S. Berliner, III's berliner-ultrasonics.org Ultrasonics Page 7 keywords = " ultrasonic ultrasound cavitat ultraschall sonde ultrasonique sonotrode acoustic sonic sound wave ultra liquid processing Ultrasonic Industry Association UIA bubble shock wave clean immersi vapor degreas weld join bond sew seal solder insert stak drill grind machin cut extru form spin sonochemi react accelerat pollut abat toxi waste treat beneficiat remediat particl dispers disrupt homogeniz emulsif dissol degas foam defoam sparg phaco phaeco lithotript liposuct prophyla history Narda microwave fusion propulsi fluid filtration home.att.net "
Updated:  06 Mar 2010, 15:00  ET
    [Created 25 Oct 2005;
original AT&T Worldnet Website begun 30 May 1996.]

Update info on the top on ALL pages for your convenience.
URL http://berliner-ultrasonics.org/uson-7.html
(formerly http://home.att.net/~Berliner-Ultrasonics/uson-7.html 
moved to this domain on 06 Mar 2010)

S. Berliner, III
Consultant in Ultrasonic Processing
"changing materials with high-intensity sound"


also see
Keywords (Applications) Index

[consultation is on a fee basis]

Specializing in brainstorming and devil's disciplery for new products and
reverse engineering and product improvement for existing products.


Technical and Historical Writer, Oral Historian
Popularizer of Science and Technology  

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Ultrasonics Page 7


PLEASE NOTE:  If some internal links refuse to work,
please click on Back and scroll down.

Ultrasonics Index

On the main Ultrasonics Page:
    Applications List.
    Probe-type Ultrasonic Processing Equipment.
    Quick Links to Major Ultrasonic Probe Manufacturers (moved to this page 10 Jul 2002).
    Brain Storming - bright ideas, pipe dreams, pie-in-the-sky?

On Ultrasonics Page A
        (A Layperson's Explanation of a Complex Letterhead).

On Ultrasonics Page 1:
        (A Non-Technical Explanation of "Cold Boiling"
            moved from the preceding page 12 Feb 00).
    TUBULAR HORNS (Radial Radiators).
    CARE of TIPS (Radiating Faces).

On Ultrasonics Page 1A:
    Free Bubbling.
    Bubble Entrapment.
    Foaming and Aerosoling - moved 28 May 02 to this Page 4.
    Call for Contributions for Book.

On Ultrasonics Page 2 (the next page):
    More on Cavitation.

On Ultrasonics Page 3:
    Keywords (Applications) Index.
    What's New?

On Ultrasonics Page 4:
    Foaming and Aerosoling - moved 28 May 02 from Page 1A.
    Ultrasonic Propulsion (Propulsive Force) - Moving Material.
    Ultrasonic Fountains - Atomization, Nebulization, Humidification,
        Misting, Particle Creation and Sizing.
    Ultrasonics and Nuclear Fusion.
    Boosters (Booster Horns).
    Quick Links to Major Ultrasonic Probe Manufacturers (moved to this page 10 Jul 2002).

On Ultrasonics Page 5:
    Ultrasonic Whistles (Nozzles, Atomizers, Nebulizers).
    AM-9 - The Use of Ultrasonic Probes in Fuel Research.

On Ultrasonics Page 6:
    Flow Through Horns.
    Explosion Resistance.
    ULTRASOUND - Sonar, Imaging, NDI/NDE, and HIFU.
    Quacks and Failures in Ultrasonics.

On Ultrasonics Page 7 (this page):

On the Ultrasonic Cleaning Page:
    Ultrasonic Cleaning {in process}.
    Immersible Transducers.
    What's New?

    ULTRASONICS GLOSSARY {in process}.

    Ultrasonic Bibliography Page 1 - Reference Books on Acoustics,
        Vibration, and Sound.
    Ultrasonic Bibliography Page 2 - Sonochemistry.
    Ultrasonic Bibliography Page 3 - Selected Articles.

You are invited to visit the ULTRASONIC INDUSTRY ASSOCIATION home page.

