Mechanical behaviour of pressed and sintered CP Ti and Ti–6Al–7Nb alloy obtained from master alloy addition powder

Abstract

The Ti-6Al-7Nb alloy was obtained using the blending elemental approach with a master alloy and elemental titanium powders. Both the elemental titanium and the Ti-6Al-7Nb powders were characterised using X-ray diffraction, differential thermal analysis and dilatometry. The powders were processed using the conventional powder metallurgy route that includes uniaxial pressing and sintering. The trend of the relative density with the sintering temperature and the microstructural evolution of the materials sintered at different temperatures were analysed using scanning electron microscopy and X-ray diffraction. A minimum sintering temperature of 1200ºC has to be used to ensure the homogenisation of the alloying elements and to obtain a pore structure composed of spherical pores. The sintered samples achieve relative density values that are typical for powder metallurgy titanium and no intermetallic phases were detected. Mechanical properties comparable to those specified for wrought Ti-6Al-7Nb medical devices are normally obtained. Therefore, the produced materials are promising candidates for load bearing applications as implant materials.

A STUDY ON MECHANICAL, TRIBOLOGICAL AND BIOLOGICAL CHARACTERISTICS OF TITANIUM HYDROXYAPATITE (Ti-HA) IMPLANTS

“…To keep the uniform concentration of the electrolyte, the magnetic stirring was controlled at a speed of 180 rpm. [6] Plasma spray coating HA coatings were applied to the grit-blasted gauge sections of cylindrical Ti-6Al-4V coupons in thicknesses of 25, 50, 75, 100 and 150mm. All coatings were deposited using identical atmospheric plasma-spray (APS) parameters by American Plasma-Spray Ltd. Dayton, Ohio, USA.…”

“…[PO 4 ]6 .5H 2 O) is a prominent calcium phosphate salts found in bone. But crystallographically hydroxyapatite (HA) is the dominant lattice structure of hard tissue.…”

Direct Laser Forming of Titanium Alloy Powders for Medical and Aerospace Applications

“…Ti-6Al-7Nb is a dedicated high strength titanium alloy with excellent biocompatibility for surgical implants. Used for replacement of hip joints, it has been in clinical use since early 1986 [17][18][19] . However, titanium and titanium alloys suffer from serious disadvantages of poor machining properties.…”

Comparison of Microstructure and Properties of Ti-6Al-7Nb Alloy Processed by Different Powder Metallurgy Routes

“…Using a sintering temperature of 1100ºC for the processing of the P&S Ti-6Al-7Nb samples leads to a much more homogeneous microstructure composed by alpha grains with an even distribution of α + β lamellae throughout the whole microstructure. Although the distribution of the alloying elements seems uniform and the diffusion processes completed, EDS analysis reveals that a minimum sintering temperature has to be used to guarantee that the alloying elements complete dissolve inside the titanium matrix [16]. When using a sintering temperature of 1100ºC the amount of residual porosity is still quite important as it can be clearly seen in Figure 5 c).…”