Abstract
Hard milling has the potential to replace finish grinding in manufacturing dies and molds. A significant impediment for wide-spread application of hard milling is the lack of understanding and control on the surface integrity of machined surface and subsurface. In this study, a Taguchi design-of-experiment based dry finish milling of AISI H13 tool steel (50 ± 1 HRc) with (Ti, Al) N/TiN coated cutting tools was conducted to investigate the process-induced surface integrity. The mechanism of surface integrity in hard milling was investigated to understand the effects of mechanical/thermal loads on surface microstructure and properties. The microstructure, microhardness and residual stresses were characterized. Phase transformation was not observed under the process parameters, while the increased microhardness and high compressive residual stresses obtained are beneficial for improving fatigue properties and wear resistance of the machined components. Finally, the process design space for the desired surface properties has been established via the microhardness and residual stress maps.
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Abbreviations
- a e :
-
Radial depth-of-cut (mm)
- a p :
-
Axial depth-of-cut (mm)
- f z :
-
Feed per tooth (mm/tooth)
- f n :
-
Feed per revolution (mm/tooth)
- v f :
-
Feed rate (mm/min)
- N :
-
Rotational speed of spindle (rev/min)
- n :
-
Number of the insert
- L f :
-
Cutting length in feed direction (mm)
- L s :
-
Cutting length in step-over direction (mm)
- N f :
-
Overlapping number of the tool locus in one cutting pass
- N s :
-
Overlapping number of the tool locus in step-over direction
References
Moshier M, Hillberry B (1999) The inclusion of compressive residual stress effects in crack growth modeling. Fatig Fract Eng Mater Struct 22:519–526
Toribio J (1998) Role of crack-tip residual stresses in stress corrosion behaviour of prestressing steel. Constr Build Mater 12:283–287
Schultz R, Karabin M (2002) Characterization of machining distortion by strain energy density and stress range. Mater Sci Forum 404–407:61–67
Guo Y, Warren A (2004) Microscale mechanical behavior of the subsurface by finishing processes. ASME J Manuf Sci Eng 127:333–338
Sasahara H (2005) The effect on fatigue life of residual stress and surface hardness resulting from different cutting conditions of 0.45% C steel. Int J Mach Tools Manuf 45:131–136
Viáfara C, Castro M, Vélez J, Toro A (2005) Unlubricated sliding wear of pearlitic and bainitic steels. Wear 259:405–411
Schwach D, Guo Y (2006) A fundamental study on the impact of surface integrity by hard turning on rolling contact fatigue. Int J Fatigue 28:1834–1844
Zarudi I, Zhang L (2002) Mechanical property improvement of quenchable steel by grinding. J Mater Sci 37:3935–3943
Axinte D, Dewes R (2002) Surface integrity of hot work tool steel after high speed milling-experimental data and empirical models. J Mater Process Technol 127:325–335
Marques M, Outeiro J, Dias A, Saoubi R, Chandrasekaran H (2006) Surface integrity of H13 ESR mould steel milled by carbide and CBN tools. Mater Sci Forum 514–516:564–568
Chen L, El-Wardany T, Nasr M, Elbestawi M (2006) Effects of edge preparation and feed when hard turning a hot work die steel with polycrystalline cubic boron nitride tools. CIRP Ann 55:89–92
König W, Klinger M, Link R (1990) Machining hard materials with geometrically defined cutting edges—field of applications and limitations. CIRP Ann 39:61–64
Töenshoff H, Wobker H, Brandt D (1995) Hard turning—influences on the workpiece properties. Trans NAMRI/SME 23:215–220
Liu M, Takag J, Tsukuda A (2004) Effect of tool nose radius and tool wear on residual stress distribution in hard turning of bearing steel. J Mater Process Technol 150:3234–3241
Warren A, Guo Y (2009) Characteristics of residual stress profiles in hard turned versus ground surfaces with and without a white layer. ASME J Manuf Sci Eng 131:1–10
Guo Y, Li W, Jawahir I (2009) Surface integrity characterization and prediction in machining of hardened and difficult-to-machine alloys: a state-of-art research review and analysis. Mach Sci Technol 13(4):437–470
Sharman A, Hughes J, Ridgway K (2004) Workpiece surface integrity and tool life issues when turning Inconel 718 nickel based superalloy. Mach Sci Technol 8:399–414
Akcan S, Shah S, Moylan S, Chhabra P, Chandrasekar S, Yang H (2002) Formation of white layers in steels by machining and their characteristics. Metall Mater Trans A 33:1245–1254
Elbestawi M, Chen L, Becze C, El-Wardany T (1997) High-speed milling of dies and molds in their hardened state. CIRP Ann 46:57–62
Guo Y, Janowski G (2004) Microstructural characterization of white layers by hard turning and grinding. Trans NAMRI/SME 34:367–374
Taguchi G (1993) Taguchi on robust technology development: bringing quality engineering upstream. ASME Press, New York
Warren A, Guo Y (2006) On the clarification of surface hardening mechanisms by hard turning and grinding. Trans. NAMRI/SME 34:309–316
Guo Y, Warren A, Hashimoto F (2010) The basic relationships between residual stress, white layer, and fatigue life of hard turned and ground surfaces in rolling contact. CIRP J Manuf Sci Technol 2:129–134
Acknowledgments
This research is based upon work supported by the National Science Foundation under Grant No. CMMI-0825780. The authors would like to thank Mrs. Rahul Waikar and Roberto Caslaru at The University of Alabama for help in sample preparation and characterization.
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S. Zhang is a visiting scholar at the Shandong University.
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Zhang, S., Li, W. & Guo, Y.B. Process design space for optimal surface integrity in finish hard milling of tool steel. Prod. Eng. Res. Devel. 6, 355–365 (2012). https://doi.org/10.1007/s11740-012-0387-5
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DOI: https://doi.org/10.1007/s11740-012-0387-5