Enhancing the tribological performance of Gray Cast Iron by Femtosecond Laser Surface Textured Micro-Crosshatch Patterns
Date26th Mar 2024
Time03:00 PM
Venue (Hybrid mode) MES Seminar Hall / Google meet link – https://meet.google.com/eit-umae-dro
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Details
Laser surface texturing process involves the creation of microfeatures, e.g., tiny dimples, usually distributed in a particular pattern, covering only a fraction of the surface of the material that is being treated. This process offers several advantages for tribological applications, including improved load capacity, wear resistance, lubrication lifetime, and reduced friction coefficient. In the present study, surface texturing of Gray Cast Iron coupons, using femtosecond Laser irradiation, is adopted to establish an optimal geometric pattern with micro-crosshatch features and dimensions, to improve wear and friction behavior. The effect of a range of process parameters, such as pulse energy, scan velocity, textured density, and aspect ratio, on the performance characteristics of laser-textured samples was investigated. The ultrafast laser irradiation with a pulse duration of 100 fs and wavelength of 800 nm creates micro-crosshatches with surface chemistry modification and formation of graphite film and/or opens up the graphite flakes on the surface. The laser surface textures were examined using an Opto-digital 3D microscope and Field Emission Scanning Electron Microscope. In dry conditions, the tribological characterization of those textured specimens was performed by a ball-on-plate reciprocating tribometer. The textured surfaces cause a significant reduction in friction coefficient (up to 90%) over the untextured sample. The wear scar of the textured surface exhibited a significant reduction of wear debris and was found to be smoother than the untextured sample surface. Among various samples tried, the sample with 60 % texture density and 0.06 aspect ratio gave the best results.
Speakers
Mr. Dudekula Nazeer Basha (ME18D013)
Department of Mechanical Engineering