09:30 〜 11:30
▼ [20a-P6-5] Investigation of ball-milling and surfactant effects for fabrication of 85(Bi0.5Na0.5)TiO3-15BaTiO3 green ceramics with electrophoretic deposition
キーワード：lead-free piezoelectric, electrophoretic deposition
85(Bi0.5Na0.5)TiO3-15BaTiO3 (85BNT-15BT) ceramic is well-known lead-free prototype piezoelectric ceramic due to its high Curie temperature (~250 oC) and suitability for mass production. However, it is difficult to use in real application because of its low piezoelectric constants (d33 ~ 110 pC/N).
To enhance piezoelectric properties in lead-free piezoelectric ceramics, application of engineered domain structure has been studied. From the literature survey, fine-grained and textured ceramics are found to require for application of engineered domain structure. To fabricate fine-grained and textured ceramics, high-magnetic field electrophoretic deposition (HM-EPD) method has been studied as HM-EPD method can use smaller particle size rather than large template particles. In HM-EPD method, particles in suspension are accumulated along the applied electric field due to surface charges of particles while orientated along magnetic field due to difference of magnetic susceptibility from crystal anisotropy. However, there are only few reports on fabrication of BNT-BT ceramic with HM-EPD method.
In this work, 85BNT-15BT green body was fabricated using EPD method without magnetic field under various suspensions condition such as varying content of PEI (polyethyleneimine, surfactant) and different ball-milling time to yield thick and dense green body. According to the experiment, we concluded that PEI adhesion is changed with PEI content and ball-milling time as shown in figure 1. Thick and dense green body was fabricated under high PEI content and long ball-milling time because PEI was fully covered on particle surface as in figure 1(c). Detailed experimental results will be provided during presentation.
To enhance piezoelectric properties in lead-free piezoelectric ceramics, application of engineered domain structure has been studied. From the literature survey, fine-grained and textured ceramics are found to require for application of engineered domain structure. To fabricate fine-grained and textured ceramics, high-magnetic field electrophoretic deposition (HM-EPD) method has been studied as HM-EPD method can use smaller particle size rather than large template particles. In HM-EPD method, particles in suspension are accumulated along the applied electric field due to surface charges of particles while orientated along magnetic field due to difference of magnetic susceptibility from crystal anisotropy. However, there are only few reports on fabrication of BNT-BT ceramic with HM-EPD method.
In this work, 85BNT-15BT green body was fabricated using EPD method without magnetic field under various suspensions condition such as varying content of PEI (polyethyleneimine, surfactant) and different ball-milling time to yield thick and dense green body. According to the experiment, we concluded that PEI adhesion is changed with PEI content and ball-milling time as shown in figure 1. Thick and dense green body was fabricated under high PEI content and long ball-milling time because PEI was fully covered on particle surface as in figure 1(c). Detailed experimental results will be provided during presentation.