Composite magnetically permeable layer for pot, preparation method therefor, and pot
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Solution Overview
Problem
Existing cookware products with induction compatibility often experience uneven heat conduction, leading to high local temperatures that can cause burning or deformation of the cookware bottom.
Innovation Solution
A composite magnetic conductive layer is developed, comprising a magnetic conductive material made of a rare earth oxide and a high-entropy alloy, combined with an auxiliary heat preservation layer formed from iron, aluminum, iron oxide, and aluminum oxide. This layer has an adjustable Curie temperature and low resistivity after becoming paramagnetic, allowing for continuous heating at low power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a magnetic conductive material is added to the outer surface of cookware to achieve induction compatibility, then heating efficiency is improved, but heat conduction becomes uneven causing high local temperatures and risk of burning
Solution Approach 1:
The patent applies parameter changes by modifying the Curie temperature of the magnetic conductive material through compositional adjustments (adding rare earth oxide to high-entropy alloy). This allows the material to transition from ferromagnetic to paramagnetic state at a controlled temperature point, automatically regulating heat absorption and preventing excessive local temperature rise while maintaining efficient induction heating below the Curie point.
Solution Approach 2:
The patent uses composite materials by combining rare earth oxide with high-entropy alloy to create a magnetic conductive material with tailored magnetic properties. This composite structure enables precise control over the Curie temperature, allowing the material to provide efficient heat conduction at operating temperatures while automatically limiting temperature rise through phase transition at the designed Curie point.
2Productivity
If the magnetic conductive layer temperature continues to rise to improve heating performance, then heating speed increases, but dry burning and deformation occur
Solution Approach 1:
The patent implements feedback control through the intrinsic magnetic phase transition of the material. As temperature approaches the Curie point during heating, the material automatically transitions from ferromagnetic to paramagnetic state, causing a sharp decrease in magnetic permeability and electromagnetic induction efficiency. This creates a natural negative feedback mechanism that limits further temperature increase, preventing dry burning and deformation while maintaining high heating speed below the Curie point.
Solution Approach 2:
The patent exploits phase transitions by designing the magnetic conductive material to undergo ferromagnetic-to-paramagnetic phase transition at a specific Curie temperature. This phase change acts as a thermal safety valve: during rapid heating, once the Curie temperature is reached, the phase transition automatically reduces heat absorption capacity, preventing temperature runaway and protecting the cookware from thermal damage while maintaining efficient heating throughout the process.
3Temperature
If the Curie temperature is reduced to prevent overheating, then temperature control improves, but the induction cooker may stop heating due to not sensing the cookware
Solution Approach 1:
The patent applies parameter changes by precisely controlling the Curie temperature within an optimal range through compositional design of the rare earth oxide-high-entropy alloy system. By adjusting the ratio and types of elements, the Curie temperature is tuned to a value that simultaneously achieves temperature control (preventing overheating) and maintains sufficient magnetic permeability at operating temperatures to ensure the induction cooker continuously detects and heats the cookware without interruption.
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 composite magnetic conductive layer prevents dry burning and deformation of the cookware by maintaining a stable low-power heating mode, even after reaching the Curie temperature, and ensures continuous heating without interruption by the induction cooker.
Implementation Method 1
The high-entropy alloy significantly reduces the Curie temperature of the alloy, and the rare earth oxide allows to further reduce the Curie temperature of the high-entropy alloy.
Implementation Method 2
When the heating temperature reaches the Curie temperature, the magnetic conductive layer operates at a low power, thereby preventing the dry burning or other problems that may occur when the temperature of the conductive layer continues to rise
Implementation Method 3
The auxiliary heat preservation layer serves to keep the heating at a low power level and prevents the induction cooker from stopping heating due to not sensing the cookware.
Data Source
Figure 1
AI summary
A composite magnetic conductive layer for cookware, comprising: a magnetic conductive layer, comprising a magnetic conductive material consisting of a rare earth oxide and a high-entropy alloy; and an auxiliary heat preservation layer, arranged on the magnetic conductive layer and formed from iron, aluminum, iron oxide and aluminum oxide. Also provided are a preparation method for the composite magnetic conductive layer, and cookware comprising the composite magnetic conductive layer.