Epoxy Slip Curing for Turbine Blade Casting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing ceramic slips for metal investment casting require high temperatures for solidification, limiting the use of wax templates and increasing production costs, especially for complex geometries like those in gas and power turbines.
Innovation Solution
A ceramic slip is developed using a mixture of epoxy resin and sterically hindered amines as a curing agent, allowing for low-temperature solidification (below 70°C) without the need for accelerators, enabling the use of wax templates and reducing energy consumption and mold damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If high-temperature curing (above 130°C) is used for epoxy resin polymerization, then complete curing and sufficient strength are achieved, but energy consumption increases and wax templates melt
Solution Approach 1:
The patent changes the curing temperature parameter from conventional high temperatures (above 130°C) to low temperatures (below 70°C, preferably 20-50°C) by selecting a specific sterically hindered amine hardener with reduced reactivity, thereby avoiding wax template melting and reducing energy consumption while still achieving complete curing
Solution Approach 2:
The patent applies local quality by using a sterically hindered amine hardener with specific molecular structure (bulky groups at beta-position) that provides controlled reactivity, enabling low-temperature curing without requiring high energy input, thus differentiating the curing behavior from conventional epoxy systems
2Productivity
If conventional amine hardeners are used with epoxy resin, then rapid curing occurs, but processing time becomes too short for complex slip formulations
Solution Approach 1:
The patent modifies the reaction kinetics parameter by using a sterically hindered amine hardener with bulky groups (e.g., adamantyl, bornyl, isobornyl) at the beta-position, which reduces the curing rate to extend processing time from minutes to several hours, while still achieving complete curing at low temperatures
Solution Approach 2:
The patent creates a dynamic balance between processing time and curing completion by selecting a hardener that provides intermediate reactivity - slow enough to allow thorough mixing and complex formulation processing, but fast enough to complete curing within practical timeframes at low temperatures
3Strength
If high-temperature curing is applied to achieve complete polymerization, then sufficient green body strength is obtained, but reaction shrinkage increases and dimensional precision deteriorates
Solution Approach 1:
The patent changes the temperature parameter to low-temperature curing (20-50°C) which reduces thermal expansion and reaction shrinkage, thereby improving dimensional precision and surface quality of the green body while still achieving complete polymerization and sufficient strength through the extended processing time enabled by the sterically hindered amine
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 enables the production of stable green bodies at low temperatures, extending processing time, reducing reaction shrinkage, and allowing for multi-layer designs, thus enhancing the cost-effectiveness and precision of complex metal blade production in turbines.
Implementation Method 1
the first binder comprises a mixture of at least one epoxy resin and at least one sterically hindered amine as a hardening agent
Implementation Method 2
By warm or hot curing at up to 160°C, the first binder or binder component polymerizes
Implementation Method 3
a powder conglomerate of various inorganic components, sinterable at high temperatures, is dispersed in a solvent
Implementation Method 4
By applying vacuum and vibration, the solvent, which primarily serves to reduce viscosity, is removed
Implementation Method 5
the filler powder fraction is sedimented and compacted according to the maximum packing density
Implementation Method 6
Up to 300°C, the first binder component pyrolyzes and is largely driven off in the form of gaseous oxidation products
Implementation Method 7
the first binder component polymerizes and gives the resulting green body the geometry
Implementation Method 8
This component vitrifies from approximately 250°C to approximately 500°C, releasing volatile components and forming an inorganic network that encapsulates and thus fixes the completely debound sintered ceramic powder
Implementation Method 9
In a final temperature step, the ceramic is produced through high-temperature sintering
Data Source
Figure 1
AI summary
The invention relates to a method (S1, S1a, S1b, S1c) used to produce a slip, wherein at least one inorganic component is mixed with at least one first binder and the first binder comprises a mixture of at least one epoxy resin and at least one sterically hindered amine as a curing agent. The invention also relates to a component produced by means of said slip. The invention can be used, in particular, for producing complex metal blades in all types of gas and drive turbines in an economical manner.