Arc Characteristics and Weld Bead Microstructure of Ti-6Al-4V Titanium Alloy in Ultra-high Frequency Pulse Gas Tungsten Arc Welding (UHFP-GTAW) Process

Authors

  • Wei LI Beijing Institute of Petro-chemical Technology
  • Gaochong LV Beijing Institute of Petro-chemical Technology
  • Qiang WANG China Aerospace Science and Industry Group Second Research Institute
  • Songtao HUANG Beijing Institute of Petro-chemical Technology

DOI:

https://doi.org/10.5755/j01.ms.26.4.22329

Keywords:

Ti-6Al-4V, ultra-high frequency pulse GTAW, arc behavior, grain refinement, basket-weave structure

Abstract

To resolve the problem of grain coarsening occurring in the fusion zone and the heat-affected zone during conventional gas tungsten arc welding(C-GTAW) welded titanium alloy, which severely restricts the improvement of weld mechanical properties, welding experiments on Ti-6Al-4V titanium alloy by adopting ultra-high frequency pulse gas tungsten arc welding (UHFP-GTAW) technique were carried out to study arc characteristics and weld bead microstructure. Combined with image processing technique, arc shapes during welding process were observed by high-speed camera. Meanwhile the average arc pressure under various welding parameters were obtained by adopting pressure measuring equipment with high-precision. In addition, the metallographic samples of the weld cross section were prepared for observing weld bead geometry and microstructure of the fusion zone. The experimental results show that, compared with C-GTAW, UHFP-GTAW process provides larger arc energy density and higher proportion of arc core region to the whole arc area. Moreover, UHFP-GTAW process has the obviously effect on grain refinement, which can decrease the grain size of the fusion zone. The results also revealed that a significant increase of arc pressure while increasing pulse frequency of UHFP-GTAW, which could improve the depth-to-width ratio of weld beads.

Author Biographies

Wei LI, Beijing Institute of Petro-chemical Technology

Department of Electrical Engineering

Gaochong LV, Beijing Institute of Petro-chemical Technology

Department of Electrical Engineering

Songtao HUANG, Beijing Institute of Petro-chemical Technology

College of Mechanical and Electrical Engineering

Downloads

Published

2020-09-01

Issue

Section

METALS, ALLOYS, COATINGS