Working under Prof. Shantanu Kumar Behera, Subham Mahato expressed his desire to work for his MTech dissertation on a research topic of industrial relevance, Prof Behera, his advisor had to think for a while before scrapping the scientifically intense work he had already planned out.
Little did they know that they were going to explore something that was going to lead to more issues and interest.
The work that Subham pursued applied a subtle concept of a MgO-C system, which is a refractory system of immense importance for the steel industry. Graphite is an integral part of such refractories since it is not wetted by molten steel (like a water drop on a lotus leaf), and thus has high corrosion resistance. But it oxidises at moderate temperatures causing material loss. Lot of graphite in the refractory also accounts for more heat loss. The challenge, therefore, was to have as low carbon as possible, yet retain most of the beneficial properties of graphite. Prof Behera and Subham used a special form of reactive graphite in their laboratory, and carried their stuff to a nearby industry to manufacture their refractories. The new products, codenamed Carbex showed some nice and exciting results.
The Carbex bricks showed enhanced thermal shock resistance and oxidation resistance. The hot strength of the material almost doubled. When used in the newly installed Field Emission Scanning Electron Microscope in the department a homogeneous precipitation of some nanostructured high temperature phases (aluminium nitride, spinel etc.) was discovered, as opposed to the sporadic presence of such phases in commercial compositions. The new type of carbon the group had used caused the development of such features.
After Subham graduated, and Kuldeep Singh took the baton from him, and applied the same concept to another graphite containing system(Alumina-Silicon Carbide-Graphite) that is used in torpedo cars carrying molten iron. Kuldeep shuttled between NIT and TRL Krosaki Refractories to take the work further, and the results he produced were no less exciting.
According to Prof. Behera the produced Carbex variety exhibits military type defence mechanism to oxygen ingress at high temperatures, with layer by layer protection. The commercial refractories have civilian mechanism, which is random and uncoordinated. He is delighted by the level of progress his students have made in an area that doesn’t attract the best of his efforts and interest. But, he says it is important to keep working in areas that have immediate industrial significance. He is hopeful that some of the students will come forward with entrepreneurial instincts to take these things out of the campus and make it work at colossal level.
The first part of the work has recently been published in Ceramics International. The subsequent results are under consideration in various engineering and scientific journals.