Precision forming of micro-sized piezoceramics with a high aspect ratio

Abstract

<span style="font-size:9.0pt;mso-bidi-font-size:10.0pt;mso-fareast-language: KO" lang="EN-US">In order to fabricate micro-sized PMN-PT piezoceramics with an aspect ratio of 5 for 1-3 composites by injection molding process, two novel methods are developed depending on the size of samples. In the case of a sample with 700 μm in side length of the post, a cassette or monolithic mold is designed and made by machining. The injected samples in the cassette or monolithic mold are effectively separated from the mold by pushing ejecting pins. On the other hand, in the case of sample with 60 μm in side length of the post, PMMA polymer based sacrificial mold inserts are fabricated by using synchrotron radiation. After the injection of PMN-PT powder mixture into the mold inserts, instead of mechanical demolding, PMMA mold inserts are chemically dissolved into acetone. Heat-treating at 800°C in an oxygen atmosphere is more effective for removing organic binders than a conventional de-binding at 500°C in air. Finally, micrometer-scale PMN-PT piezoceramics with the aspect ratio of 5 are successfully fabricated by sintering at 1100°C for 10 h in air.

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