Introduction: In dental laboratory prosthetics, joining methods are indispensable since they are employed in all its fields: orthodontics, fixed and removable dental prosthetics as well as in surgery. Joining methods used in laboratory dental prosthetics are the following: soldering, resistance spot welding, plasma welding, laser welding, and arc welding in the protection of the inert gas with the non-consumable tungsten electrode (TIG welding). In practice, the terms soldering and welding tend to be confused many a time, despite a great difference exists between the two. Purpose: The purpose of this diploma thesis is to study joining methods and examine, based on examples of joining of cylindrical trial objects made of the Cr-Co alloy, the advantages and disadvantages of the joining methods of soldering, laser welding, and TIG welding, as well as to examine microstructure, Vickers hardness and flexural strength of joints. Methods: The descriptive method was used to review the literature concerning joining methods in this diploma thesis. The results part of the thesis focused on making trial objects which were laser welded, soldered and TIG welded. Afterwards, we used the trial objects in the bend test, analysed their microstructure under a microscope and did the Vickers hardness test. Results: The results part introduces hardness measurement values, flexural strength and micrographs of joints of individual samples joined using various methods that we created within the experimental part of the thesis. Discussion and conclusion: The bend test unveiled that the soldered trial objects exhibit the highest flexural strength, they are followed by the laser-welded ones, whilst the TIG welded trial objects display the lowest flexural strength. When inspecting the microstructure of joints, anomalies were observed on micrographs with all three joining methods. Based on the analysis of the carried out tests, it can be deduced that the most appropriate joining method is soldering, however, it is believed that, with some optimisation of the parameters used, the results of the other two techniques can be ameliorated. The obtained results and the parameters used are a good starting point for future research in the field.
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