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Influence of the Chemical Composition on the Physical Properties of Pzt-Type Piezoceramic Transducers.

100%

Surowiak Z. , Czekaj D. , Fesenko E. , Razumovskaya O. , Reznichenko L. , Zakharchenko I.

2003

tom Vol. 24

183-209

Result if investigations on influence of lead deficiency on the crystalline structure of PZT-type ceramic piezoelectric materials is presented. The solid solution of (x)PbTiO3-(1-x-y)PbZrO3-(y)SigmaPb(B'1-alfaB"alfa)O3, exhibiting the perovskite-type structure, condtitutes the basis of such materials. The lead deficiency was originated by a thermal treatment. Investigations on influence of lead deficiency on the crystalline structure of PZT-type ceramics have been performed for solid solutions exhibiting the chemical compositions corresponding to the tetragonal or rhombohedral boundary of the morphotropic region (PCR-1, PCR-8: "Piezoelectric Ceramics of Rostov") and to tetragonal phase region compositions (ceramics of Pb(Zr0.39Ti0.59W0.01Cd0.01)O3). It has been found that the deficiency in lead causes a change of the point group or a change of the space group of the perovskite phase crystalline structure of PZT. The solid solutions on the basis of Pb(Zr,Ti)O3 partly resolve themselves into PbTiO3, ZrO2 and (PbO) when the lead deficiency caused by thermal treatment increases.

Crack arrest saturation model under combined electrical and mechanical loadings

84%

Bhargava R. R. , Setia A.

2009

tom Vol. 37, nr 2

544-548

Purpose: The investigation aims at proposing a model for cracked piezoelectric strip which is capable to arrest the crack. Design/methodology/approach: Under the combined effect of electrical and mechanical loadings applied at the edges of the strip, the developed saturation zone is produced at each tip of the crack. To arrest further opening of the crack, the rims of the developed saturation zones are subjected to in-plane cohesive, normal uniform constant saturation point electrical displacement. The problem is solved using Fourier integral transform method which reduces the problem to the solution of Fredholm integral equation of the second kind. This integral equation in turn is solved numerically. Findings: The expressions are derived for different intensity factors and energy release rate. A qualitative analysis of the parameters affecting the arrest of opening of the crack and fatigue crack growth with respect to strip thickness and material constants are presented graphically. Research limitations/implications: The investigations are carried out by considering the material electrical brittle. Consequently, the zones protrude along the straight lines ahead of the crack tips. And further, the small scale electrical yielding conditions are used. Practical implications: Piezoelectric materials are widely getting used nowadays, even in day to day life like piezoelectric cigarette lighter, children toys etc. And, its advance used in technology like transducers, actuators has been already in progress. So, the aspect of cracking of piezoelectric materials are of great practical importance. Originality/value: The piezoelectric material under the combined effect of electrical and mechanical loadings gives the assessment of electrical displacement which is required to arrest the crack. The various useful interpretations are also drawn from the graphs.