جستجوی مقالات مرتبط با کلیدواژه « doe » در نشریات گروه « مواد و متالورژی »

Graphite has recently received a lot of attention due to its numerous applications as well as its unique structure. Machining and machining conditions optimization are very important in reducing machining forces among other benefits. In this study, the effect of machining parameters such as spindle speed, cutting depth and feed rate on the machining forces was investigated and the optimization of these conditions was done to minimize the forces. This research uses the design of experiments to optimize the initial parameters to minimize machining forces. These experiments are based on the response surface method and analysis of variances used to identify the most effective factors in machining forces. The values of the primary parameters that provide the experiments design software are considered to be the spindle speed between 1000 and 3000 rpm, the feed rate between 1000 and 3000 mm/min, and the cutting depth between 3 and 9 mm. The results show that the machining forces increase by increasing the cutting depth and feed rate and decrease by increasing the spindle speed. The results obtained from the optimization also indicate that the machining forces reduced to their minimum value at the feed rate of 318.2072 mm/min, the cutting depth of 0.9546 mm and the spindle speed of 2356.7439 rpm.

A full factorial design of experiment was applied running 36 experiments to investigate the effects of milling parameters including cutting speed with three levels of 62.83, 94.24 and 125.66 m/min, feed rate with three levels of 0.1, 0.2 and 0.3 mm/tooth, cutting depth with two levels of 0.5 and 1 mm and machining media with two levels, on surface integration properties of magnesium AZ91C alloy such as grain size, secondary phase percent, surface microhardness and surface roughness. In all cases, a fine grained surface with higher secondary phase sediment and microhardness obtained comparing the raw material. According to analysis of variance results, the most effective parameter on grain size, secondary phase percent and microhardness was cutting depth and the most effective parameter on surface roughness was feed rate. although the grain size in all machined samples was smaller than that of the raw material but due to the dual effect of cryogenic conditions, which both cool and lubricate and reduce the temperature and strain rate at the same time, the direct effect of this parameter on grain size was not significant. Also, the all interaction effects of parameters on grain size and microhardness were significant.