Effect of Aging on Microstructure and Tensile Properties of ASTM F75 Co-based Alloy Containing Different Carbon Contents

Subject Areas : Heat Treatment

shahin Torkamani ¹ , Masumeh Seifollahi ² , Maryam Morakabati ³ , Adli Akhondzadeh ⁴

1 -
2 -
3 -
4 -

Received: 2024-02-06 Accepted : 2024-04-19 Published : 2023-08-01

Keywords: Co-Cr-Mo based alloy, aging, microstructure, carbide, tensile strength,

Abstract :

This study aims to investigate the effect of aging on microstructural evolution and mechanical properties of two ASTM F75 alloys, one without the carbon additive and the other one containing 0.21 wt.% C. Aging on the samples solution-annealed at 1225 °C for 1 hour was performed at 720, 760, and 800°C for 5 hours. The evaluation of the microstructure of both samples after aging showed that the γ→ε transformation led to the formation of two various morphologies of the precipitates in the regions of the ε-phase. At the first stages of aging, the precipitates appeared as a series of straight bands in both samples, while with an increase in the temperature, pearlite-like regions were found at the grain boundaries of only the carbon-containing sample. In the sample without the carbon additive, the microstructure consisted of the σ-phase. In the carbon-containing sample, lamellar M₂₃C₆ carbides were formed during aging in the vicinity of the remaining blocky M₂₃C₆ carbides. The carbon-containing sample consisted of fine M₂₃C₆ carbides after aging at 720°C, which were distributed inside the grains and at the grain boundaries. The appropriate precipitation rate and their optimum distribution in the structure led to an increase in the yield strength by up to 15%, along with an increase in the ultimate tensile strength by up to 6% compared with the as-cast state. However, no significant improvement was found in the ductility of the alloy. 

References:

