Rolled Metal Material for Small Bend Radius and Fatigue Durability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing foldable or curvable parts made of metal plates face challenges in reducing the bend radius while maintaining durability against bending stresses and fatigue from repeated deformations.
Innovation Solution
A rolled material composed of alloys or pure metals, such as beta-type titanium alloys, austenitic stainless steel, or beryllium copper, with a durability index value not smaller than 0.014 HV/GPa, calculated by the equation (0.0048×Vickers hardness + 0.21) / modulus of elasticity, is used to enhance durability and reduce the bend radius.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the bend radius of the metal plate is reduced to save space and improve design, then the compactness and design flexibility are improved, but the bending stress on the metal plate increases, reducing durability
Solution Approach 1:
The patent changes the material parameters by controlling the crystal structure (alpha or beta phase), adjusting the modulus of elasticity to 30-150 GPa, and controlling Vickers hardness to achieve an index value of 0.014 HV/GPa or more. These parameter changes allow the metal plate to withstand high bending stresses while maintaining a small bend radius, thus resolving the contradiction between compactness and durability
Solution Approach 2:
The patent uses alloyed metal plates (such as titanium alloys, aluminum alloys, or steel alloys) with specific compositional ranges to create composite-like properties. By combining multiple elements in controlled proportions, the material achieves both low modulus of elasticity and high fatigue resistance, enabling small bend radius while maintaining durability against repeated bending
2Reliability
If the modulus of elasticity of the metal plate is reduced to decrease strain from bending stress, then the durability against bending repetitions is improved, but the strength and load-bearing capacity may be reduced
Solution Approach 1:
The patent optimizes the modulus of elasticity to a specific range of 30-150 GPa through crystal structure control and alloying. This parameter change reduces strain under bending stress (improving durability) while the concurrent increase in Vickers hardness and fatigue limit compensates for any loss in load-bearing capacity, thus resolving the contradiction between durability and strength
3Reliability
If the Vickers hardness of the metal plate is increased to improve durability, then the resistance to bending stress is improved, but the modulus of elasticity may increase, reducing the durability index
Solution Approach 1:
The patent establishes a specific relationship between Vickers hardness and modulus of elasticity, controlling the index value (Vickers hardness)/(modulus of elasticity) to be 0.014 HV/GPa or more. This allows the material to have high Vickers hardness for durability while keeping the modulus of elasticity in the optimal range of 30-150 GPa, thus resolving the contradiction between durability and stress resistance
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 provides a rolled material with improved durability against bending stresses and reduced bend radius, suitable for foldable or curvable parts in devices like display apparatuses, by increasing the fatigue limit and reducing strain through adjusted modulus of elasticity.
Implementation Method 1
a rolled material to be used for a foldable or curvable part... configured to elastically deform to be foldable or curvable together with the flexible display
Data Source
AI summary
A rolled material includes an alloy or a pure metal, and has an index value, which is used as an index value of durability against bending repetitions, not smaller than 0.014 HV/GPa, the index value=(0.0048×(Vickers hardness)+0.21)/(modulus of elasticity).