Josiah Cherian Chekotu is a PhD researcher under the Advanced Metallic Systems Centre for Doctoral Training with I-Form. His research is in the area of additive manufacturing of advanced metals. He obtained his undergraduate degree in Mechanical Engineering from University of Kerala in India. Later, he completed his MSc in Mechanical Engineering at Sultan Qaboos University in Oman, performing research in the area of metal extrusion. His main research interests are in the areas of metal additive manufacturing, material characterisation, product design and modeling, and process simulation. He has assisted in editorial works for book chapters, and has multiple peer-reviewed journal publications and conference papers.
Research Interests (Lay Summary)
Josiah is working on the development of additive manufacturing processes for Nickel titanium (Nitinol) components. Nitinol is an intermetallic shape memory alloy with a wide range of applications, including medical devices and heat exchangers. Josiah’s research is focussed on maximising the efficiency of heat pumps, measured as Coefficient of Performance (COP). Nitinol absorbs a significant amount of heat when it’s bent out of shape, then releases that heat when it reverts to its normal shape. Josiah is exploring the development of additively manufactured nitinol complex geometries aimed at maximising the surface area in order to get higher heat transfers.
The additive manufacturing of nitinol alloys has not been as extensively investigated as stainless steel or nickel superalloys. The effect of heat treatment on phase transformations, the characterisation of AM produced Nitinol components and the development of a comprehensive understanding of the effect of various AM process parameters and heat treatments on final part properties are all being investigated in this research project.
To maximise the COP of the heat pump, it is necessary to understand the energy absorbed/released during the solid-state phase transformations. Then, it is required to investigate and propose an efficient additive manufacturing process design. Josiah’s work has three primary objectives: investigation of effect of heat treatment in activating the functional properties and enhancing the stability under compression loads; characterisation of Nitinol powder feedstock, along with optimising the Selective Laser Melting process parameters for fabricating Nitinol; and designing and process optimisation for printing complex Nitinol structures which maximises surface area for heat transfer.