Research Projects

Over the past few decades, intermetallic titanium aluminide (TiAl) have emerged as promising candidate material for weight-sensitive applications, particularly in aerospace components such as low-pressure turbine(LPT) blades. Owing to their low density (~4 g/cm³) and a combination of high-temperature strength, oxidation resistance, and specific strength, TiAl alloys offer properties that are comparable to conventional Ni-based superalloys [1].Titanium aluminide (TiAl) alloys fabricated via ingot metallurgy(IM) often suffer from chemical inhomogeneity arising from elemental segregation, primarily due to the significant difference in melting points between titanium and aluminum [2]. Similarly, metal injection molding(MIM) presents challenges such as restrictions on component size and contamination issues, particularly increased carbon and oxygen pickup during the thermal de-binding stage [3]. In recent years, electron beam melting(EBM) has garnered interest for TiAl processing, as it effectively mitigates some of the drawbacks associated with conventional techniques. However, EBM demands high-cost infrastructure, stringent control over processing parameters, and is not well-suited for large-scale production scenarios [4]. Furthermore, many of these methods necessitate extensive post-processing, contributing to elevated manufacturing costs. In this context, powder metallurgy (PM) emerges as a promising alternative, offering superior microstructural control, reduced material waste, shorter processing time, and minimal machining requirements all at comparatively lower production costs [5]. Though, some of the TiAl components are made via the powder metallurgy route via Hot-isostatic pressing(HIP) or Spark plasma sintering(SPS). These components still appear to have issues like the presence of residual porosity and prior particle boundaries (PPB), swelling due to the reaction between high reactivity between Ti and Al powders, and oxygen pickup which is known to have detrimental effects such as reduction of fracture toughness and room temperature ductility[5,6]. To overcome the problems mentioned above, it is necessary to implement a new method of manufacturing, such as Direct Powder Forging(DPF) for TiAl. Literature on DPF technique has predominantly been used to reduce porosity, PPBs, and elongated grains in Ni based superalloys. However, no attempt has been made to extend the direct powder forging method for producing TiAl. Hence, the proposed project aims to develop a Ti-48Al-2Nb-2Cr alloy by direct powder forging and evaluate high-temperature creep properties. 1.B.P.Bewlay,Materials at High Temperatures,33,549-559(2016) 2.V.Güther,Berg Huettenmaenn Monatsh, 155, 325–329(2010) 3.C.Zhang,The International Journal of Advanced Manufacturing Technology(2023) 4.A.Emiralioğlu,Journal of Materials Science,57,4441–4466(2022) 5.J.A.N. Da Silva,Materials Science and Technology,39,42-49 (2023) 6.H.Z. Niu, Materials Science and Engineering: A,737,151-157(2018)