Prediction model of surface integrity characteristics in ball end milling TC17 titanium alloy

Abstract

Surface integrity is important to improve the fatigue property of components. Proper selection of the cutting parameters is extremely important in ensuring high surface integrity. In this paper, ball end milling of TC17 alloy has been carried out utilizing response surface methodology. The effects of cutting speed, feed per tooth, cutting depth, and cutting width on the surface integrity characteristics, including surface roughness (R _a), surface topography, residual stress, and microstructure were examined. Moreover, predictive metamodels for surface roughness, residual stress, and microhardness as a function of milling parameters were proposed. According to the experimental results obtained, the surface roughness increases with the increase of milling parameters, the (R _a) values vary from 0.4 μm to 1.2 μm along the feed direction, which are much lower compared to that along the pick feed direction. The surface compressive residual stress increases with the increase of feed per tooth, cutting depth, and cutting width, while that decreases at high cutting speed. The depth of the compressive residual stress layer is mostly in the range of 25–40 μm. The milled surface microhardness represents 6.4% compared with the initial state; the work-hardened layer depth is approximately 20 μm. Moreover, plastic deformation and strain streamlines are observed within 3 μm depth beneath the surface. The empirical model of surface integrity characteristics is developed using the results of ten experiments and validated by two extra experiments. The prediction errors of the three surface integrity characteristics are within 27%; the empirical model of microhardness has the lowest prediction errors.

Keywords

Prediction model / Surface roughness (R _a) / Residual stress / Microhardness / Microstructure

References

[1] Wang HT, Fang ZZ, Sun P. A critical review of mechanical properties of powder metallurgy titanium. Int J Powder Metall, 2010, 46(5): 45-57.

[2] Pimenov DY, Mia M, Gupta MK, et al. Improvement of machinability of Ti and its alloys using cooling-lubrication techniques: a review and future prospect. J Mater Res Technol, 2021, 11: 719-753.

[3] Gupta K, Laubscher RF. Sustainable machining of titanium alloys: a critical review. Proc IMechE Part B J Eng Manuf, 2017, 231: 1-18.

[4] Wang C. High temperature deformation behavior of TC17 alloy. Mater Sci Appl, 2018, 9(9): 732-739.

[5] Wang MJ, Huang H, Li SQ, et al. Microstructural difference between unreinforced canning of TC17 alloy and the matrix in SiCf/TC17 composite fabricated by HIP process. Mater Sci Forum, 2016, 849: 402-408.

[6] Jamil M, Zhao W, He N, et al. Sustainable milling of Ti-6Al-4V: a trade-off between energy efficiency, carbon emissions and machining characteristics under MQL and cryogenic environment. J Clean Prod, 2021, 281.

[7] Che-Haron CH, Jawaid A. The effect of machining on surface integrity of titanium alloy Ti-6%Al-4%V. J Mater Process Technol, 2005, 166(2): 188-192.

[8] Yang XY, Ren CZ, Wang Y, et al. Experimental study on surface integrity of Ti-6Al-4V in high speed side milling. Trans Tianjin Univ, 2012, 18(3): 206-212.

[9] Hassanpour H, Rasti A, Sadeghi MH, et al. Investigation of roughness, topography, microhardness, white layer and surface chemical composition in high speed milling of Ti-6Al-4V using minimum quantity lubrication. Mach Sci Technol, 2020, 24(5): 719-738.

[10] Yao CF, Wu DX, Jin QC, et al. Influence of high-speed milling parameter on 3D surface topography and fatigue behavior of TB6 titanium alloy. Trans Nonferr Metal Soc, 2013, 23(3): 650-660.

[11] Liu JY, Sun JF, Chen WY. Surface integrity of TB6 titanium alloy after dry milling with solid carbide cutters of different geometry. Int J Adv Manuf Technol, 2017, 92(3): 4183-4198.

[12] Yang D, Liu ZQ. Surface topography analysis and cutting parameters optimization for peripheral milling titanium alloy Ti-6Al-4V. Int J Refract Met H, 2015, 51: 192-200.

[13] Weber D, Kirsch B, Chighizola CR, et al. Analysis of machining-induced residual stresses of milled aluminum workpieces, their repeatability, and their resulting distortion. Int J Adv Manuf Technol, 2021, 115(1/4): 1-22.

[14] Nespor D, Denkena B, Grove T, et al. Differences and similarities between the induced residual stresses after ball end milling and orthogonal cutting of Ti-6Al-4V. J Mater Process Technol, 2015, 226: 15-24.

[15] Yang D, Xiao X, Liu YL, et al. Peripheral milling-induced residual stress and its effect on tensile-tensile fatigue life of aeronautic titanium alloy Ti-6Al-4V. Aeronaut J, 2019, 123(1260): 212-229.

[16] Shen XH, Zhang DH, Yao CF, et al. Formation mechanism of surface metamorphic layer and influence rule on milling TC17 titanium alloy. Int J Adv Manuf Technol, 2021, 112(6): 1-18.

