Experimental Study of Machinability in Millgrinding of SiCp/Al Composites

An attempt was made to investigate the machinability of Si Cp/Al composites based on the experimental study using mill-grinding processing method. The experiments were carried out on a high-speed CNC machining center using integrated abrasive cutting tool. The effects of combined machining parameters, e g, cutting speed(vs), feed rate(vf), and depth of cut(ap), with the same change of material removal rate(MRR) on the mill-grinding force and surface roughness(Ra) were investigated. The formation mechanism of typical machined surface defects was analyzed by SEM. The experimental results reveal that with the same change of material removal rate, lower mill-grinding force values can be gained by increasing depth of cut and feed rate simultaneously at higher cutting speed. With the same change of MRR value, lower surface roughness values can be gained by increasing the feed rate at higher cutting speed, rather than just increasing the depth of cut, or increasing the feed rate and depth of cut simultaneously. The machined surface of Si Cp/Al composites reveals typical defects which can influence surface integrity.     

SiCp／Al窄槽的铣磨实验研究——磨削力

针对SiCp／Al复杂曲面加工中大去除量、高精度的需求,以窄槽的铣磨加工工艺为例,实验研究SiCp／Al窄槽铣磨加工中加工参数、铣磨工具对铣磨力的影响规律．实验结果表明:加工参数和铣磨工具均对铣磨力有影响．在实验参数取值范围内,铣磨力随砂轮线速度、进给速度的增大而增大,进给速度对铣磨力的影响最大;采用螺旋槽铣磨工具可显著降低铣磨力,但铣磨力波动较大,并随螺旋角的增大而减弱．在实验条件下,可优选铣磨力波动相对较小的50°螺旋角的开槽砂轮进行窄槽的粗加工．     

Combined rough and finish machining of Ti–6Al–4V alloy by electrochemical mill-grinding

Abstract

This study proposes a combined method for the electrochemical mill-grinding of Ti–6Al–4V alloy to achieve a high material removal rate, high machining accuracy and good surface quality based on rough and finish machining. In the rough machining stage, a maximum feed rate of 2.7?mm min^?1 and a material removal rate of 248.3?mm³ min^?1 were achieved experimentally at a 10?mm cut depth using an abrasive tool with five rows of tool-sidewall outlet holes. In the finish machining stage, there were almost no overcuts or stray corrosions produced. The sidewall surface roughness and sidewall flatness were Ra = 1.06 and 76.8?μm after the finishing stage, which represent a 68% and 79.2% improvement compared with the rough machining stage, respectively. Finally, we fabricated a 1-mm-thick thin-walled structure using the combined machining operations, in which approximately 96% of the total material removal volume was performed at the rough machining stage.     

先进陶瓷材料超声振动铣磨加工表面粗糙度仿真及实验(英文)

为了对超声振动铣磨加工先进陶瓷的表面粗糙度进行预测,建立了加工表面形貌的仿真模型.通过实验测得砂轮表面形貌和磨粒突出高度信息,并对这些信息进行Kolmogorov-Smirnov正态验证,发现砂轮表面形貌不服从高斯分布.对非高斯分布的数据进行Johnson变换,建立砂轮形貌的数值模型.结合砂轮表面形貌和磨粒与工件的相对运动分析,提出了一种表面轮廓搜索方法,进而生成了加工表面的三维形貌.最后,在DMG ULTRASONIC 70-5 linear机床上进行切削实验,对仿真结果进行了验证,结果表明仿真与实验结果具有较好的一致性,并对仿真误差产生的原因进行了分析.     

球头阴极电解铣磨加工TC4钛合金试验研究

采用直径6 mm的球头阴极,通过内喷液式的供液方式,对TC4钛合金进行电解铣磨加工粗精加工试验研究.结果表明:采用球头阴极可以实现底面为曲面的沟槽加工,电解铣磨加工方法可以对沟槽进行连续的粗精加工,实现TC4钛合金曲面沟槽的高效精密加工.