Surface Probing of Ultra‐Short‐Pulse Laser Filament Cut Window Glass and the Impact on the Separation Behavior. Issue 9 (30th June 2020)

• Record Type: Journal Article
• Authors: Werr, Ferdinand; Veber, Alexander; Brehl, Martin; Bergler, Michael; Werner, Dirk; Eppelt, Urs; Müllers, Ludger; de Ligny, Dominique
• Other Names: Boccaccini Aldo guestEditor.; Göken Mathias guestEditor.; Travitzky Nahum guestEditor.
• Is Part Of: Advanced engineering materials. Volume 22:Issue 9(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-06-30
• Subjects: crack guidances -- filament cleaving -- laser cutting -- surface modifications -- surface roughnesses -- ultra-short-pulse laser filamentations; Materials -- Periodicals; 620.11
• DOI: 10.1002/adem.202000471
• Languages: English
• ISSNs: 1438-1656

Abstract

Abstract : The process of laser filament cutting produces a practical nongap cut which ensures high precision in lateral dimensions at the micrometer scale. Commercially available OptiWhite soda lime silicate glass is filamented using a 1064 nm picosecond pulsed Nd:YAG laser with varying burst energies and focus positions. The filaments are characterized perpendicular to the incident laser beam using scanning electron microscopy (SEM). Maximum roughness R z evaluated with laser scanning microscopy is measured on the cut sides. The characteristic mechanical strength σ of glass cleavage is decreased by a factor of 6 with the presence of the filaments. This σ obtained in the four‐point‐bending setup decreases with the increase in energy deposited in the material by the laser. It is found that the cleaving cracks are guided by the filament only if the network of microcracks is sufficiently developed. A threshold of the cleaving guidance is linked to a critical surface modification width of 2.5 μm which corresponds to half the distance between filaments. The influences of the laser parameters, sample thickness, and sample position in respect of the focal plane on the cut quality are studied. Guidelines are given to define a suitable parameter set. Abstract : A laser filament glass cutting process is investigated. The analyzed surfaces, treated with varying burst energies and focus positions, show several shapes of surface modifications. By linking the surface modifications to intrinsic properties, roughness of the cut edge or mechanical strength predictions of these properties are possible. The given guidelines help adjust the laser parameters accordingly.