Preparation and Characterization of High-Copper Restorative Dental Alloys Corrected
A series of restorative dental alloys related to the ternary system Ag-Sn-Cu were prepared using high purity 99.99% elemental constituents. The effect of increasing the copper concentration on the micro-structural and mechanical properties of conventional dental amalgam alloy was investigated. Copper content was varied in the range of 10-30wt% and that of silver in the range of 40-60wt%, while tin percentage was kept constant between 28-30wt%. Selected desired compositions were weighed, melted, and homogenized for 1h in fused-alumina crucible using wire-resistance tube furnace at 1100oC under an inert atmosphere of argon gas. Two types of alloys were prepared, the first one was by quenching in water the alloy melt from a peak temperature of 725oC, while the second type was by slow furnace-cooling of the melt down to the room temperature. Annealing of the alloys at 350- 400oC for 24 hrs was also conducted to enhance the growth of the γ-phase. The resultant alloys were then cooled to room temperature (R.T) and milled mechanically to obtain a powder having particles sizes in the range between 30-80μm. The resultant powdered alloys was then stress-relieved at 100oC for 1h. XRD analysis, optical microscopy, micro hardness, and compression strength tests were all used for the characterization and properties determination at different Cu-concentrations for the as-prepared and amalgamated alloys in addition to the powders.. The obtained relative values for the above-mentioned properties were closely related to those listed in the literatures and lies between those of mechanically-milled and those of spherical particles. Also the γ2 – phase was disappeared at high copper content of > 20wt%.
Maher Soueidan, Mohamad Roumié and Pierre Masri
Z. S. A. Al Sarraj and R. I. Atiyah, "Preparation and Characterization of High-Copper Restorative Dental Alloys Corrected", Advanced Materials Research, Vol. 324, pp. 69-72, 2011