Concrete and ceramic machines: varieties, pluses

At the International Twelven Exhibition of machine tools, held in Japan, machines from non -traditional materials were shown. The processing center (multioperative machine), developed by Fujita and Hamai, has a bed and a column made of reinforced concrete. As far as is known, this is the first such case in world practice.

What does the concrete bed give, reinforced with segments of steel wire? The vibration is approximately twice (concrete has shock -absorbing properties), and this reduces the wear of the tool as many times. The noise is reduced by 10 decibels, a machine with concrete parts by 20 percent cheaper than “all -metal”. True, it is about a third heavier than usual, but this drawback can rarely be crucial.

The attention of experts was attracted by Eguro and Kiocera, a small -sized super -presidential current machine with the widespread use of ceramic materials. It is intended for processing with high accuracy of heads for video recorders and mechanical parts of memory devices for personal computers. Spindle, stubborn bearings, sliding bearings are made of silicon nitride and installed in a spindle sleeve made of aluminum oxide. A bed, front grandmother, transverse sledges and some other details are made from it. Ceramics are easier than metal, almost does not expand when heated, is very resistant to wear. The last two qualities have made it possible to achieve a special accuracy of processing: the machine provides the accuracy of a given diameter of the part of 0.2 micrometer, and the height of the remaining micronerings of the treated surface is 0.02 micrometer.