Particle Injection Moulding Die with Internal Temperature Control
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Solution Overview
Problem
The existing particle injection moulding (PIM) process for manufacturing ceramic cores for gas turbine blades often results in surface defects due to temperature inconsistencies, particularly in internal features, which can lead to defects from the ceramic core material adhering to the die during cooling.
Innovation Solution
A die apparatus with an internal feature forming element that incorporates a temperature control circuit, including micro-channels for coolant flow or phase-change substances, to regulate the thermal environment during the solidification of the core, reducing surface defects and enabling more complex ceramic core designs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the die is maintained at a higher temperature to allow the ceramic paste to remain fluid during injection, then the ease of manufacture is improved, but surface defects occur due to the ceramic core material adhering to the die during cooling
Solution Approach 1:
The patent applies local quality by implementing temperature control circuits specifically at the internal feature surfaces where defects occur, rather than uniformly controlling the entire die temperature. This allows the bulk die to remain at injection temperature while localized cooling prevents adhesion at critical surfaces.
Solution Approach 2:
The temperature control circuits are activated during the injection and cooling process to preemptively prevent adhesion before it occurs. By controlling the temperature at internal feature surfaces during the critical cooling phase, the patent prevents the ceramic material from adhering to the die.
2Manufacturing precision
If the die temperature is reduced to prevent adhesion, then surface quality is improved, but the ceramic paste cannot remain fluid during injection
Solution Approach 1:
The patent implements differential temperature control where different regions of the die are maintained at different temperatures. The bulk die and internal feature surfaces are cooled to prevent adhesion, while the injection zone maintains higher temperature to keep the ceramic paste fluid.
Solution Approach 2:
The temperature control system is segmented into multiple independent circuits that can be controlled separately. This allows the die to be divided into zones with different temperature requirements - the injection zone remains hot while the internal feature surfaces are cooled.
3Productivity
If conventional cooling circuits are used to maintain uniform die temperature, then the productivity is improved, but temperature inconsistencies occur in internal features leading to defects
Solution Approach 1:
The patent transitions from uniform temperature control to localized temperature control. Temperature control circuits are positioned specifically at internal feature surfaces where temperature inconsistencies cause defects, allowing precise local temperature management while maintaining overall production efficiency.
Solution Approach 2:
The temperature control circuits provide feedback control by monitoring and adjusting the temperature at internal feature surfaces during the injection and cooling process. This ensures temperature uniformity at critical locations while maintaining the productivity benefits of controlled cooling.
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 surface defects in internal features of ceramic cores, allowing for more intricate designs that can enhance gas turbine efficiency and lower specific fuel consumption by maintaining precise temperature control during the PIM process.
Implementation Method 1
introducing temperature control via a medium contained in the temperature control circuit whereby to control the thermal environment adjacent the internal feature during solidification of the core
Data Source
AI summary
A die for moulding a core by a PIM process, the core having at least one internal feature, the die including; a first die part defining a first portion of an outer surface of the core; a second die part defining a second portion of the outer surface of the core; and an internal feature forming element for defining the surface of an internal feature of the core; wherein the internal feature forming element incorporates a temperature control circuit.