Effect of plasma welding parameters on the flexural strength of Ti-6Al-4V alloy

Braz Dent J. 2012;23(6):686-91. doi: 10.1590/s0103-64402012000600010.

Abstract

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.

MeSH terms

  • Alloys
  • Argon / chemistry
  • Chromium Alloys / chemistry
  • Dental Alloys / chemistry*
  • Dental Soldering / instrumentation
  • Dental Soldering / methods*
  • Humans
  • Materials Testing
  • Microscopy, Electron, Scanning
  • Plasma Gases / chemistry*
  • Pliability
  • Spectrometry, X-Ray Emission
  • Stress, Mechanical
  • Surface Properties
  • Titanium / chemistry*
  • Welding / instrumentation
  • Welding / methods

Substances

  • Alloys
  • Chromium Alloys
  • Dental Alloys
  • Plasma Gases
  • titanium alloy (TiAl6V4)
  • Argon
  • Titanium