The research object is 40Cr shaft parts after quenched and tempered. Optimize the main process parameters working pressure, frequency and amplitude of ultrasonic finishing. It is obtained that the various parameters influence the surface roughness of the machining samples and the optimum technological parameters combination which is consistent with experimental results. Using the SPSS software to analyze the results, obtained the process parameters impact trend of the postprocessing roughness. Contrast groups of test data, the best result was reduced by 98.4% compared with the initial roughness , reached the Ra0.04μm.
Based on the characteristics of the machine, wire walking agencies, table feed system and the circuit control section has been studied in combination with all kinds of WEDM. The machine use PLC to control the campaign of wire walking agencies, using the trip switch to control motor reversing, controlling the movement of the machine table through MCS-51 series single-chip and using high-frequency pulse-way power offers a range of different pulse width of the rectangle for WEDM .In this way ,it simplifies the overall structure of the machine and improves efficiency of the feed system and cutting performances.
Magnesium-based hydrogen storage powders were prepared by reactive milling under hydrogen atmosphere. The crystallitic carbon, prepared from anthracite coal by demineralization and carbonization, was used as milling aid and synergic hydrogen storage additive of magnesium. Dispersive powders of particle size about 20 to 60 nm and hydrogen capacity of 4.78 wt.% were prepared from magnesium with 40 wt.% of crystallitic carbon by 3 h of milling under 1 MPa of hydrogen atmosphere. The hydrogen stored in carbon increased with the addition of Al, Mo, Co and Fe. FT-IR showed that the carbon atoms at the edges of crystallitic carbon particles were hydrogenated into C-H during reactive milling with hydrogen. The initial dehydrogenation temperature of hydrogen-storage material 60Mg40C is 275.8 °C, and its dehydrogenation plateau pressure at 300 °C is 0.2 MPa and the length of the plateau is 5.0 wt.% of hydrogen capacity.
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