using a single-edge notched tensile specimen. The results showed that SCC could occur in all media, and the threshold stress intensity factor of SCC in water and formamide, KISCC, revealed anisotropy. The KISCC for poling direction parallel to the crack plane, KISCC a was greater than that perpendicular to the crack plane, KISCC b similar to the anisotropy of fracture toughness KIC; however, the anisotropy factor of KISCC, which was KISCC a/KISCC b =1.8 (in formamide) and 2.1 (in water), was larger than that of KIC which is KICa/KICb =1.4. The stress-induced 90° domain switching causes the anisotropy of KIC and KIC, besides, the resistance of SCC also has anisotropy.
