Microstructure and segregation behavior of palladium in silver-copper-palladium alloys.
It has been reported that the addition of palladium can modify the microstructure and improve the properties of Ag-Cu eutectic alloy as well as admixed Cu-rich amalgam. The purpose of this work was to study the microstructure and segregation behavior of palladium in a series of Ag-Cu-Pd alloys. All microstructural and microchemical results consistently indicated a strong tendency for palladium to form the ordered Cu3Pd superlattice in the copper-rich phase of the present ternary alloys. Transmission electron microscopic examination indicated that, in addition to the large Cu-rich particles, numerous small (typically tens of nanometers) Cu-rich particles were distributed in the Ag-rich phase. In the alloys containing 10 and 15 wt% Pd, the Cu3Pd superlattice had an L1(2)-type crystal structure. In the alloy containing 20 wt% Pd, the Cu3Pd had a periodic (regular) APB structure. The solubility of palladium in the Cu-rich phase was always much larger than that in the Ag-rich phase. The ratio of the palladium concentration in the copper-rich phase to that in the silver-rich phase decreased with the overall palladium content.
Chen
K I
KI
Department of Materials Science and Engineering, National Cheng-Kung University, Tainan, Taiwan, ROC.
Lin
J H
JH
Ju
C P
CP
D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003300:Copper / Q000737:chemistry; D018360:Crystallography, X-Ray; D003722:Dental Alloys / Q000737:chemistry*; D004577:Electron Probe Microanalysis; D008832:Microchemistry; D008854:Microscopy, Electron; D010165:Palladium / Q000737:chemistry*; D012834:Silver / Q000737:chemistry; D012995:Solubility
D003722:Dental Alloys; D012834:Silver; D010165:Palladium; D003300:Copper