Effect of cooling rate during oxidation treatment on the hardness change by post firing heat treatment of a Pd-Cu-Ga-Zn alloy after simulated porcelain firing
10.14815/kjdm.2018.45.1.21
- Author:
Min Jung KIM
1
;
Hye Jeong SHIN
;
Yong Hoon KWON
;
Hyung Il KIM
;
Hyo Joung SEOL
Author Information
1. Department of Dental materials and BK21 PLUS Project, School of Dentistry, Pusan National University, 49 Busandaehak-ro, Yangsan-si, Gyeongsangnam-do, Korea. seol222@pusan.ac.kr
- Publication Type:Original Article
- Keywords:
Pd-Cu-Ga-Zn alloy;
firing simulation;
cooling rate;
post-firing heat treatment
- MeSH:
Alloys;
Dental Porcelain;
Fires;
Hardness;
Hot Temperature
- From:
Korean Journal of Dental Materials
2018;45(1):21-34
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
Effect of cooling rate during oxidation treatment on the hardness change by post firing heat treatment of a Pd-Cu-Ga-Zn alloy after simulated porcelain firing was investigated and the following results were obtained. In the firing simulated specimens after quenching during the oxidation treatment, the hardness did not increase by post-firing heat treatment. However, in the firing simulated specimens after slow cooling during the oxidation treatment, post-firing heat treatment for 25 minutes was effective in increasing the hardness (p < 0.05). In the firing simulated specimens after quenching during the oxidation treatment, the significant decrease in hardness during the post-firing heat treatment was attributed to the coarsening of fine precipitates formed in the matrix and plate-like precipitates. In the firing simulated specimens after slow cooling during the oxidation treatment, the increase in hardness during the post-firing heat treatment for 25 minutes was due to precipitation hardening. From these results, it was found that the cooling rate during the oxidation treatment affected the change of hardness by the post-firing heat treatment after the simulated firing. From these results, post-firing heat treatment increased the hardness of the Pd-Cu-Ga-Zn alloy only when the cooling rate during the oxidation treatment was slow.
