Effect of Incremental Forming Parameters on Titanium Alloys Properties

Authors: Petr Homola, Lucie Novakova, Vaclav Kafka, Mariluz P. Oscoz

Abstract:

Shear spinning is closely related to the asymmetric incremental sheet forming (AISF) that could significantly reduce costs incurred by the fabrication of complex aeronautical components with a minimal environmental impact. The spinning experiments were carried out on commercially pure titanium (Ti-Gr2) and Ti-6Al-4V (Ti-Gr5) alloy. Three forming modes were used to characterize the titanium alloys properties from the point of view of different spinning parameters. The structure and properties of the materials were assessed by means of metallographic analyses and microhardness measurements. The highest value wall angle failure limit was achieved using spinning parameters mode for both materials. The feed rate effect was observed only in the samples from the Ti-Gr2 material, when a refinement of the grain microstructure with lower feed rate and higher tangential speed occurred. Ti-Gr5 alloy exhibited a decrease of the microhardness at higher straining due to recovery processes.

Keywords: Incremental forming, metallography, shear spinning, titanium alloys.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1336528

References:

[1] M. J. Donachie, Titanium–a technical guide. 2nd ed., ASM,2000, ch. 1.
[2] I. J. Polmear, Light Alloys – from traditional alloys to nanocrystals. 4th ed., Elsevier, 2006, ch. 1.
[3] M. Niinomi, "Mechanical properties of biomedical titanium alloys,” Mater. Sci. Eng., vol. A243, pp. 231–236, March 1998.
[4] Z. Okazaki et al., "Cytocompatibility of various metals and development of new titanium alloys for medical implants,” Mater. Sci. Eng., vol. A243, pp. 250–256, March 1998.
[5] W.C.Emmens, G. Sebastiani, and A.H. van den Boogaard, "The technology of Incremental Sheet Forming – A brief review of the history,” J. Mater. Process. Tech., vol. 201/8, pp. 981–997, June 2010.
[6] G. Hirt, et al., "Forming strategies and Process Modelling for CNC Incremental Sheet Forming,” CIRP Ann. Manuf. Technol., vol. 53, pp. 203–206, Jan. 2004.
[7] B.T. Araghi, et al., "Investigation into a new hybrid forming process: Incremental sheet forming combined with stretch forming,” CIRP Ann. Manuf. Technol., vol. 58, pp. 225–228, Jan. 2009.
[8] K. Jackson, and J. Allwood, "The mechanics of incremental sheet forming,” J.Mater. Process. Tech., vol. 209, pp. 1158–1174, Feb. 2009.
[9] J. Jeswiet, "Asymmetric Incremental Sheet Forming,” Adv. Mater. Res., vol. 6-8, pp. 35–58, May. 2005.
[10] Z. Liu, Y. Li, and P.A. Meehan, "Experimental investigation of mechanical properties, formability and force measurement for AA7075-O aluminum alloy sheets formed by incremental forming,” Int.J.Precis. Eng. Manuf., vol. 14, pp. 1891–1899, Nov. 2013.
[11] Q. Zhang et al., "Influence of anisotropy of the magnesium alloy AZ31 sheets on warm negative incremental forming,”J. Mater. Process. Tech., vol. 209, pp. 5514–5520, Jan.
[12] F.J. Humphreys, and M. Hatherly,: Recrystallization and Related Annealing Phenomena. 2nd ed., Elsevier, 2004, ch. 2.