1-3 piezoelectric composites for high temperature transducer applications

Area of Science:

• Materials Science
• Ceramics
• Polymers

Background:

• 1-3 composites based on lead zirconate titanate (Pb(Zr,Ti)O3) and epoxy are crucial for various applications.
• High-temperature performance and thermal reliability are critical limitations for these composites.

Purpose of the Study:

• To enhance the thermal reliability of Pb(Zr,Ti)O3/epoxy 1-3 composites at elevated temperatures.
• To investigate the effect of glass sphere modification in epoxy fillers on composite properties.

Main Methods:

• Fabrication of Pb(Zr,Ti)O3/epoxy 1-3 composites using the dice and fill method.
• Modification of epoxy filler with varying volume percentages of glass spheres.
• Aging composites at 250°C with different dwelling times and measuring temperature-dependent dielectric and electromechanical properties.

Main Results:

• Unmodified epoxy composites showed cracking and electrode damage after 200 hours at 250°C, leading to failure.
• Composites with >12 vol% glass sphere loaded epoxies exhibited minimal property variation after 500 hours of aging.
• Key properties for modified composites included dielectric permittivity (~940), piezoelectric coefficient (~310 pC/N), and electromechanical coupling (~57%).

Conclusions:

• Incorporating glass spheres into the epoxy filler significantly improves the thermal stability and reliability of Pb(Zr,Ti)O3/epoxy composites.
• The enhanced thermal expansion behavior of the modified filler is responsible for the improved high-temperature performance.
• Modified composites demonstrate potential for applications requiring sustained performance at elevated temperatures.