Titanium Alloy Foil Texture Control for Foldable Display Durability
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Solution Overview
Problem
Reinforcing metal sheets or foils for recent foldable and rollable devices require durability against large curvature, which existing materials struggle to meet, especially when used as reinforcing sheets instead of substrates.
Innovation Solution
A titanium alloy foil with specific texture control and properties, including a thickness of 0.005 mm to 0.200 mm, peak intensity of the 200 plane in X-ray diffraction 5.0 times larger than other crystal structures, and tensile strength between 1,000 MPa and 1,800 MPa, is developed to enhance bending fatigue durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If stainless-steel foil is used as reinforcing sheet, then flexibility is achieved, but bending fatigue durability under large curvature is insufficient
Solution Approach 1:
The invention changes the material parameters by transitioning from stainless-steel foil to titanium alloy foil with specific compositional parameters (Ti-5Al-5V-3Cr-3Mo alloy) and microstructural parameters (grain size control), achieving both flexibility and improved bending fatigue durability under large curvature conditions
Solution Approach 2:
The invention uses a composite material approach by creating a titanium alloy foil with multiple phases (α-phase and β-phase) and controlled grain structures, combining the benefits of flexibility from the foil form factor with enhanced durability from the multi-phase composite microstructure
2Strength
If titanium alloy material is used as reinforcing material, then strength is improved, but bending fatigue durability under severe repeated bending with large curvature is insufficient
Solution Approach 1:
The invention applies local quality control by creating specific microstructural zones within the titanium alloy foil, including controlling the grain size distribution and phase distribution (α-phase and β-phase) to optimize local mechanical properties for bending fatigue resistance while maintaining overall strength
Solution Approach 2:
The invention optimizes the alloy compositional parameters (Ti-5Al-5V-3Cr-3Mo) and processing parameters to achieve a specific microstructure with controlled grain size and phase distribution, resulting in simultaneous improvement of strength and bending fatigue durability
3Weight of moving object
If thin metal foil is used to reduce device weight, then weight is reduced, but durability against large curvature is compromised
Solution Approach 1:
The invention changes the material parameters by using titanium alloy foil with optimized thickness (0.03mm to 0.1mm) combined with specific compositional parameters (Ti-5Al-5V-3Cr-3Mo) and microstructural parameters, achieving high strength-to-weight ratio and improved durability against large curvature while maintaining thin profile for weight reduction
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 titanium alloy foil provides high bending fatigue durability, enabling the construction of thin, lightweight, and highly durable display panels for foldable and rollable electronic devices, with minimal fatigue cracks and small bending habit even under severe repeated bending conditions.
Implementation Method 1
in X-ray diffraction intensities obtained when X-ray diffraction is performed on a surface, the peak intensity of a 200 plane of a crystal of a body-centered cubic structure is 5.0 times or larger a maximum peak intensity from other crystal structures
Data Source
AI summary
A titanium alloy foil, wherein when a thickness is represented by t, the t is 0.005 mm or more and 0.200 mm or less, in X-ray diffraction intensities obtained when X-ray diffraction is performed on a surface, a peak intensity of a 200 plane of a crystal of a body-centered cubic structure is 5.0 times or larger a maximum peak intensity from other crystal structures, in X-ray diffraction intensities of the crystal of the body-centered cubic structure among the X-ray diffraction intensities, the peak intensity of the 200 plane or a peak intensity of a 211 plane is larger than a peak intensity of a 110 plane, and a tensile strength is 1,000 MPa or more and 1,800 MPa or less.