Resources Recycling (자원리싸이클링)

The Korean Institute of Resources Recycling (한국자원리싸이클링학회)
권호 표지
DOI QR코드

DOI QR Code

Chipped Titanium Scraps as Raw Materials for Cutting Tools

타이타늄 밀링/터닝 스크랩의 절삭공구 소재화

  • Kwon, Hanjung (Division of Advanced Materials Engineering, College of Engineering, Jeonbuk National University) ;
  • Lim, Jae-Won (Division of Advanced Materials Engineering, College of Engineering, Jeonbuk National University)
  • 권한중 (전북대학교 신소재공학부) ;
  • 임재원 (전북대학교 신소재공학부)
  • Received : 2021.03.29
  • Accepted : 2021.04.14
  • Published : 2021.04.30
Download PDF
⟨ Previous Next ⟩

Abstract

Scraps are a byproduct of the machining process used for transforming titanium ingots into useful mechanical parts. Scraps take two forms, namely, bulky scraps, which are produced by cutting, and chipped scraps, which are produced by milling. Bulky scraps are comparatively easier to recycle because of their small surface area and less oxygen content; as a result, they pose only a small risk of explosion. In contrast, chipped scraps pose a higher risk of explosion, because of which, their recycling is complicated, resulting in most such scraps being discarded. With the aim of avoiding this waste, we proposed a novel process for converting chipped scraps into stable carbide materials. Methods typically applied to reduce particle size and impair the formation of solid solution type phase in the carbide materials were used to improve the mechanical properties of carbides prepared from chipped scraps. Our novel recycling process reduced carbide production costs and improved carbide quality.

밀링 및 터닝 가공 중 발생되는 칩 형태 타이타늄 스크랩을 세라믹스 원료로 활용하기 위한 연구를 수행하였다. 우선, 칩 형태 타이타늄 스크랩에 포함되어 있는 다량의 절삭유와 철 성분 제거를 위해 유기세정 및 산 세정 과정을 거쳐 스크랩 표면 세척을 진행하였다. 아세톤과 질산을 사용한 세정 과정을 통해 스크랩 내 유기물과 철 함량은 5 wt.% 수준에서 0.07 wt.% 이하로 감소하는 것을 확인하였고 세정에 이어진 산화 과정을 통해 타이타늄 스크랩은 이산화타이타늄화 되었다. 타이타늄 스크랩의 이산화타이타늄화 과정은 800 ℃ 이상의 온도에서 이루어졌으며 이산화타이타늄은 고에너지 밀링 과정을 통해 나노 결정립으로 미세화되어 탄소에 의한 환원 및 탄화 반응은 기존 이산화타이타늄 탄화환원 온도인 1500 ℃보다 낮은 1200 ℃에서 가능하게 되었다. 이산화타이타늄 탄화환원을 통해 얻어지는 타이타늄 탄화물은 질소 및 타이타늄 이외 전이금속 원소의 첨가 및 고용을 통해 물성이 개선될 수 있었다. 타이타늄 탄화물 내 질소 첨가 및 고용상 형성 가능성은 열역학 계산을 통해 예측되었고 질소 첨가 및 전이금속 고용에 의해 타이타늄 탄화물의 특성 중 경도 및 파괴인성 제어가 가능하였다.

