tailieunhanh - Handbook of Advanced Ceramics Machining Episode 3

Tham khảo tài liệu 'handbook of advanced ceramics machining episode 3', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 46 Handbook of Advanced Ceramics Machining uw mm sec a SD140Q50M b SD800Q50M FIGURE Influence of the table speed and wheel grain size on the ground HIPSN surface Vg 20 m sec tt 5 mm Soluble 1 50 . microholes which are considered to be pores in HIPSN itself or fracture traces of fragile portions inside HIPSN becomes very smooth. Thus a smooth ductile-mode ground surface can also be obtained with plunge grinding of HIPSN ceramic with the coarse 140-mesh wheel. Ultra-smoothness Grinding Ultra-smoothness Grinding Method As stated above ductile-mode grinding of fine ceramics is possible with plunge grinding with the coarse 140-mesh grain-size diamond wheel. The 3D surface roughness in ductile-mode plunge grinding however is limited Ductile-Mode Ultra-Smoothness Grinding of Fine Ceramics 47 RMS nm Surface WVLEN nm RA nm Masks None R Crv mm P V 238 nm R Cyl mm Orientation 0 Front 98 51 -3 -44 -91 U 98 nm L -91 nm RMS RA P V WYKO nm nm nm Profile WVLEN nm R Crv m 50 97 145 192 . 3 Distance on surface microns WYKO 239 FIGURE A WYKO 3D image and 2D profile of the HIPSN surface ground at nw mm sec with the 140-mesh wheel SD140Q50M Vg 20 m sec tt 5 mm Soluble 1 50 . to about 200 nm Rmax in the above-mentioned experiments because of the formation of grinding grooves. The 3D surface roughness of 200 nm Rmax is much better than the well-known data obtained in the usual grinding operation. However the ultrasmooth roughness below 10 nm Rmax which is almost the same as that after lapping could not be obtained in plunge grinding. To obtain ultra-smoothness roughness with the coarse-grain-size wheel it is necessary to diminish and remove the grinding grooves. Now the ultra-smoothness grinding method has been newly devised 5 6 . The schematic of the new method is shown in Figure . In the method the workpiece is fed simultaneously toward the directions normal and