Laser Surface Remelting of Glass for Compressive Stress Control
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Solution Overview
Problem
Conventional glass tempering methods face limitations in enhancing mechanical properties and reducing defects, particularly due to issues with mechanical stresses and uniform cooling, which restrict the achievable strength and durability of tempered glass.
Innovation Solution
A method involving thermal treatment of vitreous materials using a laser that emits in the mid-IR range, with a specific scanning pattern and temperature control, to create a molten surface layer, improving mechanical properties and reducing defects by generating compressive stresses and a robust finish.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional thermal tempering is used to improve mechanical strength, then fracture stress increases, but uniform cooling is difficult to achieve leading to stress distribution issues
Solution Approach 1:
The patent applies laser irradiation to create a localized modified layer on the glass surface with specific compressive stress characteristics, rather than uniform tempering throughout the entire glass piece. This localized treatment allows precise control of stress distribution in the treated zone without affecting the entire glass structure uniformly.
Solution Approach 2:
The patent replaces the conventional mechanical thermal tempering system (furnace with forced cooling) with a laser-based thermal processing system. The laser provides controlled heating that creates the desired stress profile through localized thermal gradients, eliminating the need for complex forced cooling mechanisms.
2Strength
If laser heating is applied to create molten surface layer, then surface robustness improves, but process complexity increases
Solution Approach 1:
The patent controls the laser processing parameters (power, scanning speed, wavelength in mid-IR range) to precisely achieve the desired molten layer depth and stress profile. By optimizing these parameters, the process creates the robust surface layer without requiring additional equipment or complex multi-step procedures.
Solution Approach 2:
The patent uses continuous laser scanning to create the modified surface layer in a single continuous operation. The laser beam moves continuously across the glass surface, maintaining the glass at the appropriate temperature throughout the treatment zone, which simplifies the process compared to intermittent or multi-stage treatments.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method significantly enhances the mechanical properties of glass, including increased fracture stress values and reduced defect distribution, allowing for improved cutting performance and reduced risk of cracking, while maintaining a smooth surface finish.
Implementation Method 1
irradiating it with a laser which can emit in the mid-IR range of the electromagnetic spectrum
Implementation Method 2
The laser beam 302 is applied... which can emit in the mid-IR range of the electromagnetic spectrum
Implementation Method 3
generating compressive stresses and a robust finish
Data Source
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AI summary
The object of the present invention is a method of modifying a vitreous material; a system adapted for performing said method; and the modified vitreous material obtainable by means of said method. This process improves the mechanical properties of the vitreous material.