Composite Surface Preparation Using Femtosecond Laser Ablation
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Solution Overview
Problem
Current methods for preparing cured composite surfaces, such as sanding and plasma cleaning, are labor-intensive and produce undesirable waste, while laser ablation introduces heat-affected zones that weaken the structure and inhibit optimal bonding due to excessive pulse duration.
Innovation Solution
The use of ultra-short pulse lasers, like Femto-second lasers, to ablate material without heat-affected zones, increasing surface roughness, cleaning contaminants, and selectively removing matrix material to expose surface fibers, thereby enhancing thermal and electrical conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional laser ablation is used to prepare composite surfaces, then surface roughness is increased and contaminants are removed, but heat-affected zones are created that weaken the structure and inhibit bonding
Solution Approach 1:
The patent changes the pulse duration parameter of the laser from conventional longer pulses to ultra-short pulses (femtosecond range), which fundamentally alters the ablation mechanism to prevent heat diffusion and eliminate heat-affected zones while maintaining effective surface roughening and contaminant removal
Solution Approach 2:
The patent uses pulsed laser action with ultra-short duration cycles, where the laser delivers energy in extremely brief bursts that allow the material to ablate before heat can diffuse to surrounding areas, creating a clean ablation process without thermal damage
2Manufacturing precision
If sanding is used to prepare composite surfaces, then surface roughness is increased for bonding, but labor time and operator variability increase
Solution Approach 1:
The patent replaces the mechanical sanding process with an optical laser ablation process, eliminating the need for manual labor and operator intervention while achieving consistent surface preparation through automated laser scanning and processing
Solution Approach 2:
The laser ablation process is self-regulating through the physics of ultra-short pulse interaction with the material, where the ablation depth and surface morphology are determined by the laser parameters and material properties rather than operator skill, eliminating variability
3Manufacturing precision
If peel-ply layers are used to roughen composite surfaces, then surface texture is improved, but labor intensity and waste production increase
Solution Approach 1:
The patent extracts and eliminates the peel-ply consumable layer from the process, using laser ablation to directly modify the composite surface without requiring additional sacrificial materials, thereby eliminating the waste stream associated with peel-ply disposal
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
This process improves thermal and electrical pathways in treated composites, allowing for efficient heat dissipation and electrical conductivity when bonded, reducing operator variability and waste production.
Implementation Method 1
the excessive pulse duration of the laser, which inhibits the coulomb explosion needed to perform athermal ablation
Implementation Method 2
uses ultra-short pulse lasers, for example, a Femto-second (fs) laser to ablate material without the detrimental heat affected zones of other laser processes
Implementation Method 3
the excessive pulse duration of the laser, which inhibits the coulomb explosion needed to perform athermal ablation
Implementation Method 4
By exposing the surface fibers, through-bond thermal conductivity and surface electrical conductivity is also increased
Implementation Method 5
By exposing the surface fibers, through-bond thermal conductivity and surface electrical conductivity is also increased
Data Source
AI summary
The present invention discloses cured composites having improved surfaces and processes of making and methods of using same. Such processes use ultra-short pulse lasers, for example, a femto-second laser to ablate material without the detrimental heat affected zones of other laser processes. Such process can not only increases surface roughness and clean contaminates, but can also selectively remove the matrix material and expose the surface fibers of cured composites. The treated cured composites have improved thermal and electrical pathways that can dissipate unwanted heat and electricity when two or more prepregs and/or cured composites are bonded or cured to form a single article.