CALL FOR CONTRIBUTIONS:  I am writing a book on "High-Intensity Ultrasonic Technology and Applications", on the practical application of power (high intensity) ultrasonics, the use of ultrasonic energy to change materials.  Contributions are welcome (see below).


Larry Crum's Cavitation Bubble

[image from University of Washington, Applied Physics Laboratory (Lawrence Crum, Ph.D.)
- bubble diameter approximately 1mm]




[Partially updated 25 Oct 2005 (for currency) and based on
SONICATOR® SERIES TECHNICAL NOTE TN-2 of the same title of Oct 1988]


Ultrasonic liquid processors are normally furnished with tapped disruptor horns having replaceable flat titanium tips.  Normal sonication produces cavitation in liquids, the formation and collapse of microscopic vapor bubbles, generating shock waves which radiate outward and disrupt cells, homogenize and emulsify samples, degas liquids, etc.  Shock waves, being radially symmetrical, attack the acoustic radiating surface of the tip or horn as well as the sample.  The erosion which results reduces the efficiency of sonication in direct proportion to the degree of erosion.  Certain solvents have been found to wick under replaceable flat tips and cause deterioration and early failure.  Solid horns are thus recommended in lieu of tapped horns for such applications.  The output at the tip of a solid horn being the same as on the replaceable flat tip of a tapped horn, this would be an excellent solution but for the price of solid horns.  Solid horns can be dressed as erosion proceeds but, once the erosion becomes excessive, a solid horn can only be scrapped or converted to a tapped horn.  Titanium is used extensively in military aerospace hardware and has become relatively expensive.  Thus, using solid horns as disposables is somewhat less than desirable.

For cases where the horn and tip configuration is such that the tip can not reach far enough into a processing vessel, 5" long "Half Wave" Extender Tips are available.  For even longer-reach applications, 10" (25.4 cm) long "Full Wave" Extender Tips can be furnished.  However, solid extender tips are less expensive than solid horns and thus are also recommended as a lower-cost disposable alternative.

[Please note - for purposes of convenience, the author uses herein
the terminology he established for Heat Systems (now Misonix) Inc.
Other manufacturers may use somewhat different terms.]


Half Wave Extender Tips are simple cylinders, nominally 5" long (12.7cm, one half wavelength of sound at 20kHz in titanium alloy), with a connecting stud at the horn end and either solid or tapped (with a replaceable tip) at the output end.  The stud fits directly into the threaded end of tapped disruptor horns and, in effect, simply moves the radiating face 5" (12.7 cm) further away from the convertor {at 20KHz}.

Certain protocols, such as older versions of the EPA Contract Laboratory Program for Analysis of Semi-Volatile Wastes and Pesticides and the EPA SW-846 Method 3550 for Analysis of Solid Wastes, required an ultrasonic liquid processor with a ½" (1.91 cm) Standard Solid Horn.  The ¾" Standard Solid Horn gives moderate intensity cavitation, as opposed to the ¾" High Gain ("Q") Disruptor Horn, which gives very high intensity sonication.  Use of the Standard ¾" Tapped or Solid Horns at the same output control knob settings or the ¾" High Gain Q-Horn at half those settings yields identical results.

Further, methylene chloride and other thin solvents, used for extraction in many protocols, were found to wick under replaceable ¾" and 1" flat tips and cause early failure.  For this reason, use of the ¾" Solid Disruptor Horn in lieu of the ¾" Tapped Disruptor Horn was recommended for EPA use.  An alternate would be to use the ¾" Solid High Gain ("Q") Disruptor Horn instead of the ¾" Tapped High Gain Q-Horn.  Since the output at the tip of solid horns is the same as on the replaceable flat tip of tapped horns of like configuration, similar substitutions apply in other disciplines.  Another related problem occurs in sonicating liquids containing suspended abrasive fine particles, such as aluminum oxide or tungsten carbide; such fines are carried between the tip and horn and grind away both mating surfaces.  The result is eventual loss of the horn, as well as the tip.

