A study on the micromachining of molybdenum using nanosecond and femtosecond lasers

  • Mobin M. Mathew
  • Ravi N. Bathe
  • G. Padmanabham
  • R. PadmanabanEmail author
  • S. Thirumalini


Laser micromachining is an advanced machining process in which machining is achieved by focusing a laser beam to melt and vaporize the material. The primary aim of this work is to fabricate a control grid for an electron gun using laser micromachining. Initially, line scribing and 2D profiling experiments are performed on a 130-μm molybdenum plate to compare the surface quality and material removal rate of nanosecond and femtosecond lasers. The effects of laser processing parameters such as average power, repetition rate, and the feed rate on the width, depth, material removal rate, and cut quality of both the nanosecond and femtosecond lasers are studied. During micromachining using the nanosecond laser, melting and recasting of the metal around the machined sites are observed, resulting in the formation of heat-affected zone. During machining using the femtosecond laser, ultrafast laser pulses are used, which result in the absence of heat-affected zone. The surface roughness obtained using the femtosecond laser for creating a 2D profile is 0.187 μm, while using the nanosecond laser, the roughness value obtained is 1.89 μm. The femtosecond laser is used to successfully machine the 3D profile of the control grid, adopting the optimized parameters obtained from the line scribing and 2D profiling experiments. The average width of the grid line was measured as 149.89 μm which is very close to the required dimension of 150 μm.


Laser micromachining Line scribing 2D profiling Heat-affected zone Surface roughness 


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© Springer-Verlag London Ltd., part of Springer Nature 2017

Authors and Affiliations

  • Mobin M. Mathew
    • 1
  • Ravi N. Bathe
    • 2
  • G. Padmanabham
    • 2
  • R. Padmanaban
    • 1
    Email author
  • S. Thirumalini
    • 1
  1. 1.Department of Mechanical EngineeringAmrita School of Engineering, CoimbatoreAmrita Vishwa VidyapeethamIndia
  2. 2.Center for Laser Processing of MaterialsARCIHyderabadIndia

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