PHYSICAL AND PIEZOELECTRIC PROPERTIES OF APC MATERIALS

- Apr 17, 2019-

APC Material:840841850854855860880
Navy Type EquivalentNavy I--Navy IINavy VNavy VIPorousNavy III
Relative Dielectric Constant
KT1275137519002750330012001050
Dielectric Dissipation Factor (Dielectric Loss(%)*
tan δ0.600.40≤ 2.00≤ 2.00≤ 2.50≤2.000.40
Curie Point (°C)**
Tc325320360250200360310
Electromechanical Coupling Factor
kp0.590.600.63.660.680.500.50
k330.720.680.72.680.760.450.62
k310.350.330.36-0.40-0.30
k150.700.670.68-0.66-0.55
Piezoelectric Charge Constant (10-12 C/N or 10-12 m/V)
d33290300400600630380215
-d31125109175260276-95
d15480450590625720-330
Piezoelectric Voltage Constant (10-3 Vm/N or 10-3 m2/C)
g3326.525.524.825.521.038.025.0
-g3111.010.512.4-9.0-10.0
g1538.035.036.0-27.0-28.0
Young's Modulus (1010 N/m2)
YE118.07.66.36.05.9-9.0
YE336.86.35.45.25.1-7.2
Frequency Constants (Hz*m or m/s)
NL (longitudinal)152417001500-1390-1725
NT (thickness)2005200520402000207913902110
NP (planar)2130205519801972192019002120
Density (g/cm3)
ρ7.67.67.67.67.66.67.6
Mechanical Quality Factor
Qm5001400807065501000
Acoustic Impedance (Mrayl)--31.5--16.5

 

APC Material:842844

851

881
Relative Dielectric Constant
KT13751500

1950

1030
Dielectric Dissipation Factor (Dielectric Loss(%)
tan δ0.450.40

1.50

0.40
Curie Point (°C)
Tc325320

360

310
Electromechanical Coupling Factor
kp0.650.68

0.71

0.58

kt

0.48

0.48

0.51

0.46

Piezoelectric Charge Constant (10-12 C/N or 10-12 m/V)
d33300300

400

220
Piezoelectric Voltage Constant (10-3 Vm/N or 10-3 m2/C)
g3326.324.5

24.8

26.7
Young's Modulus (1010 N/m2)
YE118.07.6

6.3

9.0
YE336.86.3

5.4

7.2
Frequency Constants (Hz*m or m/s)
NT (thickness)20502050

2040

2050
NP (planar)22302250

2080

2300
Density (g/cm3)
ρ7.67.7

7.6

7.6
Mechanical Quality Factor
Qm6001500

80

1000

The values listed above pertain to test specimens. They are for reference purposes only and cannot be applied unconditionally to other shapes and dimensions. In practice, piezoelectric materials show varying values depending on their thickness, actual shape, surface finish, shaping process and post-processing.

Note: measurements made 24 hours after polarization.
Maximum voltage:5-7 VAC /mil for 850, 851, 854, 855, Type VI VDC ~2X.
9-11 VAC /mil for 840, 841, 842, 844, 880, 881 VDC ~2X.

*At 1 kHz, low field.
**Maximum operating temperature = Curie point/2.

Standard Electrical Tolerances (Tighter tolerances avaliable on request)

- Capacitance: ±20%
- d33 Value: ±20%
- Frequency: ±5% (to ±0.5% on request)

Background on APC's Piezo Materials

Having a consistent piezoelectric material is important to the development and production of piezo devices. APC’s piezoelectric materials are known in the industry for their purity and low variability in mechanical and electrical properties. 

APC’s piezo materials fall into two broad categories: hard piezo material and soft piezo material. 

soft piezo material exhibits: larger piezoelectric constants, higher permittivity, larger dielectric constants, higher dielectric losses, larger electromechanical coupling factors, low mechanical quality factors, a lower coercive field, poor linearity, and is easier to depolarize. This combination of properties makes soft piezo materials ideal for many sensing applications. APC’s primary soft pizeo materials are APC 850, APC 854 and APC 855. 

hard piezo material exhibits: smaller piezoelectric constants, lower permittivity, smaller dielectric constants, lower dielectric losses, smaller electromechanical coupling factors, high mechanical quality factors, a higher coercive field, better linearity, and is harder to depolarize. This combination of properties makes hard piezo materials ideal for many high power applications. APC’s primary hard pizeo materials are APC 840, 841, and APC 880. 

APC’s 840, 841, 850, 854, 855, and 880 piezo materials are all proudly manufactured in the United States of America.

APC's piezoelectric ceramics are generally manufactured from PZT (Pb - lead, Zr - zirconium, Ti - titanium). This compound class shows much better piezo-electrical and piezo-mechanical efficiency than naturally occurring piezoelectric materials such as quartz.

The PZT- formulation can be varied with a variety of dopants allowing for a broad spectrum of material properties optimized for different application profiles.

Unfortunately, not all desirable properties can be put into a distinct piezo compound. Piezo-mechanics is to some extent is an "art of compromise", when selecting a suitable material for a distinct application.

Developing new piezo-materials is a steadily ongoing process in the ceramic industry. PZT is the most widely used smart material for solid-state actuation. Alternative materials with enhanced strain capability are under study, but all these "innovative" materials have drawbacks regarding common driving conditions.

PZT ceramics' material data are usually defined at low field excitation where nonlinearities are not dominant. In practice, high electrical fields are applied often applied resulting in a nonlinear enhanced response ("ferro-effects") and altered parameters. Nevertheless, for reasons of comparison with materials from different suppliers, the classical characterizations are used for describing piezoelectric ceramics. The data shown in the tables are valid for room temperature operation.

Piezoelectric ceramics are a ferroelectric compound. This means, that the electro-mechanical conversion process for producing a motion is related a kind of self-enhancement process based on an internal reorganization of the material's structure. This self-enhancement process results in the higher piezo-electrical efficiency of PZT when compared to natural materials like quartz.