[1] J. B. Park, K. H. Jung, K. M. Kim, Y. Son, J. I. Lee, & J. H. Ryu, Microstructure of as-cast Co-Cr-Mo alloy prepared by investment casting, Journal of the Korean Physical Society, 72, 2018, 947-951.‏
https://doi.org/10.3938/jkps.72.947
[2] R. Silva, M. D. Santos, R. Madureira, et al., Scratch and wear behavior of Co-Cr-Mo alloy in ringer’s lactate solution, Materials 16, 2023, 2923.
https://doi.org/10.3390/ma16072923
[3] S. Mohammad Moradi, Sh. Zanganeh, Sh. Vardak, R. Bahrami, New Co-Cr-Mo-Nb-Cu alloy for implant applications: properties and chrachterization, Journal of alloys and Compound, 925, 2022, 166387.
https://doi.org/10.1016/j.jallcom.2022.166387
[4] Y. Li, Y. Yamashita, N. Tang, B. Liu, S. Kurosu, H. Matsumoto, & A. Chiba, Influence of carbon and nitrogen addition on microstructure and hot deformation behavior of biomedical Co–Cr–Mo alloy, Materials Chemistry and Physics, 135, 2012, 849-854.‏
https://doi.org/10.1016/j.matchemphys.2012.05.069
[5] L. E. R. Vidaurri, M. C. Roman, M. H. Trejo, K.L. F. Chavez, Secondary dendritic arm spacing and cooling rate relationship for an ASTM F75 alloy, Journal of Materials Research and Technology, 19, 2022, 5049-5065.
https://doi.org/10.1016/j.jmrt.2022.06.146
[6] A. Mani, & H. F. Lopez, Deformation induced FCC to HCP transformation in a Co–27Cr–5Mo–0.05 C alloy, Materials Science and Engineering: A, 528, 2011, 3037-3043.‏
https://doi.org/10.1016/j.msea.2010.12.024
[7] S. Mineta, S. Namba, T. Yoneda, K. Ueda, & T. Narushima, Precipitates in as-cast and heat-treated ASTM F75 Co-Cr-Mo-C alloys containing Si and/or Mn, Metallurgical and Materials Transactions A, 42, 2011, 1941-1949.
https://doi.org/10.1007/s11661-011-0604-4
[8] S. Mineta, S. Namba, T. Yoneda, K. Ueda, & T. Narushima, Changes in microstructure of biomedical Co-Cr-Mo-C alloys with solution treating and aging, Advanced Materials Research, 89, 2010, 377-382 .
https://doi.org/10.4028/www.scientific.net%2FAMR.89-91.377
[9] S. H. Lee, N. Nomura, & A. Chiba, Significant improvement in mechanical properties of biomedical Co-Cr-Mo alloys with combination of N addition and Cr-enrichment, Materials transactions, 2008, 0801150296-0801150296.‏
https://doi.org/10.2320/matertrans.MRA2007220
[10] M. Chauhan, Microstructural characterization of cobalt chromium (ASTM F75) cubes produced by EBM technique (Master's thesis), 2017.
[11] K. Ozturak, O. Ertugrul, M. Ozcan, Effect of various heat treatments on microstructure and mechanical properties of investment cast Co-Cr-Mo implants, Cumhriyet Science Journal, 42, 2021, 965-976.
https://doi.org/10.1016/j.msea.2022.143380
[12] J. V. Giacchi, O. Fornaro, and H. Palacio, Microstructural evolution during solution treatment of Co–Cr–Mo–C biocompatible alloys, Materials characterization, 68, 2012, 49-57.
https://doi.org/10.1016/j.matchar.2012.03.006
[13] H.Wang, T. Miyagi, A. Chilba, Effect of multiple reverse transformation treatment on grain refinement and mechanical properties of biomedical Co-Cr-Mo-N alloys fabricated by electron beam melting, Materials 16, 2023, 6528.
https://doi.org/10.3390/ma16196528
[14] S. H. Lee, E. Takahashi, N. Nomura, & A. Chiba, Effect of heat treatment on microstructure and mechanical properties of Ni-and C-free Co–Cr–Mo alloys for medical applications, Journal of the Japan Institute of Metals and Materials, 46, 2005, 1790-1793.
https://doi.org/ 10.2320/matertrans.46.1790
[15] S. H. Lee, E. Takahashi, N. Nomura, & A. Chiba, Effect of carbon addition on microstructure and mechanical properties of a wrought Co–Cr–Mo implant alloy, Materials transactions, 47, 2006, 287-290.‏
https://doi.org/ 10.2320/matertrans.47.287
[16] H. S. Dobbs, & J. L. M. Robertson, Heat treatment of cast Co-Cr-Mo for orthopaedic implant use, Journal of Materials Science, 18, 1983, 391-401.
https://doi.org/10.1007/BF00560627
[17] M. Herrera, A. Espinoza, J. Méndez, M. Castro, J. López, & J. Rendón, Effect of C content on the mechanical properties of solution treated as-cast ASTM F-75 alloys, Journal of Materials Science: Materials in Medicine, 16, 2005, 607-611.
https://doi.org/10.1007/s10856-005-2530-8 ‏
[18] ASTM F75-12, Standard Specification for Cobalt-28 Chromium-6 Molybdenum Alloy Castings and Casting Alloy for Surgical Implants (UNS R30075), West Conshohocken, PA: ASTM International, 2012.
[19] ASTM E8/E8M, Standard test methods for tension testing of metallic material, ASTM International, 2010.
[20] B. Geddes, H. Leon, & X. Huang, Superalloys: alloying and performance, Asm International, 2010.
[21] S. Zangeneh, E. Erisir, M. Abbasi, & A. Ramazani, Evaluation of the Aging Effect on the Microstructure of Co-28Cr-6Mo-0.3 C Alloy: Experimental Characterization and Computational Thermodynamics, Metals, 9, 2019, 581.
https://doi.org/10.3390/met9050581
[22] S. Zangeneh, H. R. Lashgari, M. Saghafi, & M. Karshenas, Effect of isothermal aging on the microstructural evolution of Co–Cr–Mo–C alloy, Materials Science and Engineering: A, 527(24-25), 2010, 6494-6500.
https://doi.org/10.1016/j.msea.2010.06.081
[23] D. McParland, S. Baron, S. O’Rourke, D. Dowling, E. Ahearne, & A. Parnell, Prediction of tool-wear in turning of medical grade cobalt chromium molybdenum alloy (ASTM F75) using non-parametric Bayesian models. Journal of Intelligent Manufacturing, 30, 2019, 1259-1270.
https://doi.org/10.1007/s10845-017-1317-3
[24] H. F. López, & A. J. Saldivar-Garcia, Martensitic transformation in a cast Co-CrMo-C alloy, Metallurgical and Materials Transactions A, 39, 2008,8-18.
https://doi.org/10.1007/s11661-007-9370-8