中文摘要：

高温合金被广泛的应用于航空航天工业中,它是一种典型的难加工材料,切削过程刀具磨损严重。PCBN刀具作为一种超硬刀具材料在加工高温合金方面具有较大潜能,但由于PCBN刀具没有断屑槽,故断屑困难。因此研究切削参数以及刀具磨损对切屑形成的影响规律对推进PCBN刀具的应用具有重要的意义。通过试验研究切削参数和刀具磨损对切削力、切屑宏观状态和切屑微观参数（切屑剪切角、切屑厚度、齿高和齿间角）的影响规律。试验结果表明：当切削速度为97 m/min,切削深度为0.1 mm,进给量为0.14 mm/r时,切屑的宏观状态最佳。并根据试验结果,确定了绝热剪切带的位置和两个切屑锯齿形成的关系,进而建立了PCBN刀具切削高温合金GH4169的锯齿形切屑的形成机理模型：当刀具运动到某一点开始出现绝热剪切带,继续运动到下一点,形成一个锯齿,继续运动将出现下一个剪切失稳。

英文摘要：

Superalloys are applied in the aerospace industry, and it is one of classical difficult-to-cut materials, which cause the exacerbation of cutting tool wear. Polycrystalline cubic boron nitride（PCBN） is super-hard cutting tool material, which has a big potentiality in machining superalloys. However, there is no chip breaker on PCBN tool, so that it is difficult to break chip. Therefore,it is very important to research the relationship between the chip generations and both cutting parameters and tool wear for application of PCBN tools. The experiment was done to make sure the relationships cutting force, chip macro- sharp and micro-sharp with the cutting parameter and tool wear. The results demonstrate that the best chip macro sharp can be obtained when v=97 m/min,ap=0.1 mm and f=0.14 mm/r. Also the position of adiabatic shear band and the sequence between two saw teeth of chip based on the result of the test. Then the model of generation of saw-tooth chip is presented： in the process of cutting of GH4169 with PCBN tool,adiabatic shear band is generated when cutting tool is at a point, and then the saw tooth of chip is formed at a next point, after which the next adiabatic shear band can be generated.