1、BRITISH STANDARD BS EN 50324-1:2002 Piezoelectric properties of ceramic materials and components Part 1: Terms and definitions The European Standard EN 50324-1:2002 has the status of a British Standard ICS 31.140 BS EN 50324-1:2002 This British Standard, having been prepared under the direction of t
2、he Electrotechnical Sector Policy and Strategy Committee, was published under the authority of the Standards Policy and Strategy Committee on 10 October 2002 BSI 10 October 2002 ISBN 0 580 40539 7 National foreword This British Standard is the official English language version of EN 50324-1:2002. Th
3、e UK participation in its preparation was entrusted by Technical Committee GEL/15, Insulating materials, to Subcommittee GEL/15/3/1, Ceramics and glass, which has the responsibility to: A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-refere
4、nces The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British
5、Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to
6、 the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside
7、 front cover, the EN title page, pages 2 to 15 and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEAN STANDARD EN 50324-1 NORME EUROPENNE EUROPISCHE NORM May 2002 CENELEC Euro
8、pean Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels 2002 CENELEC - All rights of exploitation in any form and by any means reserved worldwide fo
9、r CENELEC members. Ref. No. EN 50324-1:2002 E ICS 31.140 English version Piezoelectric properties of ceramic materials and components Part 1: Terms and definitions Proprits pizolectriques des matriaux et composants en cramique Partie 1: Termes et dfinitions Piezoelektrische Eigenschaften von keramis
10、chen Werkstoffen und Komponenten Teil 1: Begriffe This European Standard was approved by CENELEC on 2001-12-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any
11、 alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made
12、 by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany
13、, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.EN 50324-1:2002 2 Foreword This European Standard was prepared by the CENELEC BTTF 63-2, Advanced technical ceramics. The text of the draft was submitted to the formal v
14、ote and was approved by CENELEC as EN 50324-1 on 2001-12-01. The following dates were fixed: latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2002-12-01 latest date by which the national standards conflicting
15、 with the EN have to be withdrawn (dow) 2004-12-01 This draft European Standard consists of three parts: Part 1 Terms and definitions Part 2 Methods of measurement - Low power Part 3 Methods of measurement - High power _ 3 EN 50324-1:2002 Contents Page Introduction.4 1 Scope 5 2 Normative references
16、 .5 3 Definitions.5 3.1 Ferroelectricity of ceramics5 3.2 Piezoelectricity of ceramics7 3.2.1 Piezoelectricity.7 3.2.2 Resonant vibration modes7 3.2.3 Stability .10 3.3 Classification of materials - Groups of piezoceramics.10EN 50324-1:2002 4 Introduction The principles underlying the piezoelectrici
17、ty of ceramics are discussed in IEC 60483 “Guide to dynamic measurements of piezoelectric ceramics with high electromechanical coupling”. Piezoelectric ceramics are polycrystalline ferroelectrics mainly based on lead zirconate titanate (Pb(ZrTi)O 3 ), barium titanate (BaTiO 3 ) and lead titanate (Pb
18、TiO 3 ). Their piezoelectricity is the result of the preferential orientation of polar regions at remanent polarisation. In ceramics, the remanent polarisation is created by application of a dc electric field to the polycrystalline material. The value of this remanent polarisation results in the hig
19、h level of piezoelectric activity in piezoceramics. Both the direct and inverse piezoelectric effects are utilized. In a variety of applications, piezoelectric transducers operate at resonance. Static and quasi-static applications complete a wide range of functions. 5 EN 50324-1:2002 1 Scope This Eu
20、ropean Standard relates to piezoelectric transducer ceramics for application both as transmitters and receivers in electroacoustics and ultrasonics over a wide frequency range. They are used for generation and transmission of acoustic signals, for achievement of ultrasonic effects, for transmission
