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Electrochemical discharge machining (ECDM) is the preferred non-traditional process technology in recent years, The main processing is applied to machining non-conductive hard brittle materials. This study investigated the precision and stability of quartz fabricated by ECDM and explored the optimal processing parameters including size of electrode, machining speed as well as pulse-on and pulse-off duration. Microgrooves machined under the optimal processing parameters with adjusted rotational speed and feed rate were examined to understand the effect of different ECDM parameters on machining performance. The results indicate that micro-holes of better morphology could be obtained under pulse voltage of 40 V, electrolyte concentration of 5 M, electrode size of 125 μm. Moreover, rotational speed of 1500 rpm and pulse-on/pulse-off (ms) ratio of 1:0.6 gave higher machining accuracy with smaller hole diameter and shorter machining time. Finally, microgrooves machined under the optimal processing parameters showed the best accuracy in dimension and cross-sectional morphology at rotational speed of 2500 rpm, pulse-on /pulse-off (ms) ratio of 1:1.6, and feed rate of 3000 μm/min.

This study examined the surface defects and surface roughness of optical glass polished by mechanochemical machining. BK7 optical glass material was polished using cerium oxide (CeO2) solutions of different concentrations and temperatures. During machining, the optical glass specimen was placed between the ceramic working ring and the polishing pad. The effects of slurry concentration and temperature, polishing time, rotational speed and axial load on the surface roughness were examined. Significant improvement in surface roughness could be attained by polishing with CeO2 slurry of 95。C. Both SEM and AFM images of BK7 polished under conditions: slurry concentration, 15%; slurry temperature, 95。C; rotational speed, 40 rpm; axial loading, 6 kg; and polishing time, 8 min show that the optical glass specimen surface had high transmittancy and became smooth with all scratches removed. The best mechanical properties in terms of Young’s modulus of elasticity and hardness were obtained by polishing with CeO2 slurry of 60。C. Although better surface roughness can be attained with further increase in slurry temperature, the enhanced reaction under high slurry temperature undermined the mechanical properties of the glass specimen.

Wire electrical discharge machining (WEDM) of polycrystalline silicon (polysilicon) involves high-temperature melting that easily produces cracks on the silicon surface. This paper studies improvements of cracks and craters on surface of polysilicon after wire electrical discharge machining (WEDM) by magnetic force-assisted electrolytic machining (MFA-EM). The effects of different MFA-EM parameters on material removal and surface roughness are explored to understand the machining characteristics of MFA-EM and how magnetic field assistance contributes to high-efficiency and high-quality machining. Experimental results show that compared with standard EM, MFA-EM can achieve better machining efficiency and surface quality because MFA-EM can effectively enhance electrolyte circulation and replenishment, which contributes to better machining stability.

This study investigates a spiral polishing mechanism in polishing the inner wall of stainless bore with the mixture grinding material of silicon carbide and polystyrene. The delicate polishing process is verified to be more efficient, cost-saving, and environment friendly than traditional processes. Varied sets of polishing parameters, including SiC grain size, SiC weight, polystyrene(PS) weight, viscosity of silicon oil, revolution speed of the driving screw, and machining time, are examined through the Taguchi Methods for optimum polishing effects. Impacts of different combinations of the six polishing parameters on surface roughness and texture are probed into and analyzed in the process of the experiment. The findings suggest that with the increase of time, the fluidity and stickiness of the abrasive medium improve, resulting in a finer polished surface within delicate spiral polishing process. It appears that significant differences are observed through the use of a mixture of 60 grams of SiC (with size of 7 μm) and 70 grams of polystyrene, silicon oil of 1000 mm2/s viscosity under the speed of 3500 rpm screw revolution speed for 30-minute machining time, improving the surface roughness from 0.90 μm to 0.158 μm Ra. The finding thus lends support to the effect of spiral polishing mechanism, which can be further developed.