The paper details the effects of depth of cut and vibration amplitude when ultrasonic assisted (US) creep feed grinding Inconel 718 with an open structured alumina based wheel. The workpiece was actuated at a constant frequency (~20.5kHz) via a block sonotrode attached to a 1kW piezoelectric transducer-generator system. A full factorial experimental array comprising 12 tests was conducted invol...

Single point incremental forming is used for rapid prototyping of sheet metal parts. This forming technology was applied to the fabrication of thin shell micropyramids of aluminum, stainless steel, and titanium foils. A single point tool used had a tip radius of 0.1 mm or 0.01 mm. An ultrasonic spindle with axial vibration was implemented for improving the shape accuracy of micropyramids formed...

introduction: the aim of this experimental laboratory study was to evaluate the effect of different mixing and placement techniques on compressive strength (cs) of calcium-enriched mixture (cem) cement. methods and materials: cem powder was mixed with its liquid either by hand mixing or amalgamator mixing. the mixture was loaded to cylindrical acrylic molds with 6.0±0.1 mm height and 4.0±1 mm d...

PURPOSE To compare patients' perception of discomfort, vibration and noise levels between piezoelectric and the magnetostrictive ultrasonic units during periodontal debridement. METHODS Periodontal debridement was performed on 75 subjects using a split-mouth design. Two quadrants on the same side were instrumented with a piezoelectric ultrasonic device (EMS Swiss Mini Master® Piezon) and the ...

We are developing a new method using ultrasonic longitudinal and torsional vibration of a hollow-type stepped horn for hole machining. We foresee that the equipment can be simplified and miniaturized. In this paper, ultrasonic vibration sources of a hollow-type stepped horn without a diagonal slits vibration converter and with a diagonal slits vibration converter are used. The longitudinal and ...

We report the results of nuclear magnetic resonance imaging experiments on granular beds of mustard grains fluidized by vertical vibration at ultrasonic frequencies. The variation of both granular temperature and packing fraction with height was measured within the three-dimensional cell for a range of vibration frequencies, amplitudes and numbers of grains. Small increases in vibration frequen...

one of the great challenges in the processing of materials using equal channel angular pressing (ecap) is the high forming forces required to produce large shear deformation in the material. researchers show that the friction forces between the die and the sample constitute a great part of the total forming forces. recently, ultrasonic vibrations are successfully implemented into the ecap proce...

The purpose of this study was to determine the effect of ultrasonic vibration on the force required to remove prefabricated posts. Ninety-six extracted human canines were divided into eight groups, which were prepared and obturated with gutta-percha and either a eugenol-containing (Roth's 801 Elite) or eugenol-free (AH26) sealer. Titanium #6 Parapost XH posts were cemented with either zinc phos...

In Electrical Discharge Machining, oxides (or debris) are created and accumulated in the sparking gap between an electrode and a work piece. If the debris density becomes too great in certain points in the gap, there is a reduction in the resistance, which encourages the formation of abnormal discharges, results in significant electrode damage and slows down the material removal rate. To enhanc...

This in vitro study compared different ultrasonic vibration modes for intraradicular cast post removal. The crowns of 24 maxillary canines were removed, the roots were embedded in acrylic resin blocks, and the canals were treated endodontically. The post holes were prepared and root canal impressions were taken with self-cured resin acrylic. After casting, the posts were cemented with zinc phos...