| Research Abstract |
This research aims to investigate experimentally the attainable limiting surface smoothness in the ultra precision cutting of various kinds of materials. The relationship between the cutting condition and the surface roughness for face-turning of various kinds of materials is investigated experimentally. The turned surface is observed with micrograph and SEM.The surface roughness is measured with WYKO and AFM.The main results obtained are as follows :
1) The ultra precision face-turned workpiece surface consists of the micro-defect such as micro-hole and scratch, the grain boundary of material, the feed transcription groove of bite edge radius and the micro-waviness due to the machine characteristics and circumstance conditions such as the room temperature, floor vibration and so on.
2) Within the range of a critical feed rate, the surface roughness becomes small as the feed rate is small. Over the critical feed, on the other hand, the surface roughness converges into a terminal constant
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value.
3) The cutting speed and depth of cut have little influence on the attainable limiting surface smoothness.
4) The attainable limiting surface smoothness is dependent on the workpiece material and range from 9nm (Rmax) to 5nm (Rmax), excluding the micro-defect formed in Al-Mg alloy.
5) The grain boundary step and micro-turbulence of bite edge shape is below 5nm and 2nm, respectively.
6) In the limiting ultra-precision cutting of Ni-P amorphous material and gold, no and little formation of the grain boundary step is observed. As the result, the surface roughness of those materials becomes smaller than other materials such as Al alloy and OFHC copper.
7) According to the observation for the extremely micro-area of 500nm square, the ultra-precision face-turned surface of various kinds of work pieces excluding the gold consists of a plenty of particles. In the gold, on the other hand, the cutting grooves are observed.
8) In the ultra precision cutting of the stainless steel, the bite edge wear is confirmed to be aggressively even in the good cutting condition for it. Less
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