EFFECTS OF POSITIONING CONDITIONS ON MATERIAL PROPERTIES IN POWDER BED FUSION ADDITIVE MANUFACTURING

Öz

Among additive manufacturing technologies, Powder Bed Fusion (PBF) is considered the most common process. Although the PBF has many advantages, some issues must be clarified, such as positioning. In this study, the effect of positioning on the microstructures in the PBF method was investigated. Ti6Al4V samples were manufacutred in different positions on the building platform and investigated by means of temperature, porosity, microstructure and hardness. In this study, martensitic needles were detected on the microstructure samples. Some twins were noticed on primary martensitic lines and the agglomeration of β precipitates was observed in vanadium-rich areas. The positioning of samples were revealed to have an effect on temperature gradients and the average martensitic line dimensions. Besides, different hardness values were attained depending on sample positioning conditions. As a major result, cooling rates were found related to the positions of samples and the location of points on the samples.

Anahtar Kelimeler

• Additive manufacturing
• selective laser melting
• Ti6Al4V
• thermal effect
• temperature distribution

Kaynakça

1. 1. Kayacan M.C., Delikanli Y.E., Duman B., Ozsoy K., “Examining of mechanical properties of transitive (variable) porous specimens produced by SLS using ti6Al4v alloy powder”, Journal of the Faculty of Engineering and Architecture of Gazi University,Vol. 33, Issue 1, Pages 127-143, 2018.
2. 2. Badiru A.B, Valencia V.V., Liu D., “Additive manufacturing handbook: product development for the defense industry”. CRC Press, 2017.
3. 3. Poprawe R, Hinke C., Meiners W., Schrage J., Bremen S., Merkt S., “SLM production systems: recent developments in process development, machine concepts and component design” Advances in Production Technology, Pages 49-65, 2015.
4. 4. Patterson A.E., Messimer S.L., Farrington P.A., “Overhanging features and the SLM/DMLS residual stresses problem: Review and future research need” Technologies, Vol. 5, Issue 2, Page 15, 2017.
5. 5. Arısoy Y.M, Criales, L.E, Özel T., Lane B., Moylan S., Donmez A., “Influence of scan strategy and process parameters on microstructure and its optimization in additively manufactured nickel alloy 625 via laser powder bed fusion” The International Journal of Advanced Manufacturing Technology, Vol. 90, Issue 5-8, Pages 1393-1417, 2017.
6. 6. Zhao C., Fezzaa K., Cunningham R.W., Wen H., De Carlo F., Chen L., Sun T., “Real-time monitoring of laser powder bed fusion process using high-speed X-ray imaging and diffraction” Scientific reports, Vol. 7, Issue 1, Pages 1-11, 2017.
7. 7. Ali H., Ma L., Ghadbeigi H., Mumtaz K., “In-situ residual stress reduction, martensitic decomposition and mechanical properties enhancement through high temperature powder bed pre-heating of Selective Laser Melted Ti6Al4V”. Materials Science and Engineering: A, Vol. 695, Pages 211-220, 2017.
8. 8. Li C., Liu Z.Y., Fang X.Y., Guo Y.B., “Residual stress in metal additive manufacturing” Procedia CIRP, Vol. 71, Pages 348-353, 2018.