Keywords

References

  1. Zheng H. and Okabe T.H., 2008 : Recovery of titanium metal scrap by utilizing chloride wastes, Journal of Alloys and Compounds, 461, pp.459-466. https://doi.org/10.1016/j.jallcom.2007.07.025
  2. Reitz J., Lochbichler C., Friedrich B., 2011: Recycling of gamma titanium aluminide scrap from investment casting operations, Intermetallics, 19, pp.762-768. https://doi.org/10.1016/j.intermet.2010.11.015
  3. Burkhard R., Hoffelner W., Eschenbach R. C., 1994 : Recycling of metals from waste with thermal plasma, Resources, Conservation and Recycling, 10, pp.11-16. https://doi.org/10.1016/0921-3449(94)90033-7
  4. Vutova K., Vassileva V., Koleva E., et al., 2010 : Investigation of electron beam melting and refining of titanium and tantalum scrap, Journal of Materials Processing Technology, 210, pp.1089-1094. https://doi.org/10.1016/j.jmatprotec.2010.02.020
  5. Sohn H.S. and Jung J.Y., 2016 : Current Status of Ilmenite Beneficiation Technology for Production of TiO2, Journal of Korean Institute of Resources Recycling, 25, pp.64-74. https://doi.org/10.7844/kirr.2016.25.5.64
  6. Sohn H.S. and Jung J.Y., 2016 : Current Status of Titanium Smelting Technology, Journal of Korean Institute of Resources Recycling, 25(4), pp.68-79. https://doi.org/10.7844/kirr.2016.25.4.68
  7. Sohn H.S., 2020 : Production Technology of Titanium by Kroll Process, Journal of Korean Institute of Resources Recycling, 29(4), pp.3-14. https://doi.org/10.7844/KIRR.2020.29.4.3
  8. Shon H.S., 2021 : Current Status of Titanium Recycling Technology, Resources Recycling, 30, pp.26-34. https://doi.org/10.7844/KIRR.2021.30.1.26
  9. White G.V., Mackenzie K.J.D., Brown I.W.M., et al., 1992 : Carbothermal synthesis of titanium nitride Part II The reaction sequence, Journal of Materials Science, 27, pp.4294-4299. https://doi.org/10.1007/BF00541555
  10. Koc R. and Folmer J.S., 1997 : Carbothermal synthesis of titanium carbide using ultrafine titania powders, Journal of Materials Science, 32, pp.3101-3111. https://doi.org/10.1023/A:1018634214088
  11. Berger L.M., Gruner W., Langholf E., et al., 1999 : On the mechanism of carbothermal reduction processes of TiO2 and ZrO2, International Journal of Refractory Metals and Hard Materials, 17, pp.235-243. https://doi.org/10.1016/S0263-4368(98)00077-8
  12. Gruner W., Stolle S., Wetzig K., et al., 2000 : Formation of COx species during the carbothermal reduction of oxides of Zr, Si, Ti, Cr, W, and Mo, International Journal of Refractory Metals and Hard Materials, 18, pp.137-145. https://doi.org/10.1016/S0263-4368(00)00013-5
  13. Woo Y.C., Kang H.J., Kim D.J., et al., 2007 : Formation of TiC particle during carbothermal reduction of TiO2, Journal of the European Ceramic Society, 27, pp.719-722. https://doi.org/10.1016/j.jeurceramsoc.2006.04.090
  14. Lee S.J. and Lee S.K., 2018 : Patent Strategy Establishment Report (Development of the commercialization Technology for manufacturing titanium carbonitride as a resource of cutting tool from titanium scraps), pp.8-14.
  15. Dedalus Consulting, 2014 : Cutting Tools; World markets, end-users, and competitors: 2012-2018 analysis & forecasts.
  16. Jung J. and Kang S., 2004 : Effect of ultra-fine powders on the microstructure of Ti(CN)-xWC-Ni cermets, Acta Materialia, 52, pp.1379-1386. https://doi.org/10.1016/j.actamat.2003.11.021
  17. Jung J. and Kang S., 2007 : Effect of Nano-Size Powders on the Microstructure of Ti(C,N)-xWC-Ni Cermets, Journal of the American Ceramic Society, 90, pp.2178-2183. https://doi.org/10.1111/j.1551-2916.2007.01654.x
  18. Jo H., Kwon H., Shon I.J., 2013 : Simultaneous Synthesis and Rapid Consolidation of Nanosctructured (Ti,Mo)C and Its Mechanical Properties, Korean Journal of Materials Research, 23, pp. 620-624. https://doi.org/10.3740/MRSK.2013.23.11.620
  19. Shon I., Suh C.Y., Lee S.J., et al., 2013 : Bulk (Ti,Cr)N consolidated by pulsed current activated sintering and its mechanical properties, Ceramics International, 39, pp.3441-3445.
  20. Kwon H., Kim J., Jung S.A., et al., 2014 : (Ti,W)C-Ni cermet prepared by high-energy ball milling and subsequent carbothermal reduction of TiO2-Ti-WO3-C mixture, Ceramics International, 40, pp.7607-7611. https://doi.org/10.1016/j.ceramint.2013.11.141
  21. Kwon H. and Jung S.A., 2014 : Solid Solution Cermet: (Ti,Nb)(CN)-Ni Cermets, Journal of Nanoscience and Nanotechnology, 14, pp.8823-8827. https://doi.org/10.1166/jnn.2014.9951
  22. Kwon H., Jung S.A., Suh C.Y., et al., 2014 : Mechanical properties of (Ti,V)C-Ni composite prepared using ultrafine solid-solution (Ti,V)C phase, Ceramics International, 40, pp.12579-12583. https://doi.org/10.1016/j.ceramint.2014.04.064
  23. Kwon H., Jung S.A., Kim W., 2015 : (Ti,Cr)C Synthesized In Situ by Spark Plasma Sintering of TiC/Cr3C2 Powder Mixtures, Materials Transactions, 56, pp.264-268. https://doi.org/10.2320/matertrans.M2014327
  24. Jung S.A., Kwon H., Roh K.M., et al., 2015 : Ti-based solid solution carbonitrides prepared from Ti-alloy scraps via a hydrogenation-dehydrogenation process and high-energy milling, Metals and Materials International, 21, pp.923-928. https://doi.org/10.1007/s12540-015-5050-1
  25. Oh J., Roh K.M., Kwon H., et al., 2015 : Preparation of Ti Ternary Alloys by Addition of Si to Ti-Mo Alloy Scraps for Carbonitride Application, Materials Trasactions, 56, pp.167-170. https://doi.org/10.2320/matertrans.M2014285