Lyra e Silva João Paulo, Fernandes Neto Alfredo Júlio, Raposo Luís Henrique Araújo, Novais Veridiana Resende, de Araujo Cleudmar Amaral, Cavalcante Luisa de Andrade Lima, Simamoto Júnior Paulo Cezar
Department of Occlusion, Fixed Prosthodontics and Dental Materials, Dental School, UFU - Universidade Federal de Uberlândia, Uberlândia, MG, Brazil.
Braz Dent J. 2012;23(6):686-91. doi: 10.1590/s0103-64402012000600010.
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 (p<0.001), with higher flexural strength for the control group (p<0.05). No significant differences was observed among the plasma welded groups (p>0.05). The NCB group showed the lowest flexural strength, although it was statistically similar to the PL 14 group (p>0.05). 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.
本研究的目的是评估不同等离子弧焊参数对钛合金梁（Ti-6Al-4V）抗弯强度的影响。制备了40根Ti-6Al-4V和10根NiCr合金梁试件（长40 mm，直径3.18 mm），并分为5组（n = 10）。对照组的钛合金梁未进行切割或焊接。PL10组、PL12组和PL14组分别包含在3 A电流下切割并焊接10、12或14毫秒的钛梁。NCB组由使用传统焊炬钎焊焊接的NiCr合金梁组成。之后，对梁进行三点弯曲试验，并对获得的值进行分析以评估抗弯强度（MPa）。采用单因素方差分析和Tukey's HSD检验在0.05置信水平下进行统计分析。在评估组之间验证了显著差异（p < 0.001），对照组的抗弯强度更高（p < 0.05）。在等离子焊接组之间未观察到显著差异（p > 0.05）。NCB组的抗弯强度最低，尽管在统计学上与PL 14组相似（p > 0.05）。等离子焊接组之间的焊缝熔深没有显著差异（p = 0.05）。随机选择三个代表性试件在扫描电子显微镜下进行评估。通过能量色散X射线光谱分析焊接区域的成分。本研究提供了一组初步参数，支持在钛合金牙科支架制造过程中使用等离子焊接。
