The purpose of this experimental research are investigation the growth behaviors of the
oxide layer at different pre-dressing conditions in ELID pre-dressing, effects of voltage and duty
ratio of the power supply, wheel speed on the oxide layer formation characteristics on the metal
bond diamond wheel surface. The results indicated that the oxide layer thickness on the wheel
surface increase with pre-dressing time. The oxide layer growth rate is faster in beginning period
time of pre-dressing process then slow down. Both the thickness and growth rate of oxide layer
increase with the increase of duty ratio and applied voltage. It takes longer time for oxide layer
growth rate to reach to stable state in lower duty ratio condition than in higher duty ratio condition.
There are no effects of wheel speed on oxide layer growth behaviors in the wheel speed range of
1000rpm to 4000 rpm.
The machining characteristics of SiC/Al composite using wire electro discharge machining (WEDM) were investigated in this study. Material cutting speed and surface roughness value were adopted to evaluate the machinability. Peak current, pulse on time, pulse duration and working voltage were selected as the input variables to investigate the machining performance. Effects of input variables on the cutting speed and surface roughness were experimentally tested. Peak current, pulse on time and working voltage were confirmed to have positive effects on cutting speed and surface roughness value. Whereas the cutting speed and surface roughness value decrease with the increase of pulse duration.
This paper mainly studies the change rules of interior ballistic performance under different loaded conditions, especially the maximum pressure and the muzzle velocity. There are six parameters affect the performance. The results show that, changing one of the all parameters, the maximum pressure and velocity will be increased with the increase of propellant shape coefficient χ; increased with the charge increases; increased as the propellant force increases; decreased with the chamber volume becoming bigger; increased with the engraving pressure increases; the maximum pressure increases while the velocity decreases with the mass of the projectile increases. In order to improve the interior ballistic performance, these loaded conditions must be paid attention.
An open motion control system of the engraving machine is developed. IPC and GE-300 motion control card constitute the main part of the hardware platform and windows system is used as the software development platform. Modularization programming technology is applied to design the software system of the machine to make programming easy. Based on the function and performance requirements of the engraving machine, the whole control system consists of initialization module, parameter setting module, coding module, manual processing module and inverter-motorized spindle module. The design philosophy and method of these modules are presented in this paper.
Water hydraulic components have been developed rapidly in recent years. However many problems such as low lubricity and leakage limited the performance of them, especially water proportional valves. A proportional valve- hydraulic cylinder system with tap water as working medium is chosen as object to investigate the performance of water hydraulic system. With regarding to the weaknesses of the selected 4/3 proportional valve including lag, dead zone and nonlinearity, an integral separation PI arithmetic based close-loop controller is developed. Experiments results verified the electro-hydraulic proportional system of fast response speed and high accuracy.
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