Lead-Free Piezoelectric Ceramic Composition with Copper Oxide
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Solution Overview
Problem
Current lead-free piezoelectric ceramic materials, such as BNT-based and NKN-based materials, exhibit low piezoelectric properties compared to lead-based PZT materials, and there is a need for eco-friendly alternatives with improved performance for high-frequency speaker applications.
Innovation Solution
A lead-free piezoelectric ceramic composition based on (Ba,Ca)(Ti,Zr)O3 (BCTZ) is developed by adding copper oxide (CuO) to the BCTZ-based base material and sintering at temperatures between 1300° C. to 1600° C., with a weight ratio of copper oxide at 0.6 wt %, enhancing piezoelectric properties and speaker characteristics in the high frequency band.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If lead-free piezoelectric ceramic materials (BNT-based or NKN-based) are used as eco-friendly alternatives, then environmental pollution and health hazards are reduced, but piezoelectric properties remain low compared to lead-based PZT materials
Solution Approach 1:
The patent develops a composite lead-free piezoelectric ceramic material with composition (1-x-y)BaTiO3-xCaZrTiO4-yCuO, combining multiple oxide components to achieve both eco-friendliness and improved piezoelectric properties. The composite structure allows synergistic effects that overcome the limitations of individual lead-free materials while maintaining environmental safety.
Solution Approach 2:
The patent optimizes specific compositional parameters (x and y values in the formula) and sintering temperature parameters to maximize piezoelectric properties. By systematically varying these parameters and identifying optimal ranges, the material achieves d33 values of 150-250 pC/N, significantly improving performance while remaining lead-free.
2Reliability
If copper oxide is added to BCTZ-based base material and sintered at high temperatures (1300°C to 1600°C), then piezoelectric properties are improved, but manufacturing complexity and energy consumption increase
Solution Approach 1:
The patent incorporates copper oxide into the base material composition before sintering, allowing the additive to be uniformly distributed throughout the material matrix. This preliminary incorporation simplifies the manufacturing process by eliminating the need for post-sintering treatments or multiple processing steps, reducing overall manufacturing complexity despite the high sintering temperature requirement.
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 BCTZ-based lead-free piezoelectric ceramic composition achieves improved piezoelectric properties and high gain in the high frequency band, providing ultra-high sound quality for speakers and earphones without the use of lead, addressing environmental concerns and performance limitations of existing materials.
Implementation Method 1
sintering the mixture at a temperature of 1300° C. to 1600° C. for 1 to 5 hours
Data Source
AI summary
Disclosed are a BCTZ-based lead-free piezoelectric ceramic composition and a method of preparing a BCTZ-based lead-free piezoelectric ceramic which provide high piezoelectric properties and speaker characteristics. The method of preparing a lead-free piezoelectric ceramic includes preparing a mixture in which copper oxide is added to a BCTZ-based base material and sintering the mixture at a temperature of 1300° C. to 1600° C. for 1 to 5 hours, wherein a weight ratio of the copper oxide in the mixture is 0.6 wt %.