瞬时有效磨粒数影响因素仿真研究

The simulation study to the influential factors of the instantaneous effective abasive number

在磁感应游离磨粒线锯切割过程中,吸附到锯丝上的瞬时有效磨粒数对切割性能有很大的影响.基于锯丝周围形成的高梯度磁场中磁性磨粒的受力分析,从研究磨粒运动着手,将切削液视为连续介质,磁性磨粒为离散体系,综合考虑磨粒所受的磁力、磨浆流体曳力,应用有限元软件COMSOL进行了磨浆的供浆方向、供浆速度和切削液动力黏度对瞬时有效磨粒数影响的仿真研究.结果表明:磨浆的供浆与磁场方向平行时,更多瞬时有效磨粒集中吸附在锯丝的一侧参与切割;随着供浆速度的增大,瞬时有效磨粒数较少,1s内锯丝吸附的有效磨粒总数先增加后减少,当供浆速度为12mm/s时,有效磨粒总数最多;选取切削液动力黏度为0.004 7Pa·s,瞬时有效磨粒数较多且磨粒在切削液中分散性较好.

In the process of magnetic induction-free abrasive wire sawing,the number of instantaneous effective abrasives adsorbed on the saw wire has a great influence on cutting performance.Based on the force analysis of magnetic abrasive in a high gradient magnetic field produced around the saw wire,the movement of magnetic abrasive is studied.The cutting fluid is regarded as a continuous medium and magnetic abrasive as the discrete system.Besides,magnetic force and fluid drag force of magnetic abrasive are comprehensively considered.The effects of slurry feed direction,slurry velocity and fluid dynamic viscosity are simulated by finite element software COMSOL.The results show that more abrasives are adsorbed at the side of the saw wire when the slurry feed direction is parallel to the magnetic field direction;With the increase of the speed of supply,the instantaneous effective abrasive grain number is less,the total number of effective grinding grains is increased firstly and then decreased within 1 s,when the supply speed is 12 mm/s,the total number of effective abrasive is the most.Furthermore,there are more instantaneous effective magnetic abrasives when the cutting fluid dynamic viscosity is 0.004 7 Pa·s,in this case the abrasives have well dispersibility in the cutting fluid.