Microdrilling machines operate drills having very small diameters or oscillating styli with exceedingly fine points. They are used when the size of the hole or the depression to be made decreases to such an extent that observation with optical aids during drilling becomes desirable or necessary. Several microdrilling machines have been developed for work under the microscope (41, 132, 138, 197). One of these machines (132) is capable of making depressions as small as 10 μm in diameter. Another machine (41, 197) is capable of drilling holes of even smaller size. Such tiny holes or depressions may be made in hard material requiring considerable force to penetrate, such as metals, alloys, minerals, and refractory materials. The depth of penetration and the size of the resulting cavities can be controlled. In metallurgical investigations, i. e., for taking samples from localized spots and for removal of inclusions of the order of one to a few cubic millimeters, Koch et al. (138) use microdrills of comparatively large size. These microdrills may be made of hard steel or a hard metal fitted with diamond splinters. Such splinters are available in sizes of about 1 to 1.5 mm, while the steel tools are of about 0.5 mm in diameter. The microdrilJs are mounted on a micromanipulator, and are of various shapes to suit different operations such as boring, widening the drill hole, and grinding the separated sample.
KeywordsRemote Control Base Plate Hard Material Barium Titanate Twist Drill
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