Papers by Keyword: Crystal KDP

Abstract: Fractal and wavelet methods have been used in this study to analyze the KDP surfaces machined by accurate milling and SPDT (Single Point Diamond Turning) method respectively. Through the 2D wavelet method, the 3D origin machined surfaces were separated into the 3D overlaying roughness surfaces and 3D material structure surfaces. The overlaying roughness surfaces were composed of a large number of length scales superimposed roughness surfaces that are generated from the various vibrations in the machining process. The wavelet method can analyze the information of spatial frequency (vibrations in the machining process) and fractal method can reveal the intrinsic properties of roughness topography. Compared with the conventional methods, the integration of wavelet and fractal is more suitable to characterize the machined crystal KDP surface.

Abstract: Influence of the cutter rake angle to the surface quality of crystal KDP is analyzed theoretically in this paper. Analysis result shows that the tension stress reaches minimum in the crystal KDP cutting region and optimal value of the surface quality is obtained as cutter rake angle is about -45°. Cutting experimental of different cutter rake angle is realized on the machine tool. Experimental results show that the surface roughness of the crystal KDP reach minimum (rms is 6.521nm, Ra is 5.151nm) as the cutter rake angle is about -45°, this experiment certifies the correctness of this theory analysis. Theory analysis and experimental results show that influence of the cutter rake angle to surface quality of the crystal KDP is very large, for ultra-precision machining of the crystal KDP, when large negative rake diamond cutter (-45°) is adopted, the super-smooth surface can be obtained.

Abstract: A theoretical analysis on the variation regularity of cutting force caused by the material anisotropy with different orientation of KDP is analyzed firstly; influence and regularity of the variation are obtained. Analysis result shows that the crystal anisotropy of KDP is an important factor in obtaining the super-smooth surface. Then experiments are realized on the machine tool, results afford the variation regularity of cutting force caused by the anisotropy with different orientation of KDP, which certifies the correctness of this theoretical analysis. For ultra-precision machining of the KDP at large negative rake diamond cutter (-45°) and the optimal parameters, the super-smooth surface (rms is 8.702 nm, Ra is 6.895 nm) can be obtained on the plane (001).