Al2O3 Ceramic Pressure Sensor Membrane Production
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current ceramic pressure sensors with Al2O3 deformation bodies face challenges in mass production due to complex and costly shaping processes, and the use of glass-forming sintering aids, which impair mechanical properties and corrosion resistance.
Innovation Solution
A method for producing Al2O3 ceramic measuring membranes using high-purity alumina with controlled impurities and additives, forming a pressable spray granulate, and undergoing uniaxial pressing and sintering to achieve high bending fracture stress and density, while minimizing defects and glass phases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If complex liquid shaping processes (gel casting, pressure filtration) are used to achieve high-density Al2O3 structures, then mechanical strength and purity are improved, but manufacturing complexity and production cost increase significantly
Solution Approach 1:
The patent changes the fundamental parameters of the shaping process by transitioning from liquid-based methods to a dry powder uniaxial pressing method. This involves modifying the physical state of the starting material (from slip to dry granulate) and the processing conditions (from liquid shaping to dry pressing followed by sintering), thereby achieving high density and strength without the complexity of gel casting or pressure filtration
Solution Approach 2:
The patent extracts and eliminates the liquid medium and associated complex processing steps from the shaping process. By removing the liquid slip, gelation agents, and filtration requirements, the method simplifies the manufacturing process while maintaining high green density through direct uniaxial pressing of dry granulate
2Temperature
If glass-forming sintering aids (especially SiO2) are added to reduce sintering temperature, then grain growth is controlled and hardness increases, but corrosion resistance and mechanical properties are impaired
Solution Approach 1:
The patent extracts and removes glass-forming sintering aids (particularly SiO2) from the material composition. By eliminating these additives, the method avoids the formation of glass phases that would compromise corrosion resistance and mechanical properties, achieving sintering without the harmful effects of glass-forming compounds
Solution Approach 2:
The patent changes the chemical composition parameters by strictly limiting SiO2 to ≤2000 ppm and other impurities to ≤200 ppm total. This parameter control enables sintering at appropriate temperatures without relying on glass-forming aids, thereby maintaining both corrosion resistance and mechanical strength
3Productivity
If dry pressing of spray-dried granules is used for mass production, then productivity increases, but green density is insufficient and defects remain after sintering
Solution Approach 1:
The patent applies preliminary action by pre-forming the granulate with optimized properties before pressing. The spray granulation process creates particles with controlled morphology and composition, and the uniaxial pressing is performed on this pre-prepared granulate to achieve high green density, thereby ensuring both productivity and manufacturing precision
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 method enables the production of pressure sensors with improved mechanical strength, reduced defects, and enhanced corrosion resistance, suitable for mass production at reasonable costs.
Implementation Method 1
a sintered body is produced from the pressable granulate in a sintering process
Data Source
Figure 1
Figure 2
AI summary
The invention relates to a method for the production of an elastic deformation body from Al2O3 ceramics, utilizing a highly pure alumina having a maximum of 2000 ppm of MgO1, a maximum of 200 ppm of inorganic contaminants, a specific surface of at least 10 m2/g, a mean grain size of a maximum of 0.3 μm, wherein a homogeneous mixture is created using the alumina and additives by means of aqueous processing, from which a spray granulate that can be compressed is created, which is formed into a homogeneous green body by means of a uniaxial compressing method, the green body being subjected to a sintering process, wherein the resulting elastic deformation body has a bending rupture stress σc, the distribution F (σc ) of which is given by the Weibull parameters σ0 ≥ 800 MPa and m ≥ 24, and has a mean grain size of the sintered material of less than 2 μm, and wherein the sintered material of the deformation body has a density of less than 3.98 g/m2.