21、of signals in communication electronics, for sensors and actuators and for generation of high voltages in ignition devices. Piezoelectric ceramics can be manufactured in a wide variety of shapes and sizes. Commonly used shapes include discs, rectangular plates, bars, tubes, cylinders and hemispheres
22、 as well as bending elements (circular and rectangular), sandwiches and monolithic multilayers. Relevant sections of IEC 60302 “Standard definitions and methods of measurement for piezoelectric vibrators operating over the frequency range up to 30 MHz” and IEC 60642 “Piezoelectric ceramic resonators
23、 and resonator units for frequency control and selection” have been taken into consideration when drafting this standard. 2 Normative references This European Standard incorporates, by dated or undated reference, provisions from other publications. These normative references are cited at the appropr
24、iate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references, the latest edition of the publica
25、tion referred to applies (including amendments). IEC 60302 Standard definitions and methods of measurement for piezoelectric vibrators operating over the frequency range up to 30 MHz IEC 60483 Guide to dynamic measurements of piezoelectric ceramics with high electromechanical coupling IEC 60642 Piez
26、oelectric ceramic resonators and resonator units for frequency control and selection - Chapter I: Standard values and conditions - Chapter II: Measuring and test conditions 3 Definitions The fundamental parameters of the equivalent electric circuit of a piezoelectric resonator are defined in IEC 603
27、02 and, additionally, IEC 60642 defines terms commonly used to characterize piezoelectrics. The additional terms defined in this standard describe the properties and performance parameters of piezoelectric ceramics. 3.1 Ferroelectricity of ceramics 3.1.1 ferroelectric ceramic non-linear spontaneousl
28、y polarised ceramics, generally with a high level of permittivity, exhibit hysteresis in the variation of the dielectric polarization as a function of electric field strength and temperature dependence of the permittivity (see “Curie temperature”). Ferroelectric ceramics become piezoelectric by the
29、induced alignment of dipoles, a process generally referred to as poling To create the macroscopic piezoelectric effect, the polar axes of dipole regions (domains) in crystallites of ferroelectric ceramics must be aligned. This requires the application of a high dc field at determined conditions of t
30、emperature and time. The poled ceramic has a remanent polarization P r which is necessary for piezoelectric activity.EN 50324-1:2002 6 3.1.2 anisotropy Figure 1 defines the crystallographic axes, as described for the elasto-piezoelectric-dielectric-matrix in IEC 60483, Table 1. The dielectric, elast
31、ic, and piezoelectric properties of poled ferroelectric ceramics depend on the direction of excitation and piezoelectric action with respect to the direction of remanent polarization 3.1.3 Curie temperature C this temperature corresponds to the maximum permittivity of ferroelectric ceramics. Ceramic
32、s are not piezoelectric above the Curie temperature 3.1.4 permittivity ij T ; ij S after poling dielectric anisotropy is present (see Figure 1) and the permittivity may be: “free” permittivity ij Tmeasured well below resonant frequencies; or “clamped” permittivity ij Smeasured far above resonant fre
33、quencies 3.1.5 (relative) dielectric permittivity, ratio of (absolute) permittivity ijto the permittivity of free space 0= 8,854 10 -12F/m, 3r T= 33 T / 0; 1r T= 11 T / 0 3.1.6 dielectric dissipation factor tan ratio of resistive power (dielectric power loss) to reactive wattless power at sine-wave
34、voltage of determined frequency; for piezoceramics measured well below the lowest resonant frequency usually at 1 kHz, together with free capacitance 3.1.7 free capacitance C T capacitance of a piezoelectric device, measured well below the lowest resonant frequency (see “free” permittivity) usually
35、at 1 kHz 3.1.8 clamped capacitance C S capacitance of a piezoelectric device, measured far above the resonant frequency (see “clamped” permittivity) 3.1.9 poling procedure for creating a macroscopic piezoelectric effect by aligning the polar axes of dipole regions (domains) in crystallites of ferroe
