Laser Drilling Rear-Space Protection Using Particle-Induced Plasma
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Solution Overview
Problem
During laser drilling or cutting, the backspace behind the laser penetration point is not adequately protected from the concentrated laser beam, leading to unintended material removal or energy escape, which existing methods fail to effectively manage.
Innovation Solution
A fluid with dispersed particles is placed in the rear space, forming a plasma upon laser radiation exposure that absorbs and scatters the energy, preventing further laser penetration and reducing energy density in the original beam direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If laser radiation is used for drilling or cutting, then material removal efficiency is improved, but unintended material removal from other areas occurs
Solution Approach 1:
A fluid containing dispersed particles is introduced as an intermediary substance into the backspace region. This fluid acts as a mediator that absorbs and scatters the penetrating laser radiation through plasma formation, preventing the laser energy from causing unintended material removal in areas beyond the intended penetration point, while allowing the drilling/cutting process to proceed efficiently
2Productivity
If laser radiation penetrates the workpiece, then drilling or cutting is achieved, but laser energy escapes uncontrollably into the environment
Solution Approach 1:
The penetrating laser radiation that would otherwise escape uncontrollably and cause harm is converted into a beneficial plasma formation process. The dispersed particles in the fluid absorb the excess laser energy and transform it into localized plasma, which then dissipates the energy harmlessly through scattering and absorption, converting the harmful uncontrolled energy escape into a controlled energy dissipation mechanism
3Object-affected harmful factors
If a fluid with dispersed particles is introduced into the backspace, then laser radiation protection is improved, but particle material is consumed over time
Solution Approach 1:
The dispersed particles in the fluid are designed as consumable, relatively inexpensive elements that sacrifice themselves by forming plasma and absorbing laser energy. These particles are continuously consumed during the laser drilling/cutting process, requiring periodic replenishment of the fluid, but their low cost and ease of replacement make this an acceptable trade-off for maintaining effective backspace protection
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 plasma effectively dissipates the laser energy, preventing material removal and thermal damage to the workpiece by redirecting and absorbing the energy, thus enhancing backspace protection and reducing the risk of unwanted material interaction.
Implementation Method 1
With sufficiently high instantaneous intensity, the electron shells of the material's atoms are directly ionized, allowing material to be removed without introducing excessive heat into the workpiece
Implementation Method 2
If the laser radiation penetrates the workpiece at one point, it can, without adequate protective measures, unintentionally remove material from other areas of the workpiece or escape uncontrollably into the environment
Implementation Method 3
Particles are selected that form a plasma under the influence of the laser radiation entering the backspace, so that this plasma at least partially prevents the passage of the laser radiation
Implementation Method 4
The plasma is generated by a very high instantaneous intensity, which initially removes electrons from the electron shells of the particles' atoms, thus ionizing these atoms
Implementation Method 5
The energy incident with subsequent laser pulses is partially diffusely reflected and/or scattered, and partially absorbed
Implementation Method 6
The energy incident with subsequent laser pulses is partially diffusely reflected and/or scattered, and partially absorbed
Data Source
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AI summary
A method (100) for laser drilling or laser cutting of a workpiece (1), wherein material of the workpiece (1) is removed (110) by pulsed laser radiation (2), wherein a fluid (4) which at least partially prevents the laser radiation (2) from passing through is provided (120) in a rear space (3) which, as seen in the direction of radiation, is located behind a region (1a) of the workpiece (1) that is to be passed through and into which the laser radiation (2) penetrates when it has passed through this region (1a), wherein this fluid (4) comprises particles (4a) that are dispersed in a solvent (4b), characterized in that particles (4a) that form a plasma (5) under the effect of the laser radiation (2) entering the rear space (3) are chosen (121), and so this plasma (5) at least partially prevents the laser radiation (2) from passing through.