Superalloy Single Crystal Blade Solidification Interface Control
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Solution Overview
Problem
Current directional solidification methods for superalloy single crystal blades face challenges in maintaining a stable solid-liquid interface, leading to increased curvature and frequent occurrence of stray grains, particularly at abrupt changes in the blade's cross-section, which affects the quality and service life of the blades.
Innovation Solution
A directional solidification method that uses a three-dimensional numerical model to optimize the withdrawal speed of the solid-liquid interface, adjusting it based on real-time temperature field variations and geometric characteristics to control the width of the solid-liquid zone and reduce curvature, employing FLUENT numerical simulation software and platinum-rhodium thermocouples for precise temperature monitoring and withdrawal speed adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the withdrawal speed is increased to improve productivity, then the production efficiency is improved, but the solid-liquid interface stability deteriorates and stray grains occur more frequently
Solution Approach 1:
The patent implements dynamic adjustment of withdrawal speed based on real-time monitoring of solid-liquid interface position and shape. The withdrawal speed is continuously optimized to maintain interface stability while maximizing production efficiency, transitioning from static to dynamic control mode.
Solution Approach 2:
The patent establishes a feedback control system that monitors the solid-liquid interface position, shape, and stability in real-time, and adjusts the withdrawal speed accordingly. This closed-loop control ensures the interface remains stable while maintaining high production efficiency.
2Speed
If the cooling rate is increased to accelerate solidification, then the solidification speed is improved, but the temperature gradient becomes steeper and interface curvature increases
Solution Approach 1:
The patent applies different cooling rates to different regions of the mold. The cooling intensity is locally adjusted based on the geometric characteristics of the blade, particularly at abrupt cross-section changes, to maintain a flat solid-liquid interface while achieving rapid solidification.
Solution Approach 2:
The patent dynamically adjusts the cooling rate parameter during the solidification process based on real-time monitoring of interface shape and position. The cooling rate is optimized to maintain interface flatness while achieving high solidification speed.
3Stability of the object's composition
If the temperature gradient is increased to improve directional solidification, then the solidification directionality is improved, but the interface curvature increases and stray grains form
Solution Approach 1:
The patent optimizes the temperature gradient parameter to maintain a balance between directional solidification and interface flatness. The temperature gradient is dynamically adjusted based on real-time monitoring of interface shape and solidification progress.
Solution Approach 2:
The patent implements dynamic control of the temperature gradient field during solidification. The gradient is continuously adjusted to maintain both directional solidification and interface stability, transitioning from static to dynamic temperature field control.
4Ease of operation
If conventional directional solidification methods are used, then the process is simple and easy to operate, but the service life and quality of the blades are insufficient
Solution Approach 1:
The patent introduces real-time monitoring and feedback control of the solid-liquid interface, transforming the simple conventional process into an intelligent controlled process. This maintains ease of operation while significantly improving blade quality and service life through precise interface control.
Solution Approach 2:
The patent implements an automated control system that self-adjusts the withdrawal speed and cooling parameters based on real-time interface monitoring, reducing manual intervention while improving product quality and extending blade service life.
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 method effectively eliminates stray grains and improves the quality and production efficiency of single crystal blades by optimizing the withdrawal speed curve, reducing curvature, and controlling constitutional supercooling, thereby enhancing the performance and service life of the blades.
Implementation Method 1
heat is continuously transferred through the bottom of the casting and the lateral portion of the mold
Implementation Method 2
the cooling rate in the casting and the temperature gradient in front of the solid-liquid interface keep decreasing
Implementation Method 3
employing FLUENT numerical simulation software and platinum-rhodium thermocouples for precise temperature monitoring
Data Source
AI summary
The present invention discloses a directional solidification method for a superalloy single crystal blade based on solid-liquid interface steady control. The method establishes effective criteria for withdrawal speed adjustment, i.e. the related position between a macro solid-liquid interface and a thermal baffle, the range between the dendrite tips at the solid-liquid interface, and the difference between the advance speed of the macro solid-liquid interface and the withdrawal speed. With these criteria, the advance of the solid-liquid interface during directional solidification is simulated and a withdrawal speed curve v(t) for the solid-liquid interface steady advancement was obtained. And then, the single crystal blade was prepared.