Investigations of Elastic Properties of Laser Welded Dental Alloys

Previous investigations have shown that laser welding has a lot of advantages compared to the conventional soldering technique: The etched cross sections of laser welded alloys show only little porosities in the welded area while large shrinkholes can be seen in the cross section of soldered specimen [l]. Therefore the ultimate tensile strength of the welded specimen is significantly higher than that of the soldered one [2]. The maximal ultimate tensile strength, obtainable with optimal preparation of samples [3] and optimized laser parameters, will be about 95% of the strength of the base material [4]. Beside the ultimate tensile strength the elastic properties of dental alloys are very important, especially for those alloys being used, for example, in clamps, bars, bridgeworks or ceramic fixed prostheses. To introduce laser welding as a new joining technique in dental technology it is necessary to know how the laser welding process influences the elastic properties of dental alloys. Therefore investigations concerning the variation of the modulus of elasticity due to the laser welding process and following stress alternations have been carried out.