In this study, a mesoscale dislocation simulation method was developed to study the orthogonal cutting of titanium alloy. The evolution of surface grain structure and its effects on the surface mechanical properties were studied by using two-dimensional climb assisted dislocation dynamics technology. The motions of edge dislocations such as dislocation nucleation, junction, interaction with obstacles, and grain boundaries, and annihilation were tracked. The results indicated that the machined surface has a microstructure composed of refined grains. The fine-grains bring appreciable scale effect and a mass of dislocations are piled up in the grain boundaries and persistent slip bands. In particular, dislocation climb can induce a perfect softening effect, but this effect is significantly weakened when grain size is less than 1.65 μm. In addition, a Hall–Petch type relation was predicted according to the arrangement of grain, the range of grain sizes and the distribution of dislocations.
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D. Ulutan and T. Ozel: Machining induced surface integrity in titanium and nickel alloys: A review. Int. J. Mach. Tool. Manufact. 51 (3), 250–280 (2011).
R. M’Saoubi, J.C. Outeiro, H. Chandrasekaran, O.W. Dillon, and I.S. Jawahir: A review of surface integrity in machining and its impact on functional performance and life of machined products. Int. J. Sustain. Manufact. 1 (1–2), 203–206 (2008).
I.S. Jawahir, E. Brinksmeier, R. M’Saoubi, D.K. Aspinwall, J.C. Outeiro, D. Meyer, D. Umbrello, and A.D. Jayal: Surface integrity in material removal process: Recent advances. CIRP Ann. 60 (2), 603–626 (2011).
M.A. Hadi, J.A. Ghani, and C.H. Haron: Effect of cutting speed on the carbide cutting tool in milling Inconel 718 alloy. J. Mater. Res. 31 (13), 1885–1892 (2016).
M.R. Shankar, S. Lee, and S. Chandrasekhar: Severe plastic deformation (SPD) of titanium at near-ambient temperature. Acta Mater. 54 (14), 3691–3700 (2006).
S. Swaminathan, M.R. Shankar, S. Lee, J.H. Huang, A.H. King, R.F. Kezar, B.C. Rao, T.L. Brown, S. Chandrasekar, W.D. Compton, and K.P. Trumble: Large strain deformation and ultra-fine grained materials by machining. Mater. Sci. Eng., A 410 (12), 358–363 (2015).
E. Brinksmeier, R. Gläbe, and J. Osmer: Ultra-precision diamond cutting of steel molds. CIRP Ann. 55 (1), 551–554 (2006).
S. Wang, S. To, C.Y. Chan, C.F. Cheung, and W.B. Lee: A study of the cutting-induced heating effect on the machined surface in ultra-precision raster milling of 6061 Al alloy. Int. J. Adv. Manuf. Tech. 51 (1–4), 69–78 (2010).
S.J. Zhang, S. To, C.F. Cheung, and Y. Zhu: Micro-structural changes of aluminum alloy influencing micro-topographical surface in micro-cutting. Int. J. Adv. Manuf. Tech. 72 (1–4), 9–15 (2014).
D.W. Schwach and Y.B. Guo: A fundamental study on the impact of surface integrity by hard turning on rolling contact fatigue. Int. J. Fatigue. 28 (12), 1838–1844 (2006).
A. Ramesh, S.N. Melkote, L.F. Allard, L. Riester, and T.R. Watkins: Analysis of white layers formed in hard turning of 52100 steels. Mater. Sci. Eng., A 390 (1–2), 88–97 (2015).
V.M. Fedirko, O.H. LukYanenko, and V.S. Trush: Influence of the diffusion saturation with oxygen on the durability and long-term static strength of titanium alloys. Mater. Sci. 50 (3), 415–420 (2014).
H.T. Ding and Y.C. Shin: Multi-physics modeling and simulations of surface microstructure alteration in hard turning. J. Mater. Process. Technol. 213 (6), 877–886 (2013).
R. Liu, M. Salahshoor, S.N. Melkote, and T. Marusich: A unified material mode including dislocation drag and its application to simulation of orthogonal cutting of OFGC copper. J. Mater. Process. Technol. 216, 328–338 (2015).
S.S. Shishvan and E. Van der Giessen: Mode I crack analysis in single crystals with anisotropic discrete dislocation plasticity: I. Formation and crack growth. Modell. Simul. Mater. Sci. Eng. 21 (21), 1163–1166 (2013).
E. Tarleton, D.S. Balint, J. Gong, and A.J. Wilkinson: A discrete dislocation plasticity study of the micro-cantilever size effect. Acta Mater. 88, 271–282 (2015).
Y.L. Liao, Y. Chang, H. Gao, and B.J. Kim: Dislocation pinning effects induced by nano-precipitates during warm laser shock peening: Dislocation dynamic simulation and experiments. J. Appl. Phys. 110 (023518), 1–7 (2011).
V. Giessen and E. Needleman: Discrete dislocation plasticity: A simple planar model. Modell. Simul. Mater. Sci. Eng. 3 (3), 689–735 (1995).
M.S. Huang, Z.H. Li, and J. Tong: The influence of dislocation climb on the mechanical behavior of polycrystals and grain size effect at elevated temperature. Int. J. Plasticity 61, 112–127 (2014).