9. 9. Acharya R., Sharon J.A., Staroselsky A., “Prediction of microstructure in laser powder bed fusion process” Acta Materialia, Vol. 124, Pages 360-371, 2017.
10. 10. Murr L.E., Quinones S.A., Gaytan S.M., Lopez M.I., Rodela A., Martinez E.Y., Wicker R.B., “Microstructure and mechanical behavior of Ti–6Al–4V produced by rapid-layer manufacturing, for biomedical applications” Journal of the mechanical behavior of biomedical materials, Vo. l 2, Issue 1, Pages 20-32, 2009.
11. 11. Song B., Dong S., Zhang B., Liao H., Coddet, C. “Effects of processing parameters on microstructure and mechanical property of selective laser melted Ti6Al4V” Materials & Design, Vol. 35, Pages 120-125, 2012.
12. 12. Scharowsky T., Juechter V., Singer R.F., Körner C., “Influence of the scanning strategy on the microstructure and mechanical properties in selective electron beam melting of Ti–6Al–4V” Advanced Engineering Materials, Vol. 17, Issue 11, Pages 1573-1578, 2015.
13. 13. Yadroitsev I., Krakhmalev, P., Yadroitsava I., Du Plessis A., “Qualification of Ti6Al4V ELI alloy produced by laser powder bed fusion for biomedical applications”. JOM, Vol .70, Issue 3, Pages 372-377, 2018.
14. 14. Yadroitsev I., Krakhmalev P., Yadroitsava I., “Selective laser melting of Ti6Al4V alloy for biomedical applications: Temperature monitoring and microstructural evolution” Journal of Alloys and Compounds, Vol. 583, Pages 404-409, 2014.
15. 15. Rafi H.K., Karthik N.V., Gong H., Starr T.L., Stucker B.E., “Microstructures and mechanical properties of Ti6Al4V parts fabricated by selective laser melting and electron beam melting”. Journal of materials engineering and performance, Vol. 22, Issue 12, Pages 3872-3883, 2013.
16. 16. Shipley H., McDonnell D., Culleton M., Coull R., Lupoi R., O'Donnell G., Trimble , D., “Optimisation of process parameters to address fundamental challenges during selective laser melting of Ti-6Al-4V: A review” International Journal of Machine Tools and Manufacture, Vol. 128, Pages 1-20, 2018.
17. 17. Galarraga H., Lados D.A., Dehoff R.R., Kirka M.M., Nandwana, P., “Effects of the microstructure and porosity on properties of Ti-6Al-4V ELI alloy fabricated by electron beam melting (EBM)” Additive Manufacturing, Vol. 10, Pages 47-57, 2016.
18. 18. Yadroitsev I., Krakhmalev P., Yadroitsava I., “Selective laser melting of Ti6Al4V alloy for biomedical applications: Temperature monitoring and microstructural evolution” Journal of Alloys and Compounds, 583 404-409, 2014.
19. 19. Vrancken B., Thijs L., Kruth J.P., Van Humbeeck J., “Heat treatment of Ti6Al4V produced by Selective Laser Melting: Microstructure and mechanical properties” Journal of Alloys and Compounds, Vol. 541, Pages 177-185, 2012.
20. 20. Cao S., Chen Z., Lim C.V.S, Yang K., Jia Q., Jarvis T., Wu X., “Defect, microstructure, and mechanical property of Ti-6Al-4V alloy fabricated by high-power selective laser melting” JOM, Vol. 69, Issue 12, Pages 2684-2692, 2017.
21. 21. Yang J., Yu H., Yin J., Gao M., Wang Z., Zeng X., “Formation and control of martensite in Ti-6Al-4V alloy produced by selective laser melting” Materials & Design, Vol. 10, Pages 308-318, 2016.
22. 22. Karimi J., Suryanarayana C., Okulov I., Prashanth K.G., “Selective laser melting of Ti6Al4V: Effect of laser re-melting” Materials Science and Engineering: A, Vol. 805, Issue 140558, 2021.
23. 23. Phutela C., Aboulkhair N.T., Tuck C.J., Ashcroft I., “The effects of feature sizes in selectively laser melted Ti-6Al-4V parts on the validity of optimised process parameters” Materials, Vol. 13, Issue 1, Page 117, 2020.
24. 24. Kayacan M.C., Delikanlı Y.E., Duman B., Özsoy K., “Ti6Al4V toz alaşımı kullanılarak SLS ile üretilen geçişli (değişken) gözenekli numunelerin mekanik özelliklerinin incelenmesi” Gazi Üniversitesi Mühendislik-Mimarlık Fakültesi Dergisi, Vol. 33, Issue 1, 2018.
