A simple and economical device to process Ti cylinders with elongated porosity by freeze-casting techniques: Design and manufacturing

Paloma Trueba Muñoz*, Joaquín R. Bascón Suárez, Ana M. Beltrán, José Antonio Rodriguez-Ortiz, Yadir Torres Hernández, Juan José Pavón Palacio, Esteban Alonso Álvarez, David C. Dunand

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Nowadays, the development of materials with gradient porosity is an important aim for many applications, especially in the field of bone tissue replacement. This research work shows the design and manufacture of a simple and economical device to process Ti cylinders with elongated and high interconnected porosity by freeze-casting techniques. The influence of the vessel material on the internal lamellar structure of the porous Ti samples is also studied. The device has been validated with: (i) a thermal gradient from -10 °C at the cold surface to 20 °C at the hot surface; and (ii) a cylindrical vessel with 12 mm diameter of alumina or Teflon. These working conditions have allowed maintaining the freezing conditions during the full process (alumina vessel: 30 minutes; Teflon vessel: 3 hours). After the solidification of the Ti aqueous suspension, the ice is sublimated (24 hours at -50 °C and 0.070 mbar). Then, the resulting powder is sintered (1150 °C for 5 h at high vacuum ~ 10-5 mbar), obtaining the porous Ti sample with the final structural strength. Finally, a detailed study of the most relevant porosity features is performed: porosity ratio and interconnectivity degree by Archimedes' method, and size and shape of the pores by image analysis at three different zones along the longitudinal cross section. The results indicate the viability of the device to enhance the directional freezing and thus, the elongated porosity. Teflon vessel present the best results, with an average porosity ratio and porosity size of 39.5 % and 123.3 µm, respectively. This suggests an optimal biomechanical and bifunctional balance of this porous material.

Original languageEnglish (US)
Title of host publicationTitanium Powder Metallurgy and Additive Manufacturing
EditorsMa Qian, Peng Cao, Huiping Tang, Gang Chen, Yong Liu
PublisherTrans Tech Publications Ltd
Pages255-261
Number of pages7
ISBN (Print)9783035711639
DOIs
StatePublished - Jan 1 2018
Event4th International Conference on Powder Metallurgy of Titanium, PMTi 2017 - Xian, China
Duration: Sep 8 2017Sep 10 2017

Publication series

NameKey Engineering Materials
Volume770 KEM
ISSN (Print)1013-9826

Other

Other4th International Conference on Powder Metallurgy of Titanium, PMTi 2017
CountryChina
CityXian
Period9/8/179/10/17

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Keywords

  • Freeze-casting technique
  • Gradient porosity
  • Porous titanium

ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

Cite this

Muñoz, P. T., Bascón Suárez, J. R., Beltrán, A. M., Rodriguez-Ortiz, J. A., Hernández, Y. T., Palacio, J. J. P., Álvarez, E. A., & Dunand, D. C. (2018). A simple and economical device to process Ti cylinders with elongated porosity by freeze-casting techniques: Design and manufacturing. In M. Qian, P. Cao, H. Tang, G. Chen, & Y. Liu (Eds.), Titanium Powder Metallurgy and Additive Manufacturing (pp. 255-261). (Key Engineering Materials; Vol. 770 KEM). Trans Tech Publications Ltd. https://doi.org/10.4028/www.scientific.net/KEM.770.255