engleski

Study of microstructure of titanium alloys laser welded joints

Titanium and its alloys are often cited in dentistry as ‘metals of the future'. The aim of this research is to determine the structure and microhardness of three laser-welded specimens of titanium-chromium-niobium alloy (Ti80Cr10Nb10) and to relate them with the use in dental prosthetics. Specimens are casted according to ISO standard and then cut in two equal parts. They were welded by Nd:YAG laser with different voltage (270 V, 300 V, 330 V) at a pulse duration of 10 ms without filler. Macro- and microstructure of all samples were analysed by light and scanning electron microscope. Macroscopically are visible high-quality welded joints without porosity and fractures. The results of the microstructural analysis indicate that substrates of all specimens contain two- phase structure, while the joints reveal more homogenic β-phase structure. Microhardness was determined in substrate, joint and heat affected zone for each sample. According to the obtained results, the relation between microhardness measurements and amount of α-phase in the microstructure of the material has been perceived which is likewise correlated with the laser beam intensity. The results demonstrate a high quality of all three welded specimens, meaning that used parameters can be practically applicable in dental medicine.

titanium alloys, casting, laser welding, microstructure

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