Dynamic machine coefficient

Last but not least, one should not forget that for practical applications the hardness at room and at a high temperature is only one of many properties which determine the applicability of a material. Further mechanical properties, such as fracture toughness under static and dynamic load, coefficient of friction, corrosion resistance, and reactivity with the material to be machined at room as well as at elevated temperature are decisive for most applications. 

It is important to notice that gt and 1 lgt may have a large dynamic range in practice. For example, if fee [- 1 + e., 1 - e ], the transformer coefficients may become as large as j2jt — 1. If eis the machine epsilon, i.e.,e = 2 ( )for typical n-bit two s complement arithmetic normalized to lie in [-1, 1), then the dynamic range of the transformer coefficients is bounded by s/2n - 1 2n. Thus, while transformer-normalized junctions trade a multiply for an add, they require up to 50% more bits of dynamic range within the junction adders. 

To assure full film lubrication, a copious supply of oil is necessary. Former experiences with a pin and disc machine learn that jet lubrication will be convenient. An extreme pressure gear oil was chosen because of its high dynamic viscosity and high pressure-viscosity coefficient. 

Figure 6b and c shows the dynamic compliance and corresponding phase shift of the indenter (uncorrected for electronics). The response was fit to the model in Fig. 6a for this indenter the damping coefficient, Q is 0.008 Ns/m, resonance frequency, Q)o is 110 Hz, indenter mass, m is 236 mg, and spring constant, Ki is 116 N/m. A Berkovich diamond indenter with a tip radius of -200 nm was used for all experiments. Tip shape calibration and machine compliance were determined by standard techniques (14) using electropolished indium and quartz. 

The method for the dynamic evaluation of machine tools under test conditions has been described. The procedure evolved, covering the determination of the response data (and from this that of the operative receptance locus ), the prediction of the stability chart, the concept of the coefficient of merit describing machine quality, will be summarised in relation to the particular case of the bonded machine. 

The relative dynamic performance of the two machines is measured by the relative improvement coefficient (RIC), being defined as ... 

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