Laser Densification Modeling

Abstract

A three-dimensional transient model for heat conduction in silica glass is developed. The model simulates a three-dimensional temperature distribution in a silica glass irradiated by a moving CO2 laser. Both the reflectivity of the glass surface and the strong attenuation of the laser energy in the glass medium are accounted for by a detailed radiation analysis. The energy absorbed by the glass is determined to be confined in a 10 μm thickness; the laser irradiation is thus treated as a boundary condition. The heat diffusion equation is solved by an alternating direction-implicit method.

Creation of Bioactive Glass Coating on Titanium by Local Laser Irradiation; Part 2: Effect of the Irradiation on the Bioactivity of the Glass

“…Thus, a focused CO 2 -laser beam can be applied for the melting of a bioactive glass powder on grit blasted titanium substrate. A momentary heat exposure hits one area of the surface at a time and affects primarily the uppermost glass [5]. As a result, a glass coating is obtained consisting of repeated rows of melted glass micro spheres attached to the titanium substrate.…”

Creation of Bioactive Glass Coating on Titanium by Local Laser Irradiation; Part 1: Optimization of the Processing Parameters

“…Alternatively, a local application of heat to melt the glass on the substrate can be achieved by the use of a CO 2 laser. As the heat treatment occurs locally and rapidly, it primarily affects the glass layer [6]. Thus, the risk for the oxidation of the substrate underneath is lower compared to that caused by a conventional heat treatment.…”

Microstructure of Laser-Fired, Sol−Gel-Derived Tungsten Oxide Films

“…The disadvantage of furnace-firing is that the whole coated sample is subjected to the same firing temperature. Absorbed laser radiation provides another method of heatingone that is localized to the point of irradiation. , Laser densification of sol−gel-derived coatings has been shown to be successful for making hard, protective coatings , and optical waveguides. − The localized heat source that lasers provide has two advantages in firing sol−gel coatings: (1) the substrate may only be heated slightly, allowing low-refractory materials to be used as substrates; (2) the coating may be selectively heated. The latter consideration allows areas of the same coating to have different properties based on varied firing conditions.…”