K. Danas and V.S. Deshpande: Plane-strain discrete dislocation plasticity with climb-assisted glide motion of dislocations. Modell. Simul. Mater. Sci. Eng. 21 (4), 45008–45033 (2013).
C. Ayas, V.S. Deshpande, and M.G.D. Geers: Tensile response of passivated films with climb-assisted dislocation glide. J. Mech. Phys. Solids 60 (9), 1626–1643 (2012).
K.M. Davoudi, L. Nicola, and J.J. Vlassak: Dislocation climb in two-dimensional discrete dislocation dynamics. J. Appl. Phys. 111 (10), 103522 (2012).
A.A. Benzerga, Y. Brechet, A. Needleman, and V. Giessen: Incorporating three-dimensional mechanisms into two-dimension dislocation dynamics. Modell. Simul. Mater. Sci. Eng. 12 (3), 159–196 (2004).
Y.C. Zhang, T. Mabrouki, D. Nelias, and Y.D. Gong: Chip formation in orthogonal cutting considering interface limiting shear stress and damage evolution based on fracture energy approach. Finite Elem. Anal. Des. 47 (7), 850–863 (2011).
R.K. Al-Rub and G.Z. Voyiadjis: A physical based gradient plasticity theory. Int. J. Plasticity 22 (4), 654–684 (2006).
J.Z. Lu, K.Y. Luo, Y.K. Zhang, C.Y. Cui, G.F. Sun, J.Z. Zhou, L. Zhang, J. You, K.M. Chen, and J.W. Zhong: Grain refinement of LY12 aluminum alloy induced by ultra-high plastic strain during multiple laser shock processing impacts. Acta Mater. 58 (11), 3984–3994 (2010).
A. Ginting and M. Nouari: Surface integrity of dry machined titanium alloys. Int. J. Mach. Tool. Manufact. 49 (3–4), 325–332 (2009).
G.D. Hughes, S.D. Smith, C.S. Pande, H.R. Johnson, and R.W. Armstrong: Hall–Petch strengthening for the micro hardness of twelve nanometer grain diameter electrodeposited nickel. Scr. Mater. 20 (1), 93–97 (1986).
R. Liu, M. Salahshoor, and S.N. Melkote: A unified material model including dislocation drag and its application to simulation of orthogonal cutting of OFHC Copper. J. Mater. Process. Technol. 216, 328–338 (2015).
Z.H. Li, C.T. Hou, M.S. Huang, and C.J. Ouyang: Strengthening mechanism in micro-polycrystals with penetrable grain boundaries by discrete dislocation dynamics simulation and Hall–Petch effect. Comput. Mater. Sci. 46 (4), 1124–1134 (2009).
Q.Q. Wang, Z.Q. Liu, and B. Wang: Evolutions of grain size and micro-hardness during chip formation and machined surface generation for Ti–6Al–4V in high-speed machining. Int. J. Adv. Manuf. Tech. 82 (9–12), 1725–1736 (2016).
G. Rotella and D. Umbrello: Finite element modeling of microstructural changes in dry and cryogenic cutting of Ti6Al4V alloy. CIRP Ann. 63 (1), 69–72 (2014).
N. Ahmed and A. Hartmaier: Mechanisms of grain boundary softening and strain-rate sensitivity in deformation of ultrafine-grained metals at high temperatures. Acta Mater. 59 (11), 4323–4334 (2011).
N. Ahmed and A. Hartmaier: A two-dimensional dislocation dynamics model of the plastic deformation of polycrystalline metals. J. Mech. Phys. Solids 58 (12), 2054–2064 (2010).
R. Sedlacek: Internal stresses in dislocation wall structures. Scr. Mater. 33 (2), 283–288 (1995).
J.S. Kim, J.H. Kim, and Y.T. Lee: Microstructural analysis on boundary sliding and its accommodation mode during superplastic deformation of Ti–6Al–4V alloy. Mater. Sci. Eng., A 263 (2), 272–280 (1999).
W.D. Nix, J.R. Greer, G. Feng, and E.T. Lileodden: Deformation at the nanometer and micrometer length scales: Effects of strain gradients and dislocation starvation. Thin Solid Films 515 (6), 3152–3157 (2007).
L.P. Evers, W.A.M. Brekelmans, and M.G.D. Geers: Scale dependent crystal plasticity framework with dislocation density and grain boundary effects. Int. J. Solids Struct. 41 (18–19), 5209–5230 (2004).
U. Borg: A strain gradient crystal plasticity analysis of grain size effects in polycrystals. Eur. J. Mech. A-Solid 26 (2), 313–324 (2007).
D.B. Balint and V.S. Deshpande: Discrete dislocation plasticity analysis of the grain size dependence of the flow strength of polycrystals. Int. J. Plasticity 24 (12), 2149–2172 (2008).
This research work was jointly supported by the National Natural Science Foundation of China (Grant No. 51575138) and the State Key Program of National Natural Science Foundation of China (Grant No. 51535003).
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Bai, J., Bai, Q., Tong, Z. et al. Evolution of surface grain structure and mechanical properties in orthogonal cutting of titanium alloy. Journal of Materials Research 31, 3919–3929 (2016). https://doi.org/10.1557/jmr.2016.444