Low Young’s modulus Ti-based porous bulk glassy alloy without cytotoxic elements
Ti-based alloys are nowadays the standard solution for biomedical implants. However, both the conventional crystalline and amorphous alloys have higher rigidity as the human bone, leading to the damage of the bone at the interface, and contains harmful elements like vanadium, aluminum, nickel or beryllium. The hierarchical porous structures based on glassy alloys with biocompatible elements is a much better alternative. Our work presents for the first time the manufacturing of such porous bodies starting from Ti-based amorphous alloy ribbons, which contains only non-harmful elements. The new biocompatible Ti42Zr40Ta3Si15 (atomic %) porous bulk glassy alloy was produced by combination of rapid solidification and powder metallurgy techniques. Amorphous alloy ribbons were fabricated by melt spinning, i.e. extremely fast quenching the molten alloy with 106 K/s from T = 1973 K down to room temperature. The ribbons were then cryo-milled at liquid nitrogen temperature in order to produce powder, which was subsequently hot pressed. The resulting thick pellets have a porosity of about 14 vol.%, a high compression strength of 337 MPa and a Young’s modulus of about E = 52 GPa, values very close to those characteristic of cortical bone. Moreover, the morphology of the samples is very similar to that of cortical bone. The biocompatibility, which is due to the absence of any toxic element in the chemical composition, together with the suitable mechanical behavior, make these samples promising for orthopedic and dentistry applications.
Figure 1. SEM micrographs, SE mode, showing detailed appearance of the cross-section of the Ti42Zr40Ta3Si15 compacted pellets.
Figure 2. (a) Macroscopic appearance of a Ti42Zr40Ta3Si15 compacted pellet (cross-section, SEM, BSE). (b) Distribution of the pore dimensions and the corresponding fitting curve. (c) Cross-section of a human femur.
For further information contact:
Assoc. Prof. dr. habil. Mihai Stoica, IFW Dresden; e-mail: m.stioca(at)ifw-dresden.de
Assoc. Prof. Dr. Mircea Nicoara, UP Timisoara; e-mail: mnicoara(at)gmail.com