Skip to main content Accessibility help
×
Home

Evolution of surface grain structure and mechanical properties in orthogonal cutting of titanium alloy

  • Jinxuan Bai (a1), Qingshun Bai (a1), Zhen Tong (a2), Chao Hu (a1) and Xin He (a1)...

Abstract

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.

Copyright

Corresponding author

a) Address all correspondence to these authors. e-mail: jinxuanbai@hit.edu.cn
b) e-mail: qshbai@hit.edu.cn

References

Hide All
1. Ulutan, D. and Ozel, T.: Machining induced surface integrity in titanium and nickel alloys: A review. Int. J. Mach. Tool. Manufact. 51(3), 250280 (2011).
2. M’Saoubi, R., Outeiro, J.C., Chandrasekaran, H., Dillon, O.W., and Jawahir, I.S.: 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), 203206 (2008).
3. Jawahir, I.S., Brinksmeier, E., M’Saoubi, R., Aspinwall, D.K., Outeiro, J.C., Meyer, D., Umbrello, D., and Jayal, A.D.: Surface integrity in material removal process: Recent advances. CIRP Ann. 60(2), 603626 (2011).
4. Hadi, M.A., Ghani, J.A., and Haron, C.H.: Effect of cutting speed on the carbide cutting tool in milling Inconel 718 alloy. J. Mater. Res. 31(13), 18851892 (2016).
5. Shankar, M.R., Lee, S., and Chandrasekhar, S.: Severe plastic deformation (SPD) of titanium at near-ambient temperature. Acta Mater. 54(14), 36913700 (2006).
6. Swaminathan, S., Shankar, M.R., Lee, S., Huang, J.H., King, A.H., Kezar, R.F., Rao, B.C., Brown, T.L., Chandrasekar, S., Compton, W.D., and Trumble, K.P.: Large strain deformation and ultra-fine grained materials by machining. Mater. Sci. Eng., A 410(12), 358363 (2015).
7. Brinksmeier, E., Gläbe, R., and Osmer, J.: Ultra-precision diamond cutting of steel molds. CIRP Ann. 55(1), 551554 (2006).
8. Wang, S., To, S., Chan, C.Y., Cheung, C.F., and Lee, W.B.: 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), 6978 (2010).
9. Zhang, S.J., To, S., Cheung, C.F., and Zhu, Y.: Micro-structural changes of aluminum alloy influencing micro-topographical surface in micro-cutting. Int. J. Adv. Manuf. Tech. 72(1–4), 915 (2014).
10. Schwach, D.W. and Guo, Y.B.: A fundamental study on the impact of surface integrity by hard turning on rolling contact fatigue. Int. J. Fatigue. 28(12), 18381844 (2006).
11. Ramesh, A., Melkote, S.N., Allard, L.F., Riester, L., and Watkins, T.R.: Analysis of white layers formed in hard turning of 52100 steels. Mater. Sci. Eng., A 390(1–2), 8897 (2015).
12. Fedirko, V.M., LukYanenko, O.H., and Trush, V.S.: Influence of the diffusion saturation with oxygen on the durability and long-term static strength of titanium alloys. Mater. Sci. 50(3), 415420 (2014).
13. Ding, H.T. and Shin, Y.C.: Multi-physics modeling and simulations of surface microstructure alteration in hard turning. J. Mater. Process. Technol. 213(6), 877886 (2013).
14. Liu, R., Salahshoor, M., Melkote, S.N., and Marusich, T.: A unified material mode including dislocation drag and its application to simulation of orthogonal cutting of OFGC copper. J. Mater. Process. Technol. 216, 328338 (2015).
15. Shishvan, S.S. and Van der Giessen, E.: Mode I crack analysis in single crystals with anisotropic discrete dislocation plasticity: I. Formation and crack growth. Modell. Simul. Mater. Sci. Eng. 21(21), 11631166 (2013).
16. Tarleton, E., Balint, D.S., Gong, J., and Wilkinson, A.J.: A discrete dislocation plasticity study of the micro-cantilever size effect. Acta Mater. 88, 271282 (2015).
17. Liao, Y.L., Chang, Y., Gao, H., and Kim, B.J.: Dislocation pinning effects induced by nano-precipitates during warm laser shock peening: Dislocation dynamic simulation and experiments. J. Appl. Phys. 110(023518), 17 (2011).
18. Giessen, V. and Needleman, E.: Discrete dislocation plasticity: A simple planar model. Modell. Simul. Mater. Sci. Eng. 3(3), 689735 (1995).
19. Huang, M.S., Li, Z.H., and Tong, J.: The influence of dislocation climb on the mechanical behavior of polycrystals and grain size effect at elevated temperature. Int. J. Plasticity 61, 112127 (2014).
