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.