Zero Width Glass Cutting with CO 2 Laser
Laser cutting of glass in not a novel technique, excellent results have already been achieved by various research institutes. There are several patents concerned with controlled cutting of glass with zero width and other brittle materials in a straight line using CO2 laser beam. Laser beam glass cutting produces a high quality cut edge with minimal microcracking. This is achieved using a controlled cleaving of glass through a combination of heating and cooling. Laser separation of glass with zero width can be summarised by the following steps:
Laser separation of flat glass in electronic-, optic-, display-, and bio-industry (Invited Paper)
Up until now, conventional cutting methods by using metal or diamond wheels have been widely in use in numerous glass industries. Along with the market trend towards clean and more sophisticated process, constraints by the traditional methods have been unavoidable. Hence, laser separation is seen as an alternative and breakthrough solution to many and in this paper, an overview on laser separation as a whole is provided in terms of its process theories and its system as process equipment. Also glass application varieties as well as market requirements are discussed.
Microstructure of the solder-casting zone in bridges of dental gold alloys.
The composition and structure were studied in the cast and in the solder of bridges which had failed clinically. Both materials were gold alloys but with different contents of Pt, Ag and Zn. The metallographic investigation revealed defects mostly in the solder, situated in the subsurface layer. SEM studied of the fracture surface revealed large porosites and a structure of dense parallel lines--striations--, indicating that the material had failed from fatigue. The materials in the fractured bridges were identified by micro-probe measurements. It was stated that cast material and solder material used together, were of different composition.