Turbine Blade Tip Laser Cladding for Leakage Reduction
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Solution Overview
Problem
Existing turbine blades face challenges with wear and oxidation resistance, leading to increased leakage losses due to relative movement between the rotor and housing, with existing solutions being expensive, complex, or offering inadequate erosion resistance.
Innovation Solution
A turbine blade design featuring a metallic MCrAlY layer on the inner and outer crown edges, with a wear-resistant and oxidation-resistant layer applied using laser deposition welding on the blade tip, overlapping with the metallic layer but not the ceramic thermal barrier coating, ensuring protection against hot gas and frictional contacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thick abradable coatings on the heat shield with protective abrasive coatings on the blade tips are used, then wear resistance is improved, but manufacturing cost and complexity increase
Solution Approach 1:
The protective system is segmented into two distinct zones: the heat shield retains a thick abradable coating for wear accommodation, while the blade tip receives a separate laser-deposited abrasive coating for erosion resistance. This segmentation allows each component to be optimized independently, reducing overall manufacturing complexity while maintaining high wear resistance.
Solution Approach 2:
Different coating qualities are applied to different locations: the heat shield receives a soft, abradable coating that can be rubbed in, while the blade tip receives a hard, abrasive-resistant coating. This local differentiation resolves the contradiction by providing appropriate protection characteristics specifically where needed, avoiding the need for complex uniform coatings throughout.
2Adaptability or versatility
If porous ceramic rub-in layers are applied to the heat shield, then adaptability to blade tips is improved, but erosion resistance deteriorates
Solution Approach 1:
Instead of making the blade tip soft to match the heat shield, the invention inverts the approach by making the blade tip hard and abrasive-resistant while the heat shield remains soft and abradable. This inversion resolves the contradiction by allowing the heat shield to adapt to the blade tip through controlled rubbing, while the blade tip maintains its erosion resistance through the hard abrasive coating.
3Reliability
If laser cladding is used to build abrasive blade tips, then wear resistance is improved, but manufacturing cost increases
Solution Approach 1:
The invention replaces traditional mechanical coating methods with laser deposition technology, which allows for precise, localized application of abrasive coatings directly onto the blade tip. This substitution reduces material waste and processing steps, lowering manufacturing costs while maintaining high wear resistance through controlled laser melting and bonding of abrasive particles.
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 design significantly reduces leakage losses, increases turbine efficiency, and allows for cost-effective manufacturing with minimal adaptation to existing processes, enabling effective retrofitting and new part production while maintaining the integrity of ceramic coatings.
Implementation Method 1
the radially outer blade tip consists of a second, at least one-layer, wear-resistant and oxidation-resistant protective layer constructed by means of known laser deposition welding
Implementation Method 2
constructed by means of known laser deposition welding
Implementation Method 3
the at least one first oxidation-resistant protective layer is a metallic layer, in particular an MCrAlY layer
Data Source
Figure 1~2
Figure 3a~3b
Figure 4~5f
AI summary
The invention relates to a wear- and oxidation-resistant turbine blade (1) and a method for manufacturing this blade. The blade (2) is provided on its surface, at least in certain zones, with at least one first protective layer (4, 4a) made of oxidation-resistant material, wherein this first oxidation-resistant protective layer is a metallic layer (4), in particular an MCrAlY layer, which may optionally be covered by a ceramic thermal barrier layer (5). The metallic first protective layer (4) is arranged at least on the inner and outer crown edge of the blade tip (9), but not on the radially outer blade tip (9).The radially outer blade tip (9) of the turbine blade (1) consists of a second single- or multi-layered wear- and oxidation-resistant protective layer (5) of abrasive material (6) and binder material (7) built up by means of a known laser cladding process, wherein this second protective layer (5) on the blade tip (9) overlaps at least partially with the first metallic protective layer (4) arranged there along the outer and/or inner crown edge.