@article{oai:nagasaki-u.repo.nii.ac.jp:00016614,
 author = {Shiraishi, Takanobu and Takuma, Yasuko and Fujita, Takeshi and Miura, Eri and Hisatsune, Kunihiro},
 issue = {11},
 journal = {Journal of Materials Science},
 month = {Jun},
 note = {Nine experimental Pd-free Ag-Au-Pt-Cu dental alloys containing 10 at.% Pt and 10-35 at.% Au were prepared and their optical properties and microstructures were investigated by means of spectrophotometric colorimetry, optical microscopy, and electron probe microanalysis. All the alloys were annealed at 850 °C and mirror-polished to observe their reflectance curves in the visible spectrum and three-dimensional color coordinates. All the alloys were composed of a major phase of Ag-Au-rich matrix and a minor and almost colorless Pt-Cu-rich phase. It was found that the color of the alloys was substantially controlled by the Ag-Au-rich matrix and that with increasing Au/Ag atomic ratio from 0.130 to 0.996, the yellow-blue chromaticity index b * increased from 8.0 to 14.4, giving a pale yellow color. This systematic increase in yellowness was caused by a continuous shift of the absorption edge of reflectance curve toward longer wavelengths with increasing Au/Ag atomic ratio., Journal of Materials Science, 44(11), pp.2796-2804; 2009},
 pages = {2796--2804},
 title = {Optical properties and microstructures of Pd-free Ag?Au?Pt?Cu dental alloys},
 volume = {44},
 year = {2009}
}