Machinable glass

Cere Vita Mark It Machinable glass ceramic Vita Zahnfabrik, Bad Sackingen, Germany... 

A practical unit of detector is composed of a silicon wafer, an indium foil of 0.5 mm thick and a substrate of machinable glass. The indium foil makes electric contact with the aluminum layer on the wafer. The dimensions of the wafers and the substrates are as follows ... 

Kicka, L.J., Faro, I., Heyner, S., Garside, W.T., Fitzpatrick, G., Wilding, P., Micro-machined glass-glass microchips for in vitro fertilization. Clin. Chem. 1995, 41, 1358-1359. 

The high-speed magic-angle spinner used has been described in detail elsewhere (5). The particular one we used is constructed of Macor, a machineable glass that gives no background in the 13C CP/MAS spectra. Additional experimental details and a discussion relating this procedure to solid coals and coal derived liquids have been previously published (8). 

SACE makes use of electrochemical and physical phenomena to machine glass. The principle is explained in Fig. 1.1 [128]. The workpiece is dipped in an appropriate electrolytic solution (typically sodium hydroxide or potassium hydroxide). A constant DC voltage is applied between the machining tool or tool-electrode and the counter-electrode. The tool-electrode is dipped a few millimetres in the electrolytic solution and the counter-electrode is, in general, a large flat plate. The tool-electrode surface is always significantly smaller than the counter-electrode surface (by about a factor of 100). The tool-electrode is generally polarised as a cathode, but the opposite polarisation is also possible. 

Another very interesting commercial process is machine glass-blowing, by which bottles and other laboratory articles are made nowadays in very large quantities. The bulbs for incandescent electric lights are also made by this process, and a single machine is capable of producing as many as 20,000 bulbs per day without human... 

Glass-ceramics are also used for dental prosthetics. These materials are primarily based on either lithium disilicate or calcium phosphate glasses. Machinable glass-ceramics based on fluoromica phases have also been developed for machined inlays. All of these materials must be stained to match the surrounding teeth to be acceptable to the patient. 

Brittle fracture is used for shaping and machining ceramics after they have been fired. Ceramics can be modified to make them machinable this is controlled fracture and is the approach we adopt with machinable glass-ceramics such as Macor (Chapter 26). Of course, many ceramics already are machinable and can be shaped into intricate and beautiful forms as illustrated in the carved marble sculpture shown in Figure 18.1. 

Borosilicate glass matrix composites with chopped graphite fibres are highly machine-able materials [29]. Machinable glass-ceramics containing interlocking platelet-like and... 

The material chosen as a test material is MACOR. MACOR is a machinable glass ceramic and is a fluorine rich glass with a composition approaching trisilicic fluorphlogopite mica (KMg3AlSi30ioF2) (6). The material was acquired in a rod form. 

Dicor. Tradename. A castable, machineable glass-ceramic based on mica (tetra-silicic fluormica) with up to 7% added Zr02 to improve chemical durability and translucency for dental applications. (P.J. Adair, Dentsply International and Corning Glass. U.S. Pat, 4431420 1984)... 

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