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Herein, coating diamonds on WC–Co by using the hot filament chemical vapor deposition (HFCVD) method are discussed. CVD was performed for 8 h under a deposition pressure of 40 torr using various doping gases such as boron, nitrogen, and argon to control the particle size of the diamond thin films, the surface was then analyzed through scanning electron microscopy (SEM) and Raman spectroscopy. The SEM images confirmed that the diamond crystal size was reduced upon boron and argon doping. In contrast, nitrogen doping promoted the growth of diamond crystals. In the Raman spectra, the D and G bands were observed at 1332 and 1580 cm${}^{-1}$, respectively. Thus, the surface roughness can be controlled using a variety of doping gases, which may be used in tools.

This paper investigates the conditions for ductile-regime machining of (100) silicon wafers. Single crystalline diamond tools with 10-40 nm edge sharpness were used to machine the wafer at either a constant depth of cut, or in a taper mode to vary the depth of cut up to 1 µm. Feedrate was varied as a percentage of tool nose radius and the machining process was performed on an ultraprecision machining system. The surface and subsurface integrity were then characterized by atomic force microscopy, phase shift interferometry, and ion beam micromilling.

Ductile regime was achieved when machining along the <110> directions and the maximum chip thickness of less than 0.5 µm. Machining conditions that formed thicker chips lead to pitting, microcracks and slip lines. Such defects, could be more than 1 µm deep, were found along the <110> directions and occasionally along the <100> directions. Surface roughness below 10 nm was measured in a ductile regime area, but was as high as 170 nm in a fractured area. When cutting at a depth of cut in the magnitude of the tool edge sharpness, the surface finish was degraded due to radial cracks in the lateral plane due to rubbing between the tool and the workpiece.

This paper reports research results on ductile-mode machining of an aluminum-based MMC reinforced with Al₂O₃ particles. Both polycrystalline diamond and single crystalline diamond cutting tools were used to ultra-precision machine the MMC at the depths of cut ranging from 0.4 µm to 1.6 µm. The critical depth of cut for performing ductile-mode turning of the MMC reinforced with Al₂O₃ particles was found to be 1 µm. At such depth of cut, there was almost no sub-surface damage except rare cracked particles. Besides the depth of cut, ductile-mode machining of the reinforcing particles was also affected by the orientation of the particles.