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Effect of Thermal Softening on Anisotropy and Ductile Mode Cutting of Sapphire Using Micro-Laser Assisted Machining

MetadataDetails
Publication Date2016-12-08
JournalJournal of Micro and Nano-Manufacturing
AuthorsHossein Mohammadi, John Patten
InstitutionsWestern Michigan University
Citations27

Ceramics and semiconductors have many applications in optics, micro-electro-mechanical systems, and electronic industries due to their desirable properties. In most of these applications, these materials should have a smooth surface without any surface and subsurface damages. Avoiding these damages yet achieving high material removal rate in the machining of them is very challenging as they are extremely hard and brittle. Materials such as single crystal silicon and sapphire have a crystal orientation or anisotropy effect. Because of this characteristic, their mechanical properties vary significantly by orientation that makes their machining even more difficult. In previous works, it has been shown that it is possible to machine brittle materials in ductile mode. In the present study, scratch tests were accomplished on the monocrystal sapphire in four different perpendicular directions. A laser is transmitted to a diamond cutting tool to heat and soften the material to either enhance the ductility, resulting in a deeper cut, or reducing brittleness leading to decreased fracture damage. Results such as depth of cut and also nature of cut (ductile or brittle) for different directions, laser powers, and cutting loads are compared. Also, influence of thermal softening on ductile response and its correlation to the anisotropy properties of sapphire is investigated. The effect of thermal softening on cuts is studied by analyzing the image of cuts and verifying the depth of cuts which were made by using varying thrust load and laser power. Macroscopic plastic deformation (chips and surface) occurring under high contract pressures and high temperatures is presented.

  1. 2013 - Experimental Study on Brittle-Ductile Transition in Elliptical Ultrasonic Assisted Grinding (EUAG) of Monocrystal Sapphire Using Single Diamond Abrasive Grain [Crossref]
  2. 2015 - Fractal Analysis of Surface Topography in Ground Monocrystal Sapphire [Crossref]
  3. 2010 - Femtosecond Laser Ablation of Sapphire on Different Crystallographic Facet Planes by Single and Multiple Laser Pulses Irradiation [Crossref]
  4. 2016 - Surface Characterization of Diamond Film Tool Grinding on The Monocrystal Sapphire Under Different Liquid Environments [Crossref]
  5. 2016 - Laser Processing of Sub-Wavelength Structures on Sapphire and Alumina for Millimeter Wavelength Broadband Anti-Reflection Coatings [Crossref]
  6. 2015 - Atmospheric Pressure Plasma Enabled Polishing of Single Crystal Sapphire [Crossref]
  7. 2016 - Study on Planarization Machining of Sapphire Wafer With Soft-Hard Mixed Abrasive Through Mechanical Chemical Polishing [Crossref]
  8. 2017 - Grinding Forces in Micro Slot-Grinding (MSG) of Single Crystal Sapphire [Crossref]
  9. 2015 - Anisotropy of Deformation and Fracture Processes in Sapphire Surface [Crossref]