超声振动螺线磨削表面微观形貌建模与仿真研究

Research on Modeling and Simulation of Surface Microtopography in Ultrasonic Vibration Spiral Grinding

为了实现高效率、高质量、低损伤的硬脆材料加工,对工件或砂轮同时施加砂轮轴向和径向的超声振动,该方法的显著特点是磨粒切削轨迹呈三维空间螺旋线型,将其定义为超声振动螺线磨削方法。在磨削工艺和二维超声振动的多参数共同作用下,材料去除机理产生复杂变化,表面微观形貌创出过程变得极其复杂。为此,提出一种超声振动螺线磨削加工表面数值仿真方法。基于超声振动螺线磨削几何映射关系,建立磨粒相对工件的空间螺旋线切削运动模型,进而给出超声振动螺线磨削加工表面生成模型,模拟出普通磨削和超声振动磨削的三维表面微观形貌,对比分析了超声振动对表面形成过程的影响规律。最后将仿真表面与磨削试验表面对比,发现两者微观形貌特征规律基本一致,验证了仿真方法的正确性和有效性。

In order to achieve high efficiency, high quality and low damage machining of hard brittle materials, additional ultrasonic vibrations in the axial and radial directions of workpiece/grinding wheel are applied simultaneously while grinding. The unique property of this technique is the cutting trajectory of abrasive grain is a spiral line. Accordingly, this technique is named as ultrasonic vibration spiral grinding method. Under the interactions of processing parameters and two-dimensional ultrasonic vibrations, the material removal mechanism becomes more complex, as well as the formation process of surface microtopography. Thus, a numerical simulation method of surface formation in ultrasonic vibration spiral grinding is proposed. Based on the geometric mapping relationship between grains and workpiece in ultrasonic vibration spiral grinding, the spiral cutting and motion model of grains is established. The surface formation model of ultrasonic vibration spiral grinding is provided afterward. Consequently, the three-dimensional surface microtopography of conventional grinding and ultrasonic vibration spiral grinding are simulated respectively. Then, the influence laws of ultrasonic vibrations on the surface formation process are comparatively analyzed. At last, the simulated surfaces are compared with the experimental grinding surfaces and their microstructures are found to be in the same manner, which proves the validity of this simulation method.