Abstract
Saw tooth chip is a typical characteristic encountered in high-speed machining. It consists of nearly undeformed segments and highly sheared concentrated shear bands. However, no consensus on the formation of the concentrated shear band has been reached though several saw tooth chip formation models have been built. In this paper, the concentrated shear band formation procedure is analyzed based on a new proposed saw tooth chip formation model. Cutting experiments have been conducted to validate the proposed mode. It shows that the plastic side flow and elastic compression of the uncut chip are crucial for the concentrated shear band formation. The localized shear at the inner end (tool tip side) of the primary shear plane firstly takes place under the indentation of cutting tool. Then, the second localized shear is produced at the outer end (free surface side) of the primary shear plane due to stress concentration there, after which the whole concentrated shear band forms. The stress transition at the outer end of the primary shear plane makes the second localized shear easier evolve into cracks. Influences of material brittleness and cutting speed on initiation and propagation of the concentrated shear band are also analyzed.
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References
Childs THC, Maekawa K, Obikawa T, Yamane Y (2000) Metal machining: theory and applications. Arnold, London
Schulz H (2001) Scientific fundamentals of HSC. Carl Hanser, München
Su G, Liu Z (2010) An experimental study on influences of material brittleness on chip morphology. Int J Adv Manuf Technol 51:87–92
Shaw MC, Vyas A (1993) Chip formation in the machining of hardened steel. CIRP Ann 42(1):29–33
Turley DM, Doyle ED (1982) Calculation of shear strains in chip formation in titanium. Mater Sci Eng 55:45–48
Manyindo BM, Oxley PLB (1986) Modeling the catastrophic shear type of chip when machining stainless steel. Proc Instn Mech Engrs 200:349–358
Hou ZB, Komanduri R (1995) On a thermomechanical model of shear instability in machining. CIRP Ann 44(1):69–73
Astakahov VP (2006) Tribology of metal cutting. Elsevier, New York
Shaw MC, Vyas A (1998) The mechanisms of chip formation with hard turning steel. CIRP Ann 47(1):77–82
Joshi SS, Ramakrishnan N, Ramakrishnan P (2001) Micro-structural analysis of chip formation during orthogonal machining of AI/SiCp composites. J Eng Mater Technol 123:315–321
Shivpuri R, Hua J, Mittal P, Srivastava A (2002) Microstructure-mechanics interactions in modeling chip segmentation during titanium machining. CIRP Ann 51:71–74
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
Bäker M (2006) Finite element simulation of high-speed cutting forces. J Mater Process Technol 176:117–126
Calamaz M, Coupard D, Nouari M, Girot F (2011) Numerical analysis of chip formation and shear localization processes in machining the Ti-6Al-4 V titanium alloy. Int J Adv Manuf Technol 52:887–895
Lorentzon J, Järvsträt N, Josefson BL (2009) Modeling chip formation of alloy 718. J Mater Process Technol 209:4645–4653
Komanduri R, Hou ZB (2002) On thermoplastic shear instability in the machining of a titanium alloy (Ti6Al4V). Metall Mater Trans A 33(9):2995–3010
Oxley PLB (1989) Mechanics of machining: an analytical approach to assessing machinability. Ellis Horwood, Chichister
Fernández-Abia AI, Barreiro J, López de Lacalle LN, Martínez S (2011) Effect of very high cutting speeds on shearing, cutting forces and roughness in dry turning of austenitic stainless steels. Int J Adv Manuf Technol 57:61–71
Buda J (1972) New methods in the study of plastic deformation in the cutting zone. CIRP Ann 21:17–18
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
Yan J, Yoshino M, Kuriagawa T, Shirakashi T, Syoji K, Komanduri R (2001) On the ductile machining of silicon for micro electro-mechanical system (MEMS), opto-electronic and optical applications. Mater Sci Eng A 297:230–234
Liu K, Li XP, Liang SY (2007) The mechanism of ductile chip formation in cutting of brittle materials. Int J Adv Manuf Technol 33:875–884
Meyers MA (1994) Dynamic behavior of materials. Wiley, New York
Armstrong RW, Walley SM (2008) High strain rate properties of metals and alloys. Int Mater Rev 53(3):105–128
Liu Z, Su G (2012) Characteristics of chip evolution with elevating cutting speed from low to very high. Int J Mach Tool and Manu 54–55:82–85
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Su, G., Liu, Z. Analytical and experimental study on formation of concentrated shear band of saw tooth chip in high-speed machining. Int J Adv Manuf Technol 65, 1735–1740 (2013). https://doi.org/10.1007/s00170-012-4295-9
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DOI: https://doi.org/10.1007/s00170-012-4295-9