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。
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.
[1] EZUGWU E O，BONNEY J，YAMANE Y. An overview of the machinability of aeroengine alloys [J]. Journal of Materials Processing Technology，2003，134(2)：233-253.
[2] EZUGWU E O，BONNEY J. Effect of high-pressure coolant supply when machining nickel-base，Inconel 718，alloy with coated carbide tools [J]. Journal of Materials Processing Technology，2004，153-154：1045-1050.
[3] 王殿龙，荀志峰. K24镍基高温合金切削性能试验研究 [J]. 机械工程学报，2002，38(增)：190-193. WANG Dianlong，XUN Zhifeng. An Investigation of the machinability of K24 Nickel-based super alloy [J]. Chinese Journal of Mechanical Engineering，2002，38(Suppl.)：190-193.
[4] THAKUR D G，RAMAMOORTHY B，VIJAYARAGHAVAN L. Machinability investigation of Inconel 718 in high-speed turning [J]. The International Journal of Advanced Manufacturing Technology，2009，45(5-6)：421-429.
[5] RAZAK N H，CHEN Z W，PASANG T. Modes of tool deterioration during milling of 718Plus superalloy using cemented tungsten carbide tools [J]. Wear，2014，316(1–2)：92-100.
[6] 肖茂华，何宁，李亮，等. 陶瓷刀具高速切削镍基高温合金沟槽磨损试验研究 [J]. 中国机械工程，2008，19(10)：1188-1193. XIAO Maohua，HE Ning，LI Liang，et al. Experimental studies on notchwear for high speedmachining of nickel- based superalloy with ceramic tools [J]. China Mechanical Engineering，2008，19(10)：1188-1193.
[7] JI W，LIU X L，LI Y F，et al. The mechanisms of PCBN tools in turning GH4169 [J]. Advanced Materials Research，2012，500：73-81.
[8] JI W，LIU X L，YAN F G，et al. Investigations of surface roughness with cutting speed and cooling in the wear process during turing GH4133 with PCBN tool [J]. Key Engineering Materials，2013，589-590：258-263.
[9] JI W，LIU X L，LI H Y，et al. Research of PCBN tool wear mechanism in turning Ni-based superalloy [J]. Advanced Materials Research，2013，820：185-189.
[10] JAWAHIR I S，VAN LUTTERVELT C A. Recent developments in chip control research and applications [J]. CIRP Annals - Manufacturing Technology，1993，42(2)：659-693.
[11] JAWAHIR I S，FANG X D. A knowledge-based approach for designing effective grooved chip breakers — 2D and 3D chip flow，chip curl and chip breaking [J]. The International Journal of Advanced Manufacturing Technology，1995，10(4)：225-239.
[12] SU G，LIU Z. Analytical and experimental study on formation of concentrated shear band of saw tooth chip in high-speed machining [J]. Int. J. Adv. Manuf. Technol.，2013，65(9-12)：1735-1740.
[13] THAKUR D G，RAMAMOORTHY B，VIJAY ARAGHAVAN L. A study on the parameters in high-speed turning of superalloy Inconel 718 [J]. Materials and Manufacturing Processes，2009，24(4)：497-503.
[14] KONG X，LI B，JIN Z，et al. Broaching performance of superalloy GH4169 based on FEM [J]. Journal of Materials Science & Technology，2011，27(12)：1178-1184.
[15] SIEMERS C，ZAHRA B，KSIEZYK D，et al. Chip formation and machinability of nickel-base superalloys [J]. Advanced Materials Research，2011，278：460-465.
[16] Z?BALA W，S?ODKI B. Cutting data correction in Inconel 718 turning [J]. Int. J. Adv. Manuf . Technol.，2013，65(5-8)：881-893.
[17] A，KARABULUT ?. Dynamic chip breaker design for Inconel 718 using positive angle tool holder [J]. Materials and Manufacturing Processes，2008，23(8)：852-857.
[18] KOMANDURI R，VON TURKOVICH B F. New observations on the mechanism of chip formation when machining titanium alloys [J]. Wear，1981，69(2)：179-188.
[19] KOMANDURI R. Some clarifications on the mechanics of chip formation when machining titanium alloys [J]. Wear，1982，76(1)：15-34.
[20] TURLEY D M，DOYLE E D，RAMALINGAM S. Calculation of shear strains in chip formation in titanium [J]. Materials Science and Engineering，1982，55(1)：45-48.
[21] KOMANDURI R，SCHROEDER T A. On shear instability in machining a nickel-iron base superalloy [J]. Journal of Engineering for Industry，1986，108：93-100.
[22] DAVIES M A，CHOU Y，EVANS C J. On chip morphology，tool wear and cutting mechanics in finish hard turning [J]. CIRP Annals - Manufacturing Technology，1996，45(1)：77-82.
[23] ELBESTAWI M A，SRIVASTAVA A K，EL-WARDANY T I. A model for chip formation during machining of hardened steel [J]. CIRP Annals - Manufacturing Technology，1996，45(1)：71-6.
[24] KAMATA Y，OBIKAWA T. High speed MQL finish-turning of Inconel 718 with different coated tools [J]. Journal of Materials Processing Technology，2007，192-193：281-6.
[25] 文东辉，刘献礼，严复钢，等. PCBN刀具的磨损机理 [J]. 哈尔滨理工大学学报，2002，7(1)：56-59. WEN Donghui，LIU Xianli，YAN Fugang，et al. Wear mechanism of polycrystalline curbic boron nitride tools [J]. Journal of Harbin University of Science and Technology，2002，7(1)：56-59.
