title: Effect of addition of palladium on properties of Ag2Hg3 (gamma 1) phase.
abstract: The effect of palladium addition on the microstructure, compressive strength, creep rate and mercury release rate of Ag2Hg3 (gamma 1) phase was evaluated. Experimental results indicated that fairly pure gamma 1 phase could be fabricated using the present trituration method. The heat treatment of gamma 1 at 90 degrees C increased porosity level, increased dimensional shrinkage, increased mercury vapour release and enhanced the formation of beta1 phase. Addition of palladium in gamma 1 slowed down the amalgamation reaction, largely suppressed the phase transition to beta1 and caused a slight shift in open circuit potential toward the anodic direction. Although the overall anodic polarization profiles did not show a significant effect of palladium, scanning electron microscopy revealed morphological differences between pure and palladium-containing gamma 1. Addition of palladium in gamma 1 also increased compressive strength, increased creep resistance, and largely reduced both mercury vapour and ion release rates. Considering overall performance, the optimal palladium content in gamma 1 seems to be in the range between 0.50 and 0.75 wt%.
authors.affiliation: Department of Materials Science and Engineering, National Cheng-Kung University, Tainan, Taiwan, ROC.
authors.forename: J H
authors.initials: JH
authors.lastname: Chern Lin
authors.forename: H C
authors.initials: HC
authors.lastname: Lee
authors.forename: C P
authors.initials: CP
authors.lastname: Ju
mesh_terms: D003723:Dental Amalgam / Q000737:chemistry*; D008628:Mercury; D008855:Microscopy, Electron, Scanning; D010165:Palladium; D011199:Potentiometry; D012464:Saliva, Artificial; D012834:Silver; D013314:Stress, Mechanical; D013718:Tensile Strength; D014961:X-Ray Diffraction
chemical_list: D012464:Saliva, Artificial; C107243:silver mercury amalgam; D012834:Silver; D010165:Palladium; D003723:Dental Amalgam; D008628:Mercury