Many customers like to work in flasks, for which a special ¾" horn and the ¾" Tapped Half Wave Extender Tip were recommended for EPA work.  Again, the output amplitude (and thus intensity) at the ¾" Flat Tip is the same whether it is on the ¾" Standard Tapped Horn or on the ¾" Extender (in turn mounted on the special ¾" horn).  Because of the high cost of the special ¾" horn, the ¾" half wave extender tip system was redesigned.  The original ¾" Solid Horn and Tapped ¾" Half Wave Extender Tips were superseded by newer Tapped ¾" Half Wave Extender Tips which fit the Standard ¾" Tapped Horn.  The latter two newer tips fit directly on either the Standard or the High Gain "Q" ¾" Tapped Disruptor Horns.  To further offset high costs, greatly reduced prices are offered for solid extender tips bought in moderate quantities.

[NOTE - The old {as of 1995} ¾" Extender Tips can NOT be used on the new Standard or High Gain "Q" Tapped Horns.  Similarly, the new Half Wave Extender Tips can NOT be used on the old Special Horn.  For those customers who have already invested in old Extender Tips and the Special Horn and do not wish to change over, the old extenders will continue to be supplied (by Misonix).]

For longer-reach applications, ½" (1.27 cm) and ¾" (1.91 cm) "Full Wave" Extender Tips can also be furnished.  These tips are simple cylinders, nominally 10" long (25.4 cm, one full wavelength of sound at 20kHz in titanium alloy), with a stud at the horn end and either solid or tapped (with a replaceable tip) at the output end.  The stud fits directly into the threaded end of tapped disruptor horns and, in effect, simply moves the radiating face 10" (25.4 cm) further away from the convertor.  1" (2.54 cm) half and full wave extenders can be supplied on special order.

Half and full wave extenders put extremely high stress on the connecting stud, which may not survive extensive use at high output control settings.  Contact the factory for such special applications.  Disclaimers in current processor instruction manuals may be disregarded, provided that three conditions apply.  First, the factory must agree.  Second, the connecting stud MUST be a new stainless steel stud (not an old black alloy steel stud).  Third, the temperature of the horn/extender joint must be routinely monitored (with power OFF!); any temperature more than just comfortably warm requires that power be turned off and the joint disassembled for cleaning and inspection.

horn system
(illustration by S. Berliner, III - scope expanded 10 Dec 05 - all rights reserved)


To minimize sample contamination by erosion products and further reduce overall project costs, the author developed a bonded sapphire tip for solid horns.  A thin disc of clear, single-crystal, boule-grown, synthetic sapphire is bonded to a solid horn with an epoxy of extremely high shear strength.  Sapphire (corundum, alumina, aluminum oxide) has a hardness of 9 on the Mohs scale where diamond# is 10.  Tests have shown that sapphire surfaces last approximately 10 times longer than titanium alloy under like conditions.  Although very expensive initially, the sapphire tipped horns avoid the need for some nine changes of tapped tips and associated downtime and labor.  It is suggested that three sapphire tipped horns be rotated in use for critical processes; one on line, one on standby, and the third available for refacing at the factory.  There are three standard sizes of sapphire tipped horns (½", ¾", and 1").

Sapphire discs can not be used on replaceable flat tips because the forces generated in wrenching the tips on and off crack the disc.  Thicker tips can not be used because the joint then moves further toward the highest strain area of the horn (the nodal point) and the joint will fail.  To further reduce overall costs, the author recommends that sapphire tipped extenders be considered.  Sapphire tips can be fitted to solid extenders for the same additional cost as for their fitting to solid horns.

# - Diamond can not be used as a facing because it is pure carbon and will oxidize (burn) away instantly (an expensive mistake!); sapphire, being aluminum oxide, is already reduced (inert).


One of the problems encountered early on in the development of the modern ultrasonic cell disruptor and liquid processor was noted earlier in this work.  There is a tendency for water and certain solvents to wick under replaceable 1" and ¾" (and even ½") flat tips, and of abrasive fines to enter with the liquid, and cause early failure.  The tendency is more marked in the larger diameters because of the "cantilevering" effect; as the tip is pulled back in the deceleration mode, the center moves faster than the rim due to inertia and plastic deformation at 20kHz (or higher).  This leaves the underside of rim slightly pulled away from the circumferential edge of the horn and the contaminants enter the annulus thus opened.  In the acceleration mode, the rim slams back against the horn, trapping and grinding any solid contaminants against both mating faces and cavitating the liquid between the faces.  These two actions rapidly cause deterioration of the tip and horn.