25. 25. Rafi H.K., Karthik N.V., Gong H., Starr T.L., Stucker B.E., “Microstructures and mechanical properties of Ti6Al4V parts fabricated by selective laser melting and electron beam melting” Journal of materials engineering and performance, Vol. 22, Issue 12, Pages 3872-3883, 2013.
26. 26. ASTM E92-17: Standard test methods Standard Test Methods for Vickers Hardness and Knoop Hardness of Metallic Materials.
27. 27. Dunbar A.J., Denlinger E.R., Gouge M.F., Simpson T.W., Michaleris P., “Comparisons of laser powder bed fusion additive manufacturing builds through experimental in situ distortion and temperature measurements” Additive Manufacturing, Vol. 15, Pages 57-65, 2017.
28. 28. Criales L.E., Özel T., “Temperature profile and melt depth in laser powder bed fusion of Ti-6Al-4V titanium alloy” Progress in Additive Manufacturing, Vol. 2, Issue 3, Pages 169-177, 2017.
29. 29. Zhuang J.R., Lee Y.T., Hsieh W.H., Yang A.S., “Determination of melt pool dimensions using DOE-FEM and RSM with process window during SLM of Ti6Al4V powder” Optics & Laser Technology, Vol. 103, Pages 59-76, 2018.
30. 30. Van Hooreweder B., Moens D., Boonen R., Kruth J.P., Sas P., “Analysis of fracture toughness and crack propagation of Ti6Al4V produced by selective laser melting” Advanced Engineering Materials, Vol. 14, Issue 1‐2, Pages 92-97, 2012.
31. 31. Shutov I.V., Gordeev G.A., Kharanzhevskiy E.V., Krivilyov M.D., “Analysis of morphology and residual porosity in selective laser melting of Fe powders using single track experiments” IOP Conference Series: Materials Science and Engineering, Vol. 192, 2017.
32. 32. Ferrar B., Mullen L., Jones E., Stam R., Sutcliffe C.J., “Gas flow effects on selective laser melting (SLM) manufacturing performance” Journal of Materials Processing Technology, Vol. 21, Issue 2, Pages 355-364, 2012.
33. 33. Fousová M., Vojtěch D., Kubásek J., Jablonská E., Fojt J., “Promising characteristics of gradient porosity Ti-6Al-4V alloy prepared by SLM process” Journal of the mechanical behavior of biomedical materials, Vol. 69, Pages 368-376, 2017.
34. 34. Kasperovich G., Haubrich J., Gussone J., Requena G., “Correlation between porosity and processing parameters in TiAl6V4 produced by selective laser melting” Materials & Design, Vol. 105, Pages 160-170, 2016.
35. 35. Vrancken B., Thijs L., Kruth J.P., Van Humbeeck J., “Heat treatment of Ti6Al4V produced by Selective Laser Melting: Microstructure and mechanical properties” Journal of Alloys and Compounds, Vol. 541, Pages 177-185, 2012.
36. 36. Thijs L., Verhaeghe F., Craeghs T., Van Humbeeck J., Kruth J.P., “A study of the microstructural evolution during selective laser melting of Ti–6Al–4V”. Acta materialia, Vol. 58, Issue 9, Pages 3303-3312, 2010.
37. 37. Agius D., Kourousis K.I., Wallbrink C., Song T., “Cyclic plasticity and microstructure of as-built SLM Ti-6Al-4V: The effect of build orientation” Materials Science and Engineering: A, Vol. 70185, Issue 100, 2017.
38. 38. Tao P., Li H.X., Huang B.Y., Hu Q.D., Gong S.L., Xu Q.Y., “Tensile behavior of Ti-6Al-4V alloy fabricated by selective laser melting: Effects of microstructures and as-built surface quality” China Foundry, Vol. 15, Issue 4, Pages 243-252, 2018.
39. 39. Khorasani A., Gibson I., Awan U.S., Ghaderi A., “The effect of SLM process parameters on density, hardness, tensile strength and surface quality of Ti-6Al-4V”Additive Manufacturing, Vol. 25, Pages 176-186, 2019.
40. 40. Wang D., Dou W., Yang Y., “Research on selective laser melting of Ti6Al4V: Surface morphologies, optimized processing zone, and ductility improvement mechanism” Metals, Vol. 8, Issue 7, Page 471, 2018.