...forms Hard stone is preferably used as a material for frame components for precision measuring and manufacturing machines. The principal rea- sons for this are the high attainable shape accuracy in the sub-micrometre range, low surface roughness, high resistance to mechanical wear, good long-term form stability and good damping characteristics. The high costs of such components are determined, regardless of the batch sizes, by the high amount of mechanical and manual process- ing involved in the grinding and honing. The requirements with regard to uniformity, freedom from cracks, density, size and workability are met only by hard stones from a few quarries worldwide. The locations of the deposits as well as the dependence on the weather of the quar- rying and transport lead – in addition to the high costs of machining – to delivery times of up to one year. In order to be able to counteract the unavoidable risks connected with natural materials and to improve the availability in terms of time, an expensive intermediate storage of rough-machined stone blocks is necessary. In recent years the continuous further development of hydraulically bound concrete has brought forth hardened concrete properties that are comparable with the material properties of hard stone. It can therefore be regarded as an inexpensive alternative to hard stone that enables much greater freedom in its shaping. Nonetheless, concrete is currently used only to a small degree in machines and devices and mainly in the form of base beds. The use of concrete as a material for the frames or frame components of precision devices is still in the infancy of its development, in particular with regard to the use of master functional geometries [1-4].
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