Abstract
Introduction: Microplasma welding of dental alloys, in an inert gas environment, have led to substantial improvements to the traditional joining procedures used in denture technology.
The purpose of the research was to assess the welding quality of Ni-Cr alloys used in fixed dental prosthodontics, depending on their chemical composition, structure and the selected welding parameters.
Materials and Methods: For experimental tests different Ni-Cr alloys were selected. Plates were cast conventionally using an induction melting centrifugal casting machine. They were welded bilaterally in a butt joint configuration, varying the device parameters, using a microplasma Welder. Welded specimens were analyzed macroscopically, microscopically, radiographic, metallographic and the microhardness was determined in the base metal (BM), weld metal (WM) and heat affected zone (HAZ).
Results: Even the chemical composition of all the alloys was similar, the weldability was different.
Discussion: The areas with microstr uctural changes and increased microhardness values, located in the HAZ are fragile structures, that can lead to an early degradation of the welded structure during functional loads.
Conclusion: Ni-Cr alloys with similar composition may react differently to the welding process.