20. Danas, K. and Deshpande, V.S.: Plane-strain discrete dislocation plasticity with climb-assisted glide motion of dislocations. Modell. Simul. Mater. Sci. Eng. 21(4), 4500845033 (2013).
21. Ayas, C., Deshpande, V.S., and Geers, M.G.D.: Tensile response of passivated films with climb-assisted dislocation glide. J. Mech. Phys. Solids 60(9), 16261643 (2012).
22. Davoudi, K.M., Nicola, L., and Vlassak, J.J.: Dislocation climb in two-dimensional discrete dislocation dynamics. J. Appl. Phys. 111(10), 103522 (2012).
23. Benzerga, A.A., Brechet, Y., Needleman, A., and Giessen, V.: Incorporating three-dimensional mechanisms into two-dimension dislocation dynamics. Modell. Simul. Mater. Sci. Eng. 12(3), 159196 (2004).
24. Zhang, Y.C., Mabrouki, T., Nelias, D., and Gong, Y.D.: Chip formation in orthogonal cutting considering interface limiting shear stress and damage evolution based on fracture energy approach. Finite Elem. Anal. Des. 47(7), 850863 (2011).
25. Al-Rub, R.K. and Voyiadjis, G.Z.: A physical based gradient plasticity theory. Int. J. Plasticity 22(4), 654684 (2006).
26. Lu, J.Z., Luo, K.Y., Zhang, Y.K., Cui, C.Y., Sun, G.F., Zhou, J.Z., Zhang, L., You, J., Chen, K.M., and Zhong, J.W.: Grain refinement of LY12 aluminum alloy induced by ultra-high plastic strain during multiple laser shock processing impacts. Acta Mater. 58(11), 39843994 (2010).
27. Ginting, A. and Nouari, M.: Surface integrity of dry machined titanium alloys. Int. J. Mach. Tool. Manufact. 49(3–4), 325332 (2009).
28. Hughes, G.D., Smith, S.D., Pande, C.S., Johnson, H.R., and Armstrong, R.W.: Hall–Petch strengthening for the micro hardness of twelve nanometer grain diameter electrodeposited nickel. Scr. Mater. 20(1), 9397 (1986).
29. Liu, R., Salahshoor, M., and Melkote, S.N.: A unified material model including dislocation drag and its application to simulation of orthogonal cutting of OFHC Copper. J. Mater. Process. Technol. 216, 328338 (2015).
30. Li, Z.H., Hou, C.T., Huang, M.S., and Ouyang, C.J.: Strengthening mechanism in micro-polycrystals with penetrable grain boundaries by discrete dislocation dynamics simulation and Hall–Petch effect. Comput. Mater. Sci. 46(4), 11241134 (2009).
31. Wang, Q.Q., Liu, Z.Q., and Wang, B.: 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), 17251736 (2016).
32. Rotella, G. and Umbrello, D.: Finite element modeling of microstructural changes in dry and cryogenic cutting of Ti6Al4V alloy. CIRP Ann. 63(1), 6972 (2014).
33. Ahmed, N. and Hartmaier, A.: Mechanisms of grain boundary softening and strain-rate sensitivity in deformation of ultrafine-grained metals at high temperatures. Acta Mater. 59(11), 43234334 (2011).
34. Ahmed, N. and Hartmaier, A.: A two-dimensional dislocation dynamics model of the plastic deformation of polycrystalline metals. J. Mech. Phys. Solids 58(12), 20542064 (2010).
35. Sedlacek, R.: Internal stresses in dislocation wall structures. Scr. Mater. 33(2), 283288 (1995).
36. Kim, J.S., Kim, J.H., and Lee, Y.T.: Microstructural analysis on boundary sliding and its accommodation mode during superplastic deformation of Ti–6Al–4V alloy. Mater. Sci. Eng., A 263(2), 272280 (1999).
37. Nix, W.D., Greer, J.R., Feng, G., and Lileodden, E.T.: Deformation at the nanometer and micrometer length scales: Effects of strain gradients and dislocation starvation. Thin Solid Films 515(6), 31523157 (2007).
38. Evers, L.P., Brekelmans, W.A.M., and Geers, M.G.D.: Scale dependent crystal plasticity framework with dislocation density and grain boundary effects. Int. J. Solids Struct. 41(18–19), 52095230 (2004).
39. Borg, U.: A strain gradient crystal plasticity analysis of grain size effects in polycrystals. Eur. J. Mech. A-Solid 26(2), 313324 (2007).
40. Balint, D.B. and Deshpande, V.S.: Discrete dislocation plasticity analysis of the grain size dependence of the flow strength of polycrystals. Int. J. Plasticity 24(12), 21492172 (2008).

Keywords

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed