Study of the Effect of the Floating Die Compaction on Mechanical Properties of Titanium Foams

Abstract

Titanium (Ti) and its alloys are used for biomedical applications because of their high resistance to corrosion, good strength-to-weight ratio, and high fatigue resistance. However, a problem that compromises the performance of the material is the mismatch between Young’s modulus of Ti and the bone, which brings about stress shielding. One strategy that has been investigated to reduce this difference is the manufacture of Ti-based foams, using powder metallurgy (PM) methods, such as the space-holder technique. However, in the uniaxial compaction, both non-uniform density distribution and mechanical properties remain because of the compaction method. This work studies the influence of compaction by adopting a floating-action die related to a single-action die (SAD), on the density of green and sintered Ti foams with porosities around 50 vol.% characterized by optical microscopy, ultrasound analysis, compression tests, and microhardness. The compaction process employing a floating-action die generates Ti foams with a higher density up to 10% with more control of the spacer particle added compared to the single-action die. Furthermore, compaction method has no relevant effect on microhardness and Young’s modulus, which allows getting better consolidated samples with elastic modules similar to those of human bone.

Effect of the Processing Parameters on the Porosity and Mechanical Behavior of Titanium Samples with Bimodal Microstructure Produced via Hot Pressing

“…Among the manufacturing processes employed to obtain porous metallic materials are tied freeze casting [ 7 , 8 ], selective laser melting (SLM) [ 9 , 10 ], field assisted sintering (FAST) [ 11 , 12 ], and powder metallurgy [ 13 , 14 ]. Powder metallurgy, in combination with the space-holder technique, represents a cost-effective and flexible way to obtain components with a high-degree of porosity (35–80%) and a homogeneous distribution of pores throughout the volume [ 15 , 16 , 17 ].…”