Columnar Thermal Barrier Coating for Low-Stress Heat Insulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing thermal barrier layers for turbine components in aircraft and gas turbines face challenges in controlling columnar structure irregularity and distribution, leading to uneven stress distribution and reduced durability under high temperatures.
Innovation Solution
A ceramic thermal barrier layer system with vertically protruding columns spaced apart to allow for expansion and minimize stress, featuring a method of laser welding to create columns with controlled dimensions and patterns, enabling durable and efficient heat protection up to 1800°C or higher.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If plasma spraying process is used to produce thermal barrier layer, then columnar structures are formed, but the columns have irregular courses and uneven distribution
Solution Approach 1:
The patent replaces the mechanical plasma spraying process with a laser-based process. The laser beam melts and deposits ceramic material in a controlled manner, allowing precise control over column formation, diameter, spacing, and distribution. This substitution of the deposition mechanism enables uniform columnar structures with controlled geometry that cannot be achieved through conventional plasma spraying.
Solution Approach 2:
The patent changes the key process parameters from plasma spraying to laser processing parameters including laser power, scanning speed, hatch spacing, and layer thickness. By controlling these parameters, the process achieves consistent column diameter, uniform spacing, and regular distribution patterns. The laser parameters can be precisely adjusted to optimize column formation and eliminate the irregularities inherent in plasma spraying.
2Temperature
If thermal barrier layer is made thicker to provide adequate heat protection, then thermal insulation improves, but thermal stresses increase due to temperature gradients
Solution Approach 1:
The patent divides the thermal barrier layer into discrete columnar structures with controlled spacing rather than a continuous solid layer. This segmentation creates a porous structure that reduces thermal stress transmission while maintaining adequate thermal insulation. The gaps between columns act as stress relief zones, preventing crack propagation and reducing the overall thermal stress burden on the underlying substrate.
Solution Approach 2:
The patent utilizes a porous columnar structure where the void spaces between columns provide thermal insulation while reducing the material density. This porous architecture allows the layer to accommodate thermal expansion and contraction more effectively, reducing thermal stresses. The controlled porosity maintains insulating properties while improving stress resistance compared to a dense solid layer of equivalent thickness.
3Stress or pressure
If columns are spaced apart to allow expansion and minimize stress, then thermal stress resistance improves, but thermal insulation efficiency may be reduced
Solution Approach 1:
The patent optimizes the spacing and dimensional parameters of the columns to achieve a balance between stress resistance and thermal insulation. By controlling column diameter, height, and center-to-center spacing, the process creates an optimal porosity level that provides sufficient stress relief while maintaining adequate thermal barrier performance. The laser processing parameters are tuned to produce columns with specific geometric ratios that maximize both stress resistance and insulating efficiency.
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 system significantly extends the service life of turbine components by maintaining long-lasting cohesion and providing effective thermal insulation, with columns arranged to optimize heat protection and minimize stress, achieving improved durability and thermal resistance.
Implementation Method 1
a laser beam is used to repair its surface
Implementation Method 2
The thermal barrier layer significantly increases the service life of the substrate. This statement refers to the case where the substrate is regularly exposed to temperatures exceeding 1000° C.
Data Source
AI summary
A system comprising a substrate and a ceramic thermal barrier layer formed of columns which is applied to the substrate, characterized in that the columns are spatially separated from each other at the substrate or at least hardly contact each other is disclosed. A method for producing the system by laser welding is also disclosed. The disclosed material makes it possible to produce durable, heat-resistant components that can be used, for example, in turbines or in metal-supported fuel cells.