Details

Autor(en) / Beteiligte

• Kashef, Sadaf
• Asgari, Alireza
• Hilditch, Timothy B.
• Yan, Wenyi
• Goel, Vijay K.
• Hodgson, Peter D.

Titel

Fatigue crack growth behavior of titanium foams for medical applications

Ist Teil von

• Materials science & engineering. A, Structural materials : properties, microstructure and processing, 2011-01, Vol.528 (3), p.1602-1607

Ort / Verlag

Kidlington: Elsevier B.V

Erscheinungsjahr

2011

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• ▶ Titanium foam with 60% porosity has higher Paris exponent than solid titanium. ▶ High Paris exponents are most likely caused by crack closure and crack bridging. ▶ Solid coating on titanium foam results in lower crack growth than uncoated foam. ▶ The load ratio had a negligible effect on the FCG behavior of both materials. ▶ Medical applications of titanium foams are not limited by their crack growth rate. There is an urgent need to understand the failure behavior of titanium foams because of their promising application as load-bearing implant materials in biomedical applications. Following our recent study on fracture toughness of titanium foams [1], this paper investigates the mode I fatigue crack propagation in 60% porous open pore titanium foams both with and without solid coated surface. Fatigue crack propagation tests were performed on compact tension specimens at load ratios of R=0.1 and R=0.5 and the fracture surfaces were examined using scanning electron microscopy. The crack growth rate, da/dN, versus the stress intensity factor range, ΔK, curves were measured and compared using two different techniques; image processing and compliance methods. The crack extension rates were well described by ΔK, using the Paris-power law approach. Coated and non-coated titanium foams with 60% porosity had a significantly higher Paris exponent than solid titanium, which can be explained by crack closure and crack bridging. It was also shown that the fatigue crack grows along the centerline, following the weakest path throughout the foam. The results obtained from this work provide important information for evaluating the structural integrity of porous titanium components in the future biomedical applications.