Ultrasonic machining ceramic materials

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. 

Spur, G. Krieg, G.H. The influence of machine tool materials on the wear of profile tools in ultrasonic fine lapping of reinforced high-performance ceramics. Production Engineering, Vol. 11/2, Germany, 1995. 

Uematsu, T. Suzuki, K. Yanase, T. Nakagawa, T. Bekrenev, N. A new complex grinding method for ceramic materials combined with ultrasonic vibration and electrodischarge machining. The Winter Annual Meeting of the ASME, Chicago, IL, USA, 1988. 

The compression of a powder is a complex process that is usually affected by different kinds of problems. These problems have been widely investigated and mainly concern the volume reduction and the development of a strength between the particles of the powder sufficient to ensure tablet integrity [82], The application of ultrasonic energy shows a great ability to reduce and even avoid these problems [83], Ultrasound refers to mechanical waves with a frequency above 18 kHz (the approximate limit of the human ear). In an ultrasound compression machine, this vibration is obtained by means of a piezoelectric material (typically ceramics) that acts as a transducer of alternate electric energy of different frequencies in mechanical energy. An acoustic coupler, or booster, in contact with the transducer increases the amplitude of the vibration before it is transmitted (usually in combination with mechanical pressure) to the material to be compressed. 

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