Laser-Treated Metallic Substrates for Residual Compressive Stress
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gas turbine engine components, particularly piston seal rings (PSRs), experience issues with small rotational and axial movements due to torque, thrust loads, and thermal expansion, leading to insufficient hoop strength and twist resistance, which can result in wear, fatigue, and corrosion.
Innovation Solution
A method involving laser treatment under tensile stress followed by stress relaxation to induce residual compressive stress on the PSR surfaces, forming a lubricious oxide coating to enhance durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the PSR is made with small cross section to be compliant, then ease of operation is improved, but strength is worsened
Solution Approach 1:
The patent applies laser surface treatment to change the physical and mechanical parameters of the PSR surface layer, creating a hardened case that provides enhanced hoop strength and wear resistance while maintaining the overall small cross-section compliance of the seal ring
Solution Approach 2:
The laser treatment creates a composite structure with a hardened surface layer and a softer core material, combining the benefits of surface hardness for strength with the compliance of the underlying soft material
2Ease of operation
If the PSR is made with small cross section to be compliant, then ease of operation is improved, but strength is worsened
Solution Approach 1:
The laser surface treatment modifies the mechanical parameters of the surface layer, increasing hardness and strength to provide improved twist resistance while the seal ring maintains its overall compliance for ease of operation
3Strength
If laser treatment is applied to the substrate, then strength is improved, but manufacturing complexity is worsened
Solution Approach 1:
The patent replaces traditional mechanical surface hardening methods with laser surface treatment, which provides improved wear resistance and strength while actually simplifying the manufacturing process by eliminating the need for separate hardening operations and reducing overall process complexity
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 laser treatment normalizes tensile stress to residual compressive stress, improving the PSR's resistance to wear, fatigue, and corrosion, enhancing the seal's performance and longevity.
Implementation Method 1
laser treating the portion
Implementation Method 2
forms an oxide coating on the substrate
Implementation Method 3
deforming the substrate to place a portion of a first surface of the substrate in tensile stress
Implementation Method 4
while holding the substrate deformed, laser treating the portion
Data Source
AI summary
A method for laser treating a substrate includes: deforming the substrate to place a portion of a first surface of the substrate in tensile stress; and while holding the substrate deformed, laser treating the portion. After the laser treating but before release of the deformation, the first surface may remain in tensile stress. Release of the deformation then at least partially cancels the tensile stress.