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Chip formation mechanism in dry hard high-speed orthogonal turning of hardened AISI D2 tool steel with different hardness levels

  • Linhu Tang
  • Jun Yin
  • Yongji Sun
  • Hao Shen
  • Chengxiu Gao
ORIGINAL ARTICLE

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.

Keywords

Serrated chip Formation mechanism Crack Thermo-plastic instability Hardness Cutting speed 

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References

  1. 1.
    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):1655–1669Google Scholar
  2. 2.
    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):1655–1669Google Scholar
  3. 3.
    Poulachon AL, Moisan J (2000) Hard turning: chip formation mechanisms and metallurgical aspects. J Manuf Sci E-T ASME 122(3):406–412CrossRefGoogle Scholar
  4. 4.
    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):315–321CrossRefGoogle Scholar
  5. 5.
    Guo YB, Yen DW (2004) A FEM study on mechanisms of discontinuous chip formation in hard machining. J Mater Process Technol 155-156:1350–1356CrossRefGoogle Scholar
  6. 6.
    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 157-158:485–490CrossRefGoogle Scholar
  7. 7.
    Shi J, Liu CR (2006) On predicting chip morphology and phase transformation in hard machining. J Adv Manuf Technol 27(7–8):645–654CrossRefGoogle Scholar
  8. 8.
    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):951–959Google Scholar
  9. 9.
    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):805–813CrossRefGoogle Scholar
  10. 10.
    Su GS, Liu Z (2010) An experimental study on influences of material brittleness on chip morphology. J Adv Manuf Technol 51(1–4):87–92CrossRefGoogle Scholar
  11. 11.
    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):3451–3461CrossRefGoogle Scholar
  12. 12.
    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 66:37–43CrossRefGoogle Scholar
  13. 13.
    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 75:288–298CrossRefGoogle Scholar
  14. 14.
    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 79:31–48CrossRefGoogle Scholar
  15. 15.
    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):1–14CrossRefGoogle Scholar
  16. 16.
    Nakayama K, Arai M, Kanda T (1998) Machining characteristics of hard materials. Ann CIRP 37(1):89–92CrossRefGoogle Scholar
  17. 17.
    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):1655–1669Google Scholar
  18. 18.
    Zhou A, Deng F (2001) Experimental study on the heat treatment process for Cr12MoV steel. Die Mould Ind 000(9):55–57Google Scholar
  19. 19.
    Wang LJ, Miao B, Meng XX (2005) Analysis on the hardness and metallographic structure of Cr12MoV steel under different heat treatment. Die Mould Ind 9:52–56Google Scholar
  20. 20.
    Liu Z, Wan Y, Zhou J (2006) Tool materials for high speed machining and their fabrication technologies. Mater Mech Eng 30(5):1–4Google Scholar
  21. 21.
    Schulz H, Abele E, Sahm A (2001) Material aspects of chip formation in HSC machining. CIRP Ann-Manuf Technol 50(1):45–48CrossRefGoogle Scholar
  22. 22.
    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):1201–1206CrossRefGoogle Scholar
  23. 23.
    Vyas A, Shaw MC (1999) Mechanics of saw-tooth chip formation in metal cutting. J Manuf Sci E-T ASME 121(2):163–172CrossRefGoogle Scholar
  24. 24.
    Barry J, Byrne G (2002) The mechanisms of chip formation in machining hardened steels. J Manuf Sci Eng 124(3):528–535CrossRefGoogle Scholar
  25. 25.
    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.Google Scholar
  26. 26.
    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):41–47CrossRefGoogle Scholar

Copyright information

© Springer-Verlag London Ltd. 2017

Authors and Affiliations

  • Linhu Tang
    • 1
    • 2
    • 3
  • Jun Yin
    • 4
  • Yongji Sun
    • 1
    • 2
    • 3
  • Hao Shen
    • 4
  • Chengxiu Gao
    • 1
    • 2
    • 3
  1. 1.Provincial Key Laboratory for Green Cutting Technology and Application of Gansu Province (University)Lanzhou Institute of TechnologyLanzhouPeople’s Republic of China
  2. 2.College of Mechano-ElectronicLanzhou Institute of TechnologyLanzhouPeople’s Republic of China
  3. 3.LanzhouPeople’s Republic of China
  4. 4.College of Mechano-ElectronicLanzhou University of TechnologyLanzhouPeople’s Republic of China

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