BS ISO 17859:2015 pdf download – Fine ceramics (advanced ceramics, advanced technical ceramics) — Measurement method of piezoelectric strain at high electric field.
1 Scope This International Standard specifies the measurement method of piezoelectric strain at high electric field for high power piezoelectric devices. This International Standard is intended to be used to determine the piezoelectric strain coefficient of the materials by measuring strain vs. electric field: — applied electric field: 0 to 2 MV/m; — frequency of electric field: 0,1 to 1 Hz. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60122-1, Quartz crystal units of assessed quality — Part 1: Generic specification IEC 60483, Guide to dynamic measurements of piezoelectric ceramics with high electromechanical coupling EN 50324-1, Piezoelectric properties of ceramic materials and components — Part 1: Terms and definitions EN 50324-2, Piezoelectric properties of ceramic materials and components — Part 2: Method of measurement — Low power 3 Terms and definitions, and symbols 3.1 Terms and definitions For the purposes of this document, the terms and definitions given in IEC 60122-1, IEC 60483, EN 50324- 1, EN 50324-2 and the following apply. 3.1.1 applied wave form shape of voltage applied to specimen as a function of time Note 1 to entry: Triangular waves are used in this International Standard. 3.1.2 signal generator apparatus which controls the applied wave form 3.1.3 power source high-voltage amplifier which generates an electric-field (E-field) applied to the specimen
5.2 Shape and size Specimens are made by cutting out from ceramics or single crystals. The shape of the specimen should be disk or quadrilateral plate, with smooth surfaces. Thickness distribution less than ± 1 % is desirable within the plate. The standard dimensions of the specimen are 0,3 mm – 1,0 mm in thickness, 5 mm – 15 mm in size, and 15 – 25 in the ratio of size to thickness. A desirable example of such disc is 0,5 mm in thickness and 10 mm in diameter. 5.3 Electrodes Electrodes should be deposited on both sides of the specimen plate, leaving the edge region free. This edge region should have an area of less than 10 % of the sample surface. The electrode is desirable with tough adhesion and without deterioration. An example of such electrode metal is Au, Ag and Pt. 5.4 Polarization The specimen should be treated by a poling procedure. Polarized direction should be shown on the specimen surface. Typically the positive side of the sample is marked with a dot or cross. 6 Principle The strain of the specimen is induced by the piezoelectric effect when an electric field is applied between the two electrodes of the specimen. The strain is detected as the thickness variation of the specimen using a displacement meter. The strain vs. E-field curve is drawn, and the piezoelectric constant is calculated from this curve.