BACKGROUND This study aimed to determine the effect of hardness change according to penetration depth in the laser fusing zone and observed the correlation of the microstructure as an Nd:YAG laser was irradiated to Ni-Cr alloy for dental use by setting the spot diameter size with respect to defocusing distances. In all groups, the hardness depth profiles in the laser fusing zone and heat-affect...

This manuscript is published as part of the proceedings of the NIH Technology Assessment Conference on Effects and Sideeffects of Dental Restorative Materials, August 26-28,1991, National Institutes of Health, Bethesda, Maryland, and did not undergo the customary journal peer-review process. I t is estimated that 96% of adults in the United States between the ages of 18 and 65 have one or more ...

Nanoparticle alloys of platinum (Pt) and another metal are desirable for catalytic applications to decrease the loading of the precious metal and alter the physiochemical structure of these materials to enhance their catalytic properties. This study explores the potential of producing gold and platinum nanoparticle alloys using a microplasma reduction technique. In this process, metal salt prec...

early a million years ago, mankind’s technological march through time beN gan after fire was mastered. Metalworking, which evolved into metallurgy, is the oldest and most successful technology. It spans at least 12,000 years (Figure 1). Soldering, a key metal joining technology, was probably developed about 7,000 years ago when lower melting, naturally occurring metal alloys were placed in the ...

In the restoration of lost or misaligned dental pieces, dissimilar alloys are frequently used in oral cavity, which form galvanic couples that corrode due to effect saliva and dentin fluids. this work, microstructure ten non-precious was analyzed by optical microscopy, open-circuit corrosion potential each alloy measured against a saturated calomel electrode, they were subjected accelerated pro...

Precious metal alloys enables new possibilities to tailor materials for specific optical functions. Here we present a systematic study of the effects of a nanoscale alloying on the permittivity of Au-Ag-Cu metals at 38 different atomic mixing ratios. The permittivity was measured and analyzed numerically by applying the Drude model. X-ray diffraction (XRD) revealed the face centered cubic latti...

The performance of laser welding of Ti and two dental precious alloys (Ag-Pd-Au, Au-Pt-Ag) was investigated by mechanical testing and microscopic observation, using butt joint as design. The laser irradiation was done using a commercial Nd:YAG dental laser-welding device in a single pulse mode with output currents 150, 200, 250, 300A, spot diameters 0.6, 0.9, 1.2mm, and pulse duration 10ms. The...