A similar cantilevering effect causes early failure of improperly bonded sapphire disks.  If the epoxy bond line is too thick, the disk "wallows" in the flexible adhesive and fails in a circumferential fracture line, approximately 1/3-radius in from the edge.  On the other hand, a rigid bond will fail because the base metal of the horn (titanium alloy) is elastic.

Coatings such as flame depositions or platings spall off within seconds at high amplitude as the cavitation process unerringly picks the molecular weak spots in the coating and drills through and under.

The author has personally seen the finest technical chromium plating break up while he watched, much as the most highly-touted ceramic facing vanished in moments.  Sintered carbides and sapphire disintegrated in seconds as cavitation occurring at the surface and between the grains broke apart the grain bonds.

To prolong the life of any titanium tip, be it a replaceable flat tip, a microtip, or a solid horn or extender, a reasonable amount of polishing on fine crocus cloth or emery paper may be done.  The limitation is the inability of the unit to be tuned if too much material is removed.  Polishing should be done as soon as the radiating surface becomes roughened (matte finish).  Since the erosion results as cavitation works into the dendritic structure of the base metal, the longer one waits before polishing, the deeper the pitting gets and the less effective any subsequent polishing becomes.  This polishing can not be done well by hand without a jig or fixture to hold the radiating face parallel to the abrasive material.  It can NOT be stressed enough that machining or grinding is too drastic a remedy.

The author recommends always having at least three tips available; one on line, one reserved for replacement, and one being refinished.

S. Berliner, III - © 2005, 1995, 1992, 1988 - (all rights reserved)

[It is my intention to revise the above AL-5 with more illustrations than were present in the last revision or in the original TN-2 and to link appropriate other sections of this website.]

- - - * - - -

The original TN-2 (of Oct 1988) also included ordering numbers for Heat Systems (Misonix) horns and tips; it is reproduced here for the convenience of those individuals who can follow the old part numbers; the author makes no representation whatsoever that the numbers are current nor that the items are still available:

- - - * - - -

TIP DIA:		½"		¾"		1"


		201S		208S		209S


		200		207		210


TAPPED	406HW050T		406HW077T		406HW100T*

SOLID	406HW050		406HW077		406HW100*

SAPPHIRE	406HW050S		406HW077S		406HW100S*


TAPPED	406FW050T		406FW077T		406FW100T*

SOLID	406FW050		406FW077		406FW100*

SAPPHIRE	406FW050S		406FW077S		406FW100S*

* - Non-standard; special order only


Ultrasonic energy should, on the face of it (awful pun), be quite useful for deburring machined parts and it has been used successfully in such applications on occasion.  The problem, and the reason such a use is not better known, is that the very action which removes the burrs also degrades the machined surfaces.  Long, narrow burrs, lightly attached, are readily knocked loose and the remanent stub polished over by cavitation impacts but short stubby burrs, wider at the base and strongly attached, are no more affected than the machined surfaces from which they protrude:

(22 Sep 06 illustration by S. Berliner, III - all rights reserved)

Addition of a fine abrasive slurry to the cleaning bath can greatly facilitate burr removal but may also degrade both the work surface and the radiating face of the tip/horn.

Thus, only very unique situations are amenable to ultrasonic deburring; contact the author for individual solutions.

You may wish to visit the main ULTRASONICS page, et seq., with more on ultrasonics, as well as the Ultrasonics Cleaning page {in process} and the Ultrasonics Glossary page {also in process}.

Those persons interested in SONOCHEMISTRY might wish to look at the sonochemistry pages of:

    Prof. Kenneth S. Suslick of the University of Illinois at Urbana-Champaign, and

    Dr. Takahide Kimura at Shiga University in Japan.

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To tour the Ultrasonics pages in sequence, the arrows take you from the main Ultrasonics Page (with full index) to Pages A, 1, 1A, 2, 3, 4, 5, 6, and this page 7, Glossary Page, Cleaning Page, and Bibliography Pages 1, 2, 3, and 4 (see Index).

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