A national workshop organized Indian Institute of Metals

New Horizons in Metallurgy, Materials, and Manufacturing

A national workshop organized by Indian Institute of Metals
December 14th - 16th 2020

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Development of Subtractive and Additive Manufacturing Processes for Creation and Modification of Surface Features

avatar Prof. Ramesh Kumar Singh Professor at IIT Bombay
  • Bio

    Prof. Ramesh Singh is a Professor at IIT Bombay. His research interests are laser additive manufacturing, ultra-highspeed micromachining, super-finishing, and finite element simulation of manufacturing processes. He is actively involved in design and development of special purpose machines for Indian industry and strategic sector. He has very active association with Indian Industry, such as Ceat Tyres, Axis Microtools, PCI, KGK Diamonds, Bharat Forge, L&T, NTPC etc. He received his PhD from Georgia Institute of Technology, MS from Tufts University and Bachelors from Birla Institute of Technology, Ranchi. He has published more than 180 international journals and peer-reviewed conference publications. He has been awarded 2 Indian and 1 US patents and filed 2 Indian and I US patents. He has guided 16 PhDs and over 70 Masters students. He has received the prestigious Swarnajayanti Fellowship by Department of Science and Technology in Engineering Sciences in 2015 and North American Manufacturing Research Institute outstanding paper award at 44th NAMRC at Virginia Tech in 2016. He is the Associate Editor of the Transactions of Institution of Industrial and Systems Engineers and serves on the Editorial Board of Nature Scientific Reports, JMST Advances and International Journal of Precision Technology.

  • Abstract

    Lithography based micromachining processes have primarily evolved for silicon processing for semiconductor industries. These processes have some inherent limitations in work materials and the feature geometry. In contrast, the subtractive machining can create 3-D free-form features in wide range of engineering materials. However, scaling down the subtractive process to micro-scale is extremely challenging due to limited flexural strength/stiffness of the micro-tool. Catastrophic tool failure due to cutting forces is the major impediment in subtractive micromachining. To address these issues, two approaches can be used: laser-induced local thermal softening or ultra- highspeed machining (>100,000 rpm) to reduce the cutting forces. Note that the high-speeds and low flexural stiffness can make the process susceptible to dynamic instability. In addition, additive manufacturing at the micro/meso scale for restoration has immense potential. However, laser direct energy deposition-based repair poses unique technological and scientific challenges with respect to residual stresses due to complex thermomechanical behaviour and metallurgical transformations, dynamic melt-pool spreading and mass transfer due to thermocapillary effect. Addressing, these issues could potentially open novel ways of materials processing at micro/meso scale.