Effect of plasma welding parameters on the flexural strength of ti-6al-4v alloy

The aim of this study was to assess the effect of different plasma arc welding parameters on the flexural strength of titanium alloy beams (Ti-6Al-4V). Forty Ti-6Al-4V and 10 NiCr alloy beam specimens (40 mm long and 3.18 mm diameter) were prepared and divided into 5 groups (n=10). The titanium alloy beams for the control group were not sectioned or subjected to welding. Groups PL10, PL12, and PL14 contained titanium beams sectioned and welded at current 3 A for 10, 12 or 14 ms, respectively. Group NCB consisted of NiCr alloy beams welded using conventional torch brazing. After, the beams were subjected to a three-point bending test and the values obtained were analyzed to assess the flexural strength (MPa). Statistical analysis was carried out by one-way ANOVA and Tukey's HSD test at 0.05 confidence level. Significant difference was verified among the evaluated groups (p0.05). The weld depth penetration was not significantly different among the plasma welded groups (p=0.05). Three representative specimens were randomly selected to be evaluated under scanning electron microcopy. The composition of the welded regions was analyzed by energy dispersive X-ray spectroscopy. This study provides an initial set of parameters supporting the use of plasma welding during fabrication of titanium alloy dental frameworks. O objetivo deste estudo foi avaliar o efeito de diferentes parâmetros de solda a plasma verificando a resistência flexural de barras de liga de titânio (Ti-6Al-4V). Quarenta espécimes de Ti-6AL-4V e dez espécimes de liga de NiCr foram preparados (40 mm de altura e 3,18 mm de diâmetro) e divididos em 5 grupos (n=10). As barras de liga titânio do grupo controle não foram seccionadas e nem submetidas a processo de soldagem. Os grupos PL10, PL12 e PL14, continham barras de titânio seccionadas e soldadas com uma corrente de 3 A por períodos de 10,12 e 14 ms, respectivamente. O grupo NCB consistiu de barras de liga de NiCr soldadas pelo método de brasagem convencional. Em seguida as barras foram submetidas ao teste de flexão de três pontos e os valores obtidos foram transformados em resistência flexural (MPa). Análise estatística foi realizada usando ANOVA de fator único e o teste Tukey com o nível d