Mullite Glass-Ceramic Composition for Enhanced Mechanical Durability
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Solution Overview
Problem
Glass articles used in electronic devices face challenges in mechanical durability and optical characteristics, requiring materials with improved strength and transparency similar to glass but with enhanced mechanical properties.
Innovation Solution
A glass-ceramic composition comprising specific weight percentages of SiO2, Al2O3, B2O3, Li2O, Na2O, K2O, ZnO, and MgO, with a predominant mullite-type structure, which can be ion exchanged to enhance fracture toughness and elastic modulus while maintaining high transmittance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If glass articles are used in electronic devices, then optical transmittance is maintained, but mechanical durability and scratch resistance are insufficient
Solution Approach 1:
The patent employs glass-ceramic composite material that combines the optical transparency of glass with the mechanical strength of ceramic. The specific composition (40-60 wt% SiO2, 18-35 wt% Al2O3, 12-16 wt% B2O3, etc.) creates a material with mullite-type crystalline phase that provides superior scratch resistance while maintaining optical transmittance suitable for electronic device displays
Solution Approach 2:
The patent modifies the chemical composition parameters of traditional glass by incorporating specific ranges of metal oxides (Al2O3, B2O3, ZnO, MgO, Li2O, Na2O, K2O) to transform the material properties. This compositional adjustment enables the formation of mullite-type crystalline structure during heat treatment, which significantly enhances mechanical durability and scratch resistance while preserving optical characteristics
2Strength
If glass-ceramic composition is used to improve mechanical properties, then fracture toughness and elastic modulus increase, but manufacturing complexity increases
Solution Approach 1:
The patent incorporates preliminary nucleation agents (ZnO, MgO, Li2O, Na2O, K2O) in specific amounts (3-20 wt% total ZnO+MgO, 1-8 wt% total Li2O+Na2O) into the glass-ceramic composition before final processing. These agents prepare the material structure in advance to facilitate controlled crystallization into mullite-type phase during heat treatment, thereby achieving high fracture toughness (greater than 0.70 MPa·m1/2) while managing manufacturing complexity through pre-designed composition
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 glass-ceramic articles exhibit improved mechanical durability and optical transparency, with increased fracture toughness and elastic modulus, making them suitable for electronic device applications.
Implementation Method 1
A glass-ceramic composition comprising specific weight percentages of SiO2, Al2O3, B2O3, Li2O, Na2O, K2O, ZnO, and MgO, with a predominant mullite-type structure, which can be ion exchanged to enhance fracture toughness and elastic modulus while maintaining high transmittance
Implementation Method 2
The optical characteristics of the glass article, such as the transmittance of the glass article, may be an important consideration
Data Source
AI summary
A glass-ceramic article includes: from 40 wt % to 60 wt % SiO2; from 18 wt % to 35 wt % Al2O3; from 12 wt % to 16 wt % B2O3; from 0 wt % to 4 wt % Li2O; from 0 wt % to 5 wt % Na2O; from 0 wt % to 5 wt % K2O; from 0 wt % to 15 wt % ZnO; and from 0 wt % to 8 wt % MgO. The sum of Li2O and Na2O in the glass-ceramic article may be from 1 wt % to 8 wt %. The sum of MgO and ZnO in the glass-ceramic article may be from 3 wt % to 20 wt %. A predominate crystalline phase of the glass-ceramic article may comprise a mullite-type structure.