36、lectric ceramic under high electric dc field. The poled ceramic has a remanent polarisation needed for piezoelectricity 3.1.10 remanent polarisation P r macroscopic dipole moment of ferroelectric ceramic after poling 7 EN 50324-1:2002 3.2 Piezoelectricity of ceramics 3.2.1 Piezoelectricity Piezoelec
37、tricity can be understood as the coupling of elastic and dielectric properties of a solid exhibiting linear dependence of either - a mechanical load generating a charge, dependent upon the magnitude and direction of the load (direct piezoelectric effect), or - an electric field generating a deformat
38、ion, dependent upon the strength and direction of the electric field (inverse piezoelectric effect). 3.2.1.1 electromechanical coupling factor k defined by the square root of the ratio of the mutual elasto-dielectric energy density squared to the product of the stored elastic and dielectric energy d
39、ensities; defined for different boundary conditions, and a combination of elastic, dielectric, and piezoelectric constants. See also (material) coupling factors for different vibration modes and effective coupling factors respectively 3.2.1.2 piezoelectric charge constant d ij also: piezoelectric de
40、formation constant couples the electric displacement with the mechanical stress and the strain with the electric field strength respectively. For piezoceramics there are three constants d 33 , d 31 , d 15independent of each other 3.2.1.3 piezoelectric voltage constant g ij also: strain constant coup
41、les the electric field strength with the mechanical stress and the strain with the electric displacement. For piezoceramics there are three constants g 33,g 31 , g 15independent of each other 3.2.1.4 piezoelectric component one or more piezoelectric parts made from poled ferroelectric ceramic (piezo
42、ceramic), used for mechano-electrical or electro-mechanical conversion of energy or for signal processing 3.2.1.5 piezoelectric transducer piezoelectric part made from poled ferroelectric ceramic (piezoceramic), used for mechano-electrical or electro-mechanical conversion of energy. In the case of e
43、lectro-mechanical conversion of energy (see inverse piezoelectric effect) the piezoelectric solid will be excited to forced vibrations or to self- excited (resonant) vibrations (see vibration modes) 3.2.2 Resonant vibration modes 3.2.2.1 fundamental vibration mode (see Figure 2) vibration at the low
44、est resonance frequency of a given vibration mode 3.2.2.2 overtone vibration (resonance) excited above the fundamental vibration of a given vibration modeEN 50324-1:2002 8 3.2.2.3 thickness vibration (see Figure 2c) appears in thin, axially poled, piezoceramic plates with lateral dimensions much lar
45、ger than those in the vibration direction. In the case of thickness vibrations all deformations perpendicular to the vibration direction are zero (see stiffened vibration mode) 3.2.2.4 thickness coupling factor k t static electromechanical coupling factor of the thickness extension vibration 3.2.2.5
46、 radial vibration (see Figure 2b) vibration mode of a thin piezoceramic disc (planar vibration, see planar coupling factor) or of a thin piezoceramic ring 3.2.2.6 planar coupling factor k p electromechanical coupling factor of fundamental radial vibration of a thin piezoceramic disc with axially pol
47、ar axis (two-dimensional isotropy) 3.2.2.7 transverse length vibration (see Figure 2a) appears at slim piezoceramic bars with electrodes perpendicular to the poling direction 3.2.2.8 transverse coupling factor k 31 static electromechanical coupling factor of the transverse length vibration 3.2.2.9 t
48、hickness shear vibration (see Figure 2e) appears in ferroelectric ceramics poled perpendicularly to the direction of the exciting field parallel to the thickness 3.2.2.10 thickness shear coupling factor k 15 static electromechanical coupling factor of the thickness shear vibration 3.2.2.11 longitudi
49、nal length vibration (see Figure 2d) appears in axial poled piezoceramic excited in the direction of poling 3.2.2.12 longitudinal coupling factor k 33 static electromechanical coupling factor of longitudinal length mode of vibration 3.2.2.13 piezoelectric unstiffened vibration mode in an ideally unstiffened vibration mode, the electric field is transverse to the direction of the elastic wave motion. The radial vibration and the tran
