Lithium Silicate Glass Ceramic Low-Temperature Crystallization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional lithium disilicate glass ceramics require high temperatures for crystallization, consuming significant energy and necessitating the presence of alkali metal oxides like K2O or Na2O for desired properties, which limits their application in dental restorations.
Innovation Solution
Lithium silicate glass ceramics incorporating hexavalent metal oxides such as MoO3 or WO3, allowing crystallization of lithium disilicate at lower temperatures (520-750°C) without alkali metal oxides, achieving suitable optical and mechanical properties for dental use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional lithium disilicate glass ceramics are used, then desired mechanical and optical properties are achieved, but high crystallization temperatures (800-1040°C) are required, consuming significant energy
Solution Approach 1:
The patent changes the chemical composition parameters by incorporating hexavalent metal oxides (MoO3, WO3) as essential components and adjusting the ratios of Li2O, SiO2, and other oxides. This compositional parameter change enables crystallization at lower temperatures (520-750°C) while maintaining the desired mechanical strength and optical properties of lithium disilicate glass ceramics
Solution Approach 2:
The patent creates a composite glass ceramic system by combining lithium disilicate base glass with hexavalent metal oxide additives (MoO3, WO3) and other modifying oxides (Al2O3, P2O5, ZnO). This composite approach allows the hexavalent metal oxides to act as nucleating agents and structure modifiers, enabling low-temperature crystallization while preserving the mechanical and optical properties required for dental applications
2Reliability
If alkali metal oxides (K2O, Na2O) are included to achieve desired glass ceramic properties, then lithium disilicate crystal phase formation is facilitated, but the presence of these components limits application flexibility and requires specific heat treatment protocols
Solution Approach 1:
The patent modifies the chemical composition by incorporating hexavalent metal oxides (MoO3, WO3) as key components that replace or reduce the need for traditional alkali metal oxides. This parameter change in composition enables the formation of lithium disilicate crystal phase through alternative mechanisms, providing greater application flexibility and simplified processing without compromising reliability
Solution Approach 2:
The hexavalent metal oxides (MoO3, WO3) act as intermediary substances that facilitate lithium disilicate crystal phase formation without requiring traditional alkali metal oxides. These intermediaries provide nucleation sites and modify the glass matrix structure, enabling reliable crystal formation while expanding application versatility and reducing processing constraints
3Stability of the object's composition
If high crystallization temperatures are used, then complete crystallization of lithium disilicate is achieved, but processing complexity and energy costs increase
Solution Approach 1:
The patent changes the compositional parameters by incorporating hexavalent metal oxides (MoO3, WO3) that lower the crystallization temperature range to 520-750°C. This parameter change enables complete lithium disilicate crystallization at reduced temperatures, simplifying the manufacturing process while maintaining compositional stability and achieving the desired crystal phase transformation without high-energy requirements
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 enables the production of lithium disilicate glass ceramics with improved mechanical and optical properties at reduced energy costs, suitable for dental restorations, and eliminates the need for alkali metal oxides, facilitating easier processing and reduced energy consumption.
Implementation Method 1
the crystallization of lithium disilicate takes place at lower temperatures of from 520 to 750° C.
Data Source
AI summary
Lithium silicate glass ceramics and glasses containing specific oxides of hexavalent elements are described which crystallize at low temperatures and are suitable in particular as dental materials.