[17] Yue CX, Hao XL, Ji X, et al. Analytical prediction of residual stress in the machined surface during milling. Metals, 2020, 10(4): 498-518.

[18] Li X, Wang ZM, Yang SL, et al. Influence of turning tool wear on the surface integrity and anti-fatigue behavior of Ti1023. Adv Mech Eng, 2021, 13(4): 1-12.

[19] Sun J, Guo YB. A comprehensive experimental study on surface integrity by end milling Ti-6Al-4V. J Mater Process Technol, 2009, 209(8): 4036-4042.

[20] Oosthuizen AG, Nunco K, Conradie JTP, et al. The effect of cutting parameters on surface integrity in milling Ti6Al4V. S Afr J Ind Eng, 2016, 27: 115-123.

[21] Safari H, Sharif S, Izman S, et al. Surface integrity characterization in high-speed dry end milling of Ti-6Al-4V titanium alloy. Int J Adv Manuf Technol, 2015, 78(1): 651-657.

[22] Velásquez JDP, Tidu A, Bolle B, et al. Sub-surface and surface analysis of high speed machined Ti-6Al-4V alloy. Mater Sci Eng A-Struct, 2010, 527(10/11): 2572-2578.

[23] Liang XL, Liu ZQ, Wang B. Dynamic recrystallization characterization in Ti-6Al-4V machined surface layer with process-microstructure-property correlations. Appl Surf Sci, 2020, 530: 147184.

[24] Wang QQ, Liu ZQ, Wang B, et al. 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 Technol, 2016, 82(9/12): 1725-1736.

[25] Li BX, Zhang S, Li JF, et al. Quantitative evaluation of mechanical properties of machined surface layer using automated ball indentation technique. Mater Sci Eng A-Struct, 2020, 773(31): 138717.

[26] Patil S, Jadhav S, Kekade S, et al. The influence of cutting heat on the surface integrity during machining of titanium alloy Ti6Al4V. Procedia Manuf, 2016, 5: 857-869.

[27] Yao CF, Wu DX, Ma LF, et al. Surface integrity evolution and fatigue evaluation after milling mode, shot-peening and polishing mode for TB6 titanium alloy. Appl Surf Sci, 2016, 387(30): 1257-1264.

[28] Sun JF, Wang TM, Su AP, et al. Surface integrity and its influence on fatigue life when turning nickel alloy GH4169. Procedia CIRP, 2018, 71: 478-483.

[29] De Los RER, Trull M, Levers A. Modelling fatigue crack growth in shot-peened components of Al 2024–T351. Fatigue Fract Eng Mater, 2000, 23(8): 709-716.

[30] Nie XF, He WF, Zang SL, et al. Effect study and application to improve high cycle fatigue resistance of TC11 titanium alloy by laser shock peening with multiple impacts. Surf Coat Technol, 2014, 253: 68-75.

[31] Zuo JH, Wang ZG, Han EH. Effect of microstructure on ultra-high cycle fatigue behavior of Ti-6Al-4V. Mater Sci Eng A-Struct, 2008, 473(1/2): 147-152.

[32] Hultgren G, Mansour R, Barsoum Z, et al. Fatigue probability model for AWJ-cut steel including surface roughness and residual stress. J Constr Steel Res, 2021, 179(2021): 106537.

[33] Shen XH, Zhang DH, Tan L. Effects of cutter path orientations on milling force, temperature, and surface integrity when ball end milling of TC17 alloy. Proc IMechE Part B J Eng Manuf, 2020, 235(6/7): 1212-1224.

[34] UNE-EN 15305-2010 (2010) Non-destructive testing - test method for residual stress analysis by X-ray diffraction. The Spanish Association for Standardization and Certification

[35] Tan L, Zhang DH, Yao CF, et al. Evolution and empirical modeling of compressive residual stress profile after milling, polishing and shot peening for TC17 alloy. J Manuf Process, 2017, 26: 155-165.

[36] Wang LP, Ge SY, Si H, et al. Elliptical model for surface topography prediction in five-axis flank milling. Chin J Aeronaut, 2020, 33(4): 1361-1374.

[37] Shan CW, Zhang X, Shen B, et al. An improved analytical model of cutting temperature in orthogonal cutting of Ti6Al4V. Chin J Aeronaut, 2019, 156(03): 217-227.

[38] Swaminathan S, Shankar MR, Lee S, et al. Large strain deformation and ultra-fine grained materials by machining. Mater Sci Eng A-Struct, 2005, 410(12): 358-363.

[39] Zhou Z, Yao CF, Zhao Y, et al. Effect of ultrasonic impact treatment on the surface integrity of nickel alloy 718. Adv Manuf, 2021, 9(1): 160-171.

Funding

National Natural Science Foundation of China http://dx.doi.org/10.13039/501100001809(92160301)

National Science and Technology Major Project of China(2017-VII-0001-0094)