Establishing relationship between fusion zone hardness and grain size of gas tungsten constricted arc welded thin sheets of titanium alloy

Abstract

Ti-6Al-4V alloys are perfectly suited for fan compressor blade material in advanced aero engine components due to outstanding resistance to corrosion and specific strength was high in both room temperature and elevated temperature. For autogeneous welding of thin sheets of Ti-6Al-4V alloy, the gas tungsten constricted arc welding (GTCAW) was established to be beneficial than the gas tungsten arc welding process. The performance of welded joints depends on the fusion zone grain size (FZG) and fusion zone hardness (FZH), which need to be suitably optimized and controlled to attain advantageous mechanical characteristics of the joint. Hence, in this research study, efforts were taken to develop empirical relationships for predicting the FZH and FZG incorporating very important GTCAW parameters. Parameter optimization was performed using response surface methodology. Additionally, the influence of GTCAW parameters on FZG and FZH was analyzed. From the results, it is inferred that the inter-pulse frequency has better influence on FZG and FZH compared to other parameters.

Productivity improvement in butt joining of thick stainless steel plates through the usage of activated TIG welding

“…Coarse grains are associated with lower hardness due to less grain boundaries within the fixed indentation area. A similar observation in gas tungsten constricted arc welding was also reported by Vaithiyanathan et al (2020) [26].…”

Effect of Heat Input on Evolution of Microstructure and Tensile Properties of Gas Tungsten Constricted Arc (GTCA) Welded Inconel 718 Alloy Sheets

“…Leary et al [14] practised GTCAW process for joining of Ti6Al4V alloy without the need of trailing gas shield and concluded that magnetic arc constriction technique extends better microstructural evolution of weld relative to normal GTAW as a result of lower heat input. Vaithiyanathan et al [15] stated that pulsing current at high frequency eliminated the evolution of widmanstatten structure in weld metal leading to superior strength in GTCA welded Ti6Al4V sheets relative to GTAW process. InterPulse current frequency extends significant influence on grain size and hardness of fusion zone in GTCA welded Ti6Al4V joints [16].…”

“…The published literature mainly pertains to gas tungsten arc welding (GTAW) [20][21][22], electron beam welding (EBW) [23][24][25] and laser beam welding (LBW) [26][27][28] of Inconel 718 alloy. The investigations on GTCA welding process are limited to titanium alloys [12][13][14][15] and steel [16,17]. In the previous investigation [18], GTCAW process was successfully used to join 2-mm-thick Inconel 718 alloy sheets.…”