Electrowave Ultrasonics Corporation
Electrostrictive vs Magnetostrictive

 

A transducer is a device which converts electrical energy into mechanical energy. In an ultrasonic system, the transducer takes the electrical energy from the generator and converts it to mechanical energy which is transmitted into the fluid. At ELECTROWAVE ULTRASONICS CORPORATION we utilize two basic classes of transducers in our systems, these are the electrostrictive (piezoelectric) type and the magnetostrictive (nickel plate) type. The method of generating ultrasonic energy is not significant in determining its ability to produce cavitation in a given fluid. A magnetostrictive transducer can convert the same frequency and power as an electrostrictive transducer although more input power (~2x) may be required for equal intensity in magnetostrictive systems. To list all electrostrictive and/or magnetostrictive transducers together as similar in performance and reliability is a serious error, and there is a considerable difference between ELECTROWAVE and any other ultrasonics manufacturer.

ELECTROSTRICTIVE (Piezoelectric) SYNCROPOWER
Construction: Lead Zirconate Titanate ceramic rings bolted between titanium or aluminum blocks (or drumhead mode). ELECTROWAVE is one of the few manufacturers that produces its own ceramic transducer, our SYNCROPOWER transducer has the highest power ratings in the world with a movement to millivolt rate (d33) exceeded by none. SYNCROPOWER transducers can be driven at watt densities of over 100 W sq. in., unfortunately liquids will not accept this type of power, and these higher watt densities are limited to production bonding of thermoplastics.
Voltage: High, 100V - 1000V RMS and higher.

Bond: Elements bolted in place, or permanently fixed with a thermoset ceramic composite (low-bake) exclusive to ELECTROWAVE. No epoxies, cyanoacrylates, or 'glues' of any type are used in ELECTROWAVE ultrasonics.

Performance: High performance, high efficiency type. Driven at 5W - 100W sq. in. of radiating surface, with a 98%+ efficiency in power to cavitation conversion. Automatically sweeps a frequency range of +-5% which changes the cavitational wavelengths and results in uniformly dispersed ultrasonic activity.
Available in EW, ES and SU series ultrasonic systems, frequencies 13KHz - IOOKHz (Higher upon request [pulsed-systems]). Please call for quote.

MAGNETOSTRICTIVE (Nickel Plate)
Construction: Nickel plates in an exclusive honeycomb configuration using direct current acting as a bias clamp (No permanent magnets). Open spaces are used to facilitate heat dissipation from a unique high surface-area grid.

Voltage: Low, 100V RMS or lower.

Bond: Vacuum brazed (stainless steel).

Performance: High performance - Driven at 10 W sq. in. (minimum) input power to produce cavitational intensifies equal to electrostrictive, although energy dispersion may not be as uniform due to cavitational stratification in the liquid layers caused by the narrow frequency band (<2%). Solvents with low boiling points may overheat in this type of system, and it is not fully suitable for portable equipment due to the additional weight (3x in some models).
Available in ES, and SU series ultrasonic systems, frequencies 20KHz - 25KHz (Higher upon request), Please call for quote.
  Unfortunately magnetostrictive materials are not widely used at this time because magnetostrictive metals are somewhat inefficient, and magnetostrictive ferrites are brittle. Over the years they have been replaced by electrostrictive ceramic transducers due to modem industrial requirements for high power and efficiency, in fact, over 90% of all ultrasonic systems that exist in the world today utilize some type of electrostrictive transducer. Most of our sales for the magnetostrictive types have come through contracts with the U.S. Navy for special units put into submarine use, and even their requirements for these systems are rapidly changing.

NOTE: Magnetostrictive systems utilizing permanent magnets must be avoided due to the high depolarization rate (2% per 500 hrs. operation) of these materials. Also, magnetostrictive ferrites should not be used because they are brittle and produce lower cavitational power than other magnetostrictive methods.
In contrast, ELECTROWAVE magnetostrictive metals will never depolarize and will last continuously for 10 to 20 years, as will our SYNCROPOWER electrostrictive (piezoelectric) transducers which have an age-loss logarithm [k33] of only 1.8% -3% per decade average for the first two decades, and an additional 1.8% - 3% after another one hundred years. However, beware of barium titanate cast ceramic transducers which are not recommended for heavy use and produce relatively weak cavitation intensity with a high age-loss rate, and a low Curie (depolarization) point. These inexpensive cast ceramic transducers are preferred by some manufacturers for use in table-top and small commercial ultrasonics.
  The main factor in the durability of either electrostrictive or magnetostrictive ultrasonics is cavitational erosion due to the fact that the cavitational intensity is so strong it will literally rip the steel from the tank surface. It is for this reason that very high grade (hard chrome) steels [316L] must be used in the construction of ultrasonic tanks. ELECTROWAVE warranties all its ultrasonic systems against cavitational erosion for ten years.   Regardless of which system type you choose, contact ELECTROWAVE and we will give you more in power, durability and reliability than anything you have ever seen before in ultrasonics.

  Electrowave Ultrasonics Corporation