Lead-Free Piezoelectric Composition for Thermal Stability
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Solution Overview
Problem
Existing non-lead based piezoelectric compositions exhibit excellent piezoelectric properties but have not been studied for their temperature variation rate within the range of −40° C. to 85° C., which is crucial for applications in electronic equipment and industry.
Innovation Solution
A piezoelectric composition comprising specific perovskite-type and tungsten bronze-type oxides, with a microstructure that includes manganese and copper, providing a stable and environment-friendly solution with low temperature variation and enhanced piezoelectric properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If non-lead based piezoelectric composition is used to replace lead zirconate titanate, then environmental friendliness is improved, but the stability of piezoelectric properties against temperature variation is insufficient
Solution Approach 1:
The patent employs a composite material system consisting of multiple perovskite-type oxides (first, second, and third perovskite-type oxides with specific compositional ranges) combined in a controlled ratio. This composite structure integrates the advantages of different oxide components to achieve both environmental compatibility (lead-free) and thermal stability (low temperature coefficient of piezoelectric properties), directly resolving the contradiction between environmental friendliness and property stability.
Solution Approach 2:
The patent systematically adjusts and optimizes the compositional parameters of the piezoelectric material, specifically controlling the ratios of different perovskite-type oxides and the content of minor components (0.003≤s≤0.030). By precisely tuning these parameters, the invention achieves a balance between maintaining excellent piezoelectric properties and ensuring low temperature variation, thereby stabilizing the material's performance across temperature ranges while remaining lead-free.
2Reliability
If conventional non-lead based piezoelectric compositions are used, then piezoelectric properties are excellent, but the variation rate against temperature in the range of −40° C. to 85° C. is not controlled
Solution Approach 1:
The invention creates a multi-component composite system where first perovskite-type oxide, second perovskite-type oxide, and third perovskite-type oxide are combined in specific proportions. This composite structure synergistically enhances both the piezoelectric properties and the temperature stability, ensuring that the material maintains reliable performance with minimal variation across the −40° C. to 85° C. range.
Solution Approach 2:
The patent implements precise parameter control by defining specific compositional ranges for each oxide component and limiting the minor component content to 0.003≤s≤0.030. This parameter optimization strategy ensures that the piezoelectric material achieves both high reliability (excellent piezoelectric properties) and low temperature coefficient (controlled variation rate), simultaneously satisfying both 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 composition achieves excellent piezoelectric properties with a low variation rate across the specified temperature range, making it suitable for electronic equipment and industry applications while being environmentally friendly by minimizing lead usage.
Implementation Method 1
An actuator using a piezoelectric composition is an element taking advantage of a piezoelectric phenomenon that a mechanical strain and a stress are generated when an electric field is applied
Data Source
AI summary
The present invention aims to provide a piezoelectric composition containing a composition represented by formula (5) as the main component, wherein the composition represented by formula (5) contains a first perovskite-type oxide represented by formula (1), a second perovskite-type oxide represented by formula (2), a tungsten bronze-type oxide represented by formula (3) and a third perovskite-type oxide represented by formula (4), (K1-x-yNaxLiy)q(Nb1-zTaz)O3 (1), SrZrO3 (2), Ba(Nb1-wTaw)2O6 (3), (Bi0.5Na0.5)TiO3 and/or (Bi0.5K0.5)TiO3 (4), (1−m−n−p)A+mB+nC+pD (5); in formula (1), 0.20≤x≤0.80, 0.02≤y≤0.10, 0.01≤z≤0.30 and 0.800≤q≤1.050; in formula (3), 0.01≤w≤0.30; and in formula (5), A represents the composite oxide represented by formula (1), B represents the composite oxide represented by formula (2), C represents the composite oxide represented by formula (3), D represents the composite oxide represented by formula (4), and 0.04≤m≤0.07, 0≤n≤0.010 and 0.001≤p≤0.020.