Ultrasonic machining

A high frequency generator triggers a piezoceramic sonic modifier. The sonic modifier oscillates with the frequency of stimulation (normally around 20 kHz) at a low amplitude of around 5 pm. The amplitude of the ultrasound can be amplified by coupling the sonic modifier with a transformer and sonotrode. These elements are tuned to the frequency and the amplitude intensified to 20-40 pm. The sonotrode also acts as locator for the tool [281,282]. The tool is joined with the sonotrode by brazing, sticking or press-bonding. 

A movement in 2-axis determines the feed rate. The suspended abrasive particles are accelerated by the longitudinal movement of the tool in the 

The process to create certain features in a workpiece can be optimised by the appropriate choice of the abrasive particles [289]. The ultrasonic machining process can be performed using a constant feed rate or a constant force. Fine geometrical features can be best fabricated using constant small feed rates because of the minimal forces allowed for optimised shaping conditions. 

Two types of ultrasonic machining are currently used ultrasonic sink and ultrasonic path machining. In the case of sink machining the ablation rate is highest in front of the tool. At the sides of the tool the ultrasonic amplitude in normal direction to the surface is rather small, which results in a rolling of the abrasive particles so that the particles cause no direct impact in the work piece. A review of ultrasonic machining can be found in the literature [517]. 

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Electrical discharge machining Electrochemical milling Electron beam machining Laser beam machining Ultrasonic machining... 

A number of applications of power ultrasound are to be found in heavy industry both in metalworking and processing [17]. The machining of modem materials requires tools that can deal with unusual properties, complex shapes of work-pieces, and accuracy in working. Basic ultrasonic machining processes become of importance when dealing with carbides, stainless steels, ceramics and glass. Four main types of application are of industrial relevance ... 

Ultrasonic machining, also known as ultrasonic impact grinding, uses ultra-sonically induced vibration delivered to a tool to create accurate cavities and channels of many shapes [146]. It can be used to form deep cavities as small as 250 pm in diameter (with an accuracy of 50 pm) in both hard and brittle materials such as glass, quartz, polymers, ceramics and metals. This technique may be useful for fabrication of large masters. 

Study of 3D micro-ultrasonic machining. Journal of Manufacturing Science Engineering, Transactions of the ASME, 126, 727-732. 

Ultrasonic machining (USM) is also of particular importance when very hard type materials are to be cut. As an assist to drilling, HDM energy can extend the drill life when producing holes in reinforced plastics. If the plastic is conductive, electrical discharge machining (EDM) or electrochemical machining (ECM) may be useful. 

Uarco, Inc., 1713 U charts, 1844, 1847-1849, 1851 UILS, see Universeil indirect labor standards Ultrasonic detection, 1614-1615 Ultrasonic machining, 1323 Ultrasound sensors, 385, 386 UML, see Unified Modeling Language UMTRCA (Uranium Mill Tailings Radiation Control Act), 1153 Uncertainty interval of, 2548 optimization under, 2625-2628 Uncertainty avoidance (in national cultures), 957, 958, 960... 

Ultrasonic machining (USM) is a method in which a tool called sonotrode and free abrasives are used. The sonotrode vibrates at a very high frequency of about 20 to 40 KHz and drives the abrasive to create a brittle breakage on the workpiece surface. Since material removal is based on the brittle breakage, this... 

Compared to other micromachining processes such as micro-EDM, micro-USM (Ultrasonic machining), micro-LBM (laser beam machining), and tool-based micromachining, the initial setup as well as mnning cost of EMM is lesser. 

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