Rounded Edge Coating for Turbomachine Blade Tip Fatigue
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing coating methods for turbomachine components, such as blade tips, result in excess material accumulation at sharp edges during galvanic deposition, leading to lateral overhangs that can cause mechanical strain and crack propagation under dynamic loads, compromising the vibrational fatigue strength of the component.
Innovation Solution
The method involves rounding the edges where the first surface adjoins the second surface before coating, using a combination of brushing and grinding to create a smooth contour with a radius of curvature that is at least 0.5 times the coating thickness, preventing excess material deposition and overhangs during galvanic deposition, and applying a metal matrix coating like Ni/cBN for thermal and mechanical protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If galvanic deposition is applied to a sharp edge, then coating material accumulates excessively at the edge, but this creates lateral overhang that reduces vibrational fatigue strength
Solution Approach 1:
The edge is rounded before the coating process to prevent excess material accumulation during galvanic deposition. This preliminary geometric modification ensures uniform coating thickness and eliminates the conditions that lead to lateral overhang, thereby maintaining vibrational fatigue strength.
Solution Approach 2:
Sharp edges are replaced with rounded edges having a specific radius of curvature. This curvature prevents the concentration of electric field lines at the edge during galvanic deposition, eliminating the root cause of excess material accumulation and subsequent lateral overhang that compromises structural strength.
2Strength
If edge rounding is performed before coating, then excess material accumulation is prevented, but additional processing steps are required
Solution Approach 1:
Edge rounding is integrated into the pre-coating preparation process, performing the geometric modification before galvanic deposition. This preliminary action prevents the need for subsequent corrective operations and ensures the coating process proceeds uniformly without excess accumulation.
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 approach reduces the risk of crack initiation and propagation, enhancing the vibrational fatigue strength of the component by ensuring the coating is flush with the surface, thereby preventing mechanical failure under dynamic loads.
Implementation Method 1
excess accumulation of material at the edge, which could ensue, for example, in a galvanic deposition process from a concentration of field lines at the unrounded, sharp edge
Implementation Method 2
using a combination of brushing and grinding to create a smooth contour
Data Source
AI summary
The present invention is directed to a method for coating a component, wherein the component has a first and a second surface, and wherein the first and the second surface adjoin each other at an edge, in which method i) first of all, the edge between the first and the second surface is rounded, and ii) subsequently, a coating is applied to the first surface.