Development of Ag-Pd-Au-Cu Alloy for Multiple Dental Applications

Part 1 Effects of Pd and Cu Contents, and Addition of Ga or Sn on Physical Properties and Bond with Ultra-low Fusing Ceramic

抄録

Ag-Pd-Au-Cu quaternary alloys consisting of 30-50% Ag, 20-40% Pd, 10-20% Cu and 20% Au (mother alloys) were prepared. Then 5% Sn or 5% Ga was added to the mother alloy compositions, and another two alloy systems (Sn-added alloys and Ga-added alloys) were also prepared. The bond between the prepared alloys and an ultra-low fusing ceramic as well as their physical properties such as the solidus point, liquidus point and the coefficient of thermal expansion were evaluated. The solidus point and liquidus point of the prepared alloys ranged from 802°C to 1142°C and from 931°C to 1223°C, respectively. The coefficient of thermal expansion ranged from 14.6 to 17.1×10^-6/°C for the Sn- and Ga-added alloys. In most cases, the Pd and Cu contents significantly influenced the solidus point, liquidus point and coefficient of thermal expansion. All Sn- and Ga-added alloys showed high area fractions of retained ceramic (92.1-100%), while the mother alloy showed relatively low area fractions (82.3%) with a high standard deviation (20.5%). Based on the evaluated properties, six Sn-added alloys and four Gaadded alloys among the prepared alloys were suitable for the application of the tested ultra-low fusing ceramic.