Members of the SPP group are involved in the broad area of “Processing-Structure-Property correlation” through the understanding of micro-mechanisms that governs the fundamental mechanical response of materials. Our studies are mostly experimental in nature, however, we always try to complement our experimental results with various simulation-based approaches (Density functional theory, Artificial neural network, etc.).
The objective of the study is to observe microstructure and texture evolution in as-cast and thermo-mechanically processed (rolled, forged, and extruded) two-phase Ti-6Al-4V alloys. For that, reconstruction of β-phase from room temperature α-phase was carried out to observe prior β grain morphology and texture. Furthermore, grain boundary α and elemental distribution effect were considered for microstructure and texture formation. In addition, crystallography of the α/β- or α/α-phase interface was noticed for the as-cast and thermo-mechanically processed alloys.
Al alloys have a heavy amount of usage in the aerospace and automotive industry. But the precipitate hardened Al alloys have a very limited high-temperature performance. Due to precipitate coarsening the mechanical properties of the alloys degrades drastically. In our study, we try to engineer the interfacial property of the precipitates in order to stabilize them at high temperatures by the means of adding a trace amount of alloying elements. Both cast and wrought Al alloys are studied in greater detail for the development of new alloy systems. State-of-the-art simulation techniques and diffusion-based studies are also done to support the experimental works.
Glass-ceramics is a unique type of material that contains randomly oriented crystals in the glass matrix. Mica glass-ceramics shows good machinability and can be made in complex shapes like metals. These materials are used in Aerospace/space applications. In our study, Microstructure development and mechanical properties of Mica machinable glass-ceramics are observed by varying processing parameters like temperature, heating rate, composition, etc. using different characterization techniques like XRD, SEM, TEM, EBSD, and fracture test.
During plastic deformation, a strong inhomogeneity occurs in metals and alloys by virtue of thermomechanical instability. Therefore, a strong localization of strain is observed due to inherent crystal anisotropy of polycrystalline materials and geometrical restrictions like grain and phase boundaries. This localization of plastic strain results in the formation of shear bands in materials and most often leads to a catastrophic failure by intensely localized shearing. In our study, we explore the formation mechanism of the shear band and its effect on the mechanical property of different materials with different crystal structures and crystallographic properties.
Laser metal deposited stainless steel (17-4 Ar PH and 316L) and WSU 100 (a Ni-based superalloy) systems are extensively studied. To date, the effect of extensive thermal cycles in the as-deposited specimens has been studied via various methods. It includes microstructure-based characterizations (OM, SEM, quantification with EBSD and XRD, etc.) and mechanical testing (micro-hardness, etc.). In addition, the porosities were identified and analyzed with the help of X-ray micro-CT. Currently, heat treatment and high temperature-based studies are going on in these systems and will be further compared from the as-deposited ones.
Ultra-high temperature applicability has made carbon fiber reinforced silicon carbide (C-SiC) composites, a potential solution in the field of aerospace. C-SiC composite is a thermo-structural material that has excellent thermal shock resistance, erosion, and oxidation resistance properties. Because of its high fracture toughness and damage tolerability, it is considered an appropriate candidate for structural applications.3D nonwoven needle-punched Carbon fiber reinforced Silicon Carbide (C-SiC) composites were synthesized by the liquid silicon infiltration (LSI) method. The microstructure, mechanical, chemical, ablation (by plasma arc jet testing), and thermal properties are being investigated in our study.
