单晶硅料摆辅助多金刚线切片的锯切力模型研究

Research on Cutting Force Model of Diamond Wire Saw with Single Crystal Silicon Swing

料摆辅助多金刚线切片技术是实现硬脆材料高精高效加工行之有效的工艺技术,探明其工艺参数、锯切力和切片质量的定量关系,具有重要的现实意义。在研究金刚线运动轨迹的基础上,推导了考虑线弓影响的切割长度变化公式;结合压痕断裂力学和试验研究,建立并验证了料摆辅助切片的锯切力模型。开展了不同工艺参数对锯切力的影响分析,结果表明,料摆辅助加工可以降低锯切力近50%;摆动角度对最大切割力的影响较小,但摆角增大会加剧"锯齿形波动"周期内的锯切力极值幅度,摆动角速度对"锯齿形波动"的周期影响较大;在恒定进给速度条件下,进给速度越高,锯切力越大;在变速进给条件下,最大锯切力可降低12%左右。进一步进行了摆角分别为0°、3°、5°和7°的多金刚线切割单晶硅实验,试验表明,料摆辅助切片加工有助于减少硅片表面因脆性崩裂产生的表面材料破损、深凹坑等缺陷;相较于普通切片加工,在摆角5°工况时,工件的表面粗糙度和硬化层厚度最大分别降低30.1%和20.1%。

Material pendulum assisted multi diamond wire sawing technology is an effective technology to realize cutting hard and brittle materials with high precision and high efficiency. It is of great practical significance to explore the quantitative relationship among the parameters, cutting force and chip quality. The length variation formula of cutting line with the influence of wire bow has been deduced on the basis of researching diamond wire trajectory, and the theoretical model of diamond wire sawing with single crystal silicon swing has been established and verified combined with indentation fracture mechanics and experiments. The analysis of the influence of cutting force under different parameters has conducted, and the results show that the cutting length can be reduced by nearly 50% with the aid of pendulum. The swing angle has little effect on the maximum cutting force, but it can affect the extreme range of cutting force in the "sawtooth wave" period, and the swing angle velocity has a greater impact on the "sawtooth wave" period.The cutting force increases with the increase of feed rate under the condition of constant feed rate, and the maximum cutting force can be reduced by about 12% under the condition of variable feed rate. After further experiments of multi diamond wire slicing with swing angles of 0°, 3°, 5° and 7°, the results show that diamond wire sawing with single crystal silicon swing can reduce the defects of material surface damage and deep pits. Compared with the 0°experiment, the silicon wafer with a swing angle of 5°reduces the roughness by 30.1% and the thickness of the hardened layer by 20.1%.