FAW加工过程线锯振动建模与实验验证

Modeling and experimental verification of wire vibration for FAW cutting process

在分析Si C单晶切割过程的基础上,建立了固结磨粒线锯(FAW)加工过程中的横向振动模型,该模型为有阻尼的轴向运动弦线的受迫振动模型。采用激光测振仪测量线锯的振动,运用非切削与切削实验验证了振动模型的准确性和线锯振动测量方法的有效性;对线锯横向振动最重要的影响因素——线锯张力进行了分析和标定。张力从17N增加到23N以及从17N增加到24N的实验结果表明:张力改变对振动幅值影响较小,但使振动第一阶频率变化明显,前者变化导致频率增加9%,后者变化导致频率增加18%,而且频率不随张力线性变化;其他切削参数不变,进给速度在0.25mm/min^0.75mm/min内变化,振动频率变化小于3%;假定张力在测量中无变化,则轴向速度在1.3m/s^1.9m/s内变化时对线锯振动并无影响。研究结论为线锯加工的张力控制提供了分析基础。

Based on the analysis of the cutting process of the Si C ingot, the transverse vibration modeling of Fixed Abrasive Wire saw(FAW) is proposed. It is stated that the vibration modeling of wire saw processing can be described as an axially moving string with damping. To verify the accuracy of the vibration modeling and the effectiveness of wire vibration measurement, cutting and non-cutting experiments are carried out and the laser vibrometer is used for vibration measurement of the wire saw. Furthermore, the wire tension, which is the most important factor affecting the wire saw vibration, is analyzed and calibrated. Results obtained show that the change of tension has little effect on the vibration amplitude, but the first order frequency change is obvious. When the tension varies from 17 N to 23 N or from 17 N to 24 N, the frequency varies by 9% or 18%, and the frequency does not change linearly with the tension. When the feed rate changes within 0.25 mm/min ~0.75 mm/min with other cutting parameters unchanged, the vibration frequency variation is less than 3%. If it is assumed that no change in tension in the measurement, the axial velocity within 1.3 m/s ~1.9 m/s has no effect on wire saw vibration. These conclusions may lay theoretical foundations for the control of wire saw tension in the cutting process.