Abstract
Serrated chip formed in dry hard turning is considered one of the major chip types. In this paper, the main objective was to understand how the crack initiation and propagation, and thermo-plastic instability and pressure from force contribute to the formation mechanism of serrated chip in dry hard high-speed orthogonal turning (DHHOT) of the hardened steel with different hardness levels at cutting speed with 50, 450, and 850 m/min. The influences of the cutting speeds (50, 450, and 850 m/min) and workpiece hardness (40, 45, 50, 55, and 60 ± 1 Rockweel hardness (HRC)) on chip morphology, segment spacing, degree of segmentation, chip deformation coefficient, shear angle, and chip segmentation frequency also were experimentally investigated. Experimental results showed that the very high strain in the shear band does give rise to the high temperature in higher hardness material and at higher cutting speed and this makes the high-speed slip of the shear band much easier happen along existing micro-crack. The critical chip is produced at a cutting speed of 50 m/min and a hardness level of 50 ± 1 HRC. The strain rate increases with the increments of the cutting speed, which increases brittleness, and thus induces acceleration of the crack propagation speed in shear band. Moreover, the increments of the quenching hardness can increase the brittleness of the workpiece and thus lead to the large damage in shear band. The microstructure of the material within the bottom of chip showed that the elongated grains do appear due to thermo-mechanical effect between the chip back and the rake face of the cutting tool.
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Tang L, Gao C, Huang J, Shen H, Lin X (2006) Experimental investigation of surface integrity in finish dry hard turning of hardened tool steel at different hardness levels. J Adv Manuf Technol 77(9–12):1655–1669
Wan L, Wang DZ, Gao YY (2016) The investigation of mechanism of serrated chip formation under different cutting speeds. J Adv Manuf Technol 82(5–8):1655–1669
Poulachon AL, Moisan J (2000) Hard turning: chip formation mechanisms and metallurgical aspects. J Manuf Sci E-T ASME 122(3):406–412
Joshi SS, Ramakrishnan N, Ramakrishnan P (2001) Micro-structural analysis of chip formation during orthogonal machining of Al/SiCp composites. J Eng Mater Technol 123(3):315–321
Guo YB, Yen DW (2004) A FEM study on mechanisms of discontinuous chip formation in hard machining. J Mater Process Technol 155-156:1350–1356
Dolinšek S, Ekinović S, Kopač J (2004) A contribution to the understanding of chip formation mechanism in high-speed cutting of hardened steel. J Mater Process Technol 157-158:485–490
Shi J, Liu CR (2006) On predicting chip morphology and phase transformation in hard machining. J Adv Manuf Technol 27(7–8):645–654
Wan L, Wang DZ, Gao YY (2009) The investigation of mechanism of serrated chip formation under different cutting speeds. J Adv Manuf Technol 82(5–8):951–959
Zhang S, Guo YB (2009) An experimental and analytical analysis on chip morphology. Phase transformation, oxidation, and their relationships in finish hard milling. Int J Mach Tools Manuf 49(11):805–813
Su GS, Liu Z (2010) An experimental study on influences of material brittleness on chip morphology. J Adv Manuf Technol 51(1–4):87–92
Mhamdi MB, Ben Salem S, Boujelbene M, Bayraktar E (2013) Experimental study of the chip morphology in turning hardened AISI D2 steel. J Mech Sci Technol 27(11):3451–3461
Sutter G, List G (2013) Very high speed cutting of Ti-6A1-4V titanium alloy—change in morphology and mechanism of chip formation. Int J Mach Tools Manuf 66:37–43
Gu L, Wang M, Duan C (2013) On adiabatic shear localized fracture during serrated chip evolution in high speed machining of hardened AISI 1045 steel. Int J Mech Sci 75:288–298
Wang C, Xie Y, Zheng L, Qin Z, Tang D, Song Y (2014) Research on the chip formation mechanism during the high-speed milling of hardened steel. Int J Mach Tools Manuf 79:31–48
Zhang X, Shivpuri R, Srivastava AK (2016) Chip fracture behavior in the high speed machining of titanium alloys. J Manuf Sci E-T ASME 138(8):1–14
Nakayama K, Arai M, Kanda T (1998) Machining characteristics of hard materials. Ann CIRP 37(1):89–92
Yang Y, Li J (2010) Study on mechanism of chip formation during high-speed milling of alloy cast iron. J Adv Manuf Technol 46(1–4):1655–1669
Zhou A, Deng F (2001) Experimental study on the heat treatment process for Cr12MoV steel. Die Mould Ind 000(9):55–57
Wang LJ, Miao B, Meng XX (2005) Analysis on the hardness and metallographic structure of Cr12MoV steel under different heat treatment. Die Mould Ind 9:52–56
Liu Z, Wan Y, Zhou J (2006) Tool materials for high speed machining and their fabrication technologies. Mater Mech Eng 30(5):1–4
Schulz H, Abele E, Sahm A (2001) Material aspects of chip formation in HSC machining. CIRP Ann-Manuf Technol 50(1):45–48
Yang Q, Wu Liu YD (2016) Characteristics of serrated chip formation in high-speed machining of metallic materials. J Adv Manuf Technol 86(5–8):1201–1206
Vyas A, Shaw MC (1999) Mechanics of saw-tooth chip formation in metal cutting. J Manuf Sci E-T ASME 121(2):163–172
Barry J, Byrne G (2002) The mechanisms of chip formation in machining hardened steels. J Manuf Sci Eng 124(3):528–535
EI-Wardany T, Kishawy HA, EI-bestawi MA (2000) Surface integrity of die material in high speed hard machining. Part 1: micrographical analysis. J Manuf Sci E-T ASME 122 (4): 620–631.
Poulachon GR, Moisan AL, Jawahir IS (2007) Evaluation of chip morphology in hard turning using constitutive models and material property data. J Manuf Sci E-T ASME 129(1):41–47
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Tang, L., Yin, J., Sun, Y. et al. Chip formation mechanism in dry hard high-speed orthogonal turning of hardened AISI D2 tool steel with different hardness levels. Int J Adv Manuf Technol 93, 2341–2356 (2017). https://doi.org/10.1007/s00170-017-0667-5
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DOI: https://doi.org/10.1007/s00170-017-0667-5