Composite Preforms for High-Temperature Superalloy Wear Pads
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Turbine blade Z-notch contact faces experience wear and erosion, and existing wear pads fail to maintain bonding at high temperatures during repair and rejuvenation processes, leading to increased costs and downtime due to slumping or falling off.
Innovation Solution
Composite preforms comprising specific powder alloy compositions, such as those with varying percentages of nickel, cobalt, chromium, molybdenum, and other elements, are used to metallurgically bond alloy wear plates or pads to superalloy articles, providing high temperature stability and resistance to deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wear pads are applied to Z-notch contact faces, then wear resistance is improved, but the pads slump and fall off at temperatures above 1200°C during repair processes
Solution Approach 1:
The invention changes the chemical composition parameters of the bonding alloy to achieve high-temperature stability. Specifically, it uses a cobalt-based alloy with 15-25 wt% chromium, 10-20 wt% molybdenum, 0.5-3 wt% boron, and other elements in controlled amounts, which maintains bond integrity at temperatures above 1200°C during repair processes
Solution Approach 2:
The invention uses a composite material system consisting of a cobalt-based bonding alloy combined with specific ceramic additives (such as boron compounds) to create a multi-phase material that exhibits both strong bonding capability and high-temperature stability, preventing pad slumping and detachment
2Reliability
If high heat input weld overlay processes are used, then wear resistance is improved, but the substrate becomes embrittled in the heat-affected zone
Solution Approach 1:
The invention applies local quality by using a controlled heat input process that concentrates thermal energy only in the immediate bonding zone rather than creating a large heat-affected zone. The specific alloy composition (with 0.5-3 wt% boron and 10-20 wt% molybdenum) is designed to achieve bonding with minimal thermal exposure, preserving the ductility of the nickel-based superalloy substrate while providing wear resistance at the contact surface
3Productivity
If thermal spray processes are used, then application efficiency is improved, but substantial clean-up is required and the bond is primarily mechanical rather than metallurgical
Solution Approach 1:
The invention replaces the mechanical bonding mechanism of thermal spray processes with a metallurgical bonding mechanism. By using a cobalt-based alloy composition (with 15-25 wt% chromium and 0.5-3 wt% boron) that forms strong metallurgical bonds with nickel-based superalloys, the process achieves both efficient application and strong bonding without requiring substantial clean-up operations
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 solution ensures strong metallurgical bonding and prevents deformation of wear pads during high-temperature processes, maintaining wear resistance and reducing the need for frequent repairs and downtime.
Implementation Method 1
The composite preform is positioned between the wear plate and surface of the nickel-based superalloy article to form an assembly. The assembly is heated to metallurgically bond the wear plate to the surface of the nickel-based superalloy article via a bonding alloy formed by the powder alloy composition.
Implementation Method 2
The assembly is heated to metallurgically bond the wear plate to the surface of the nickel-based superalloy article via a bonding alloy formed by the powder alloy composition.
Data Source
AI summary
In one aspect, composite preforms are provided for imparting wear resistance to superalloy articles. The composite preforms can be employed for metallurgically bonding alloy wear plates or pads to superalloy articles. A composite preform, in some embodiments, comprises a powder alloy composition comprising 1-30 wt. % nickel, 0.05-2 wt. % iron, 15-25 wt. % chromium, 10-30 wt. % molybdenum, 0-1 wt. % carbon, 1-5 wt. % silicon, 0.05-2 wt. % boron, 0-5 wt. % tungsten, 0-3 wt. % tantalum, 0-0.1 wt % manganese, 0-3 wt. % aluminum, 0-0.1 wt % yttrium and the balance cobalt.