Ultrasonic complex vibration welding of same and different metal specimens and structures of the welded area are studied using several complex vibration welding systems, scanning and transmission electron microscopes (SEM and TEM). Ultrasonic welding can weld various metal directly using vibration and static clamping pressure. The welding area is limited very narrow layer and can weld different...

Improved product quality and production methods, and decreased production costs are important objectives of industries. Welding processes are part of this goal. There are many studies about monitoring and controlling welding process. This work presents a non-intrusive on-line monitoriment system and some algorithms capable of detecting GTAW weld defects. Some experiments were made to simulate w...

Joining of fixed appliance components has several applications in orthodontics. Joining attachments to archwires allows the clinician to transfer the point of force application to a location that is more advantageous from a biomechanical standpoint. Although several methods of joining attachments have been proposed, resistance spot welding and soldering have been the most commonly used procedur...

Objective: The welding process involves metal ions capable of causing cell lysis. In view of this fact, the aim of this study was to test the hypothesis that cytotoxicity is present in different types of alloys (CrNi, TMA, NiTi) commonly used in orthodontic practice when these alloys are subjected to electric spot welding. Methods: Three types of alloys were evaluated in this study. Thirty-six ...

The numerical simulation of the crack welding process is reported in this paper. The thermo-electro-structural coupled-field finite element analysis is adopted to investigate the welding process of crack surfaces. In the simulation, the pressure-dependent and temperature-dependent electrical contact conditions are considered. From the results, the crack surfaces can melt and weld together under...

D. Dobrota, Engineering Faculty, University “Constantin Brâncuşi” of Târgu-Jiu, Romania, Gh. Amza, Engineering and Tehnological Systems Management Faculty, Polytehnic University of Bucharest, Romania, Research presented in the paper refers to the structural analysis of materials that are thermally infl uenced for loading by welding of pieces in the classical variant of manual coated electric ar...

• Chipping, sledging and hammering on metal, stone or concrete • Use of manual, pneumatic and power impact tools • Caulking, brushing and grinding • Drilling, scaling and scraping soldering and casting hot metals • Handling acids, caustics and creosoted materials • Gas welding, cutting and brazing • Drilling overhead • In environments of excessive dust • Electric arc welding and cutting, and ot...

Urinary fluoride concentrations have been measured in electric arc welders using basic electrodes. The fluoride concentration and the total welding fume concentration in air showed a linear relation with postshift urinary fluoride concentration. The measured concentrations were below internationally recommended postshift urinary fluoride concentrations believed to cause fluorosis. Biological mo...