Hardening by cooling rate control and post-firing heat treatment in Pd-Ag-Sn alloy for bonding porcelain

• Published in: Dental Materials Journal Vol. 35; no. 2; pp. 309 - 315
• Main Authors: YU, Young-Jun, SEOL, Hyo-Joung, CHO, Mi-Hyang, KIM, Hyung-Il, KWON, Yong Hoon
• Format: Journal Article
• Language: English
• Published: Japan The Japanese Society for Dental Materials and Devices 2016; Japanese Society for Dental Materials and Devices
• Subjects: Alloys; Cooling rate; Cooling rate control; Dental Bonding; Dental materials; Dental Porcelain; Dentistry; Firing; Furnaces; Gold Alloys; Hardening; Heat treatment; Hot Temperature; Materials Testing; Metal Ceramic Alloys; Palladium base alloys; Pd-Ag-Sn alloy for bonding porcelain; Porcelain; Post-firing heat treatment; Precipitation hardening; Simulated porcelain firing
• ISSN: 0287-4547; 1881-1361
• DOI: 10.4012/dmj.2015-189

The aim of this study was to determine the hardening effect by controlling the cooling rate during the porcelain firing process and performing an additional post-firing heat treatment in a Pd-Ag-Sn alloy. The most effective cooling rate for alloy hardening was determined by cooling the specimens at various cooling rates after oxidation treatment. A subsequent porcelain firing simulation followed by cooling at the selected cooling rate was performed. A post-firing heat treatment was then done at 600°C in a porcelain furnace. The hardening mechanism was characterized by a hardness test, X-ray diffraction, field emission scanning electron microscopy and energy dispersive X-ray spectroscopy. Alloy softening occurred during the porcelain firing process followed by cooling at a controlled cooling rate. A post-firing heat treatment allowed apparent precipitation hardening. It is advisable to perform a postfiring heat treatment at 600°C in a porcelain furnace by annealing metal substructure after porcelain fusing.