Method for preparing open-cell foam titanium

Abstract

The invention relates to a method for preparing open-cell foam titanium. The method includes 1) selecting high-purity titanium powder and needle-like urea to be mixed in a grinded body evenly to obtain initial mixture, wherein average grain diameter of the needle-like urea is 225-420 micrometers; 2) forming a cylindrical raw compact by the initial mixture; 3) performing two steps of hot processing on the raw compact, firstly, preheating the raw compact in a carbon tube furnace in a rough vacuum state of 10-1Pa to 10-2Pa, blowing out and cooling when heating temperature reaches above 460 DEG C, secondly, sintering the raw compact for 2 hours under a high-purity argon protective atmosphere at the temperature of 1250 DEG C, and finally, cooling the raw compact in the furnace to the room temperature to obtain the foam titanium. Two heating processes enable collapse not easy to occur during melting of the urea, and the titanium powder is not easy to carry away by melted urea liquid, so that output rate of the foam titanium is greatly increased when content of the urea serving as a pore forming agent is larger than 60% (volume fraction); in addition, two-time heating rate and temperature rate are properly selected to enable the urea to fully volatilize, and the titanium powder is free of contamination.

Description

technical field [0001] The invention relates to the technical field of foamed titanium materials, in particular to a method for preparing open-cell foamed titanium. Background technique [0002] In recent years, bone defect repair materials have become one of the biomedical materials with the greatest clinical demand. Traditional bone substitute materials are dense metals or alloys, such as cobalt-nickel alloys, stainless steel, titanium-based alloys, etc. Compared with other metals, titanium alloys have been widely used as bone substitute materials, mainly due to their low Young's modulus, corrosion resistance and good biocompatibility. However, compared with the bone with a porous structure, the dense titanium alloy scaffold is obviously not conducive to the ingrowth of new bone and the delivery of nutrients, which limits its service life in the human body. At the same time, although the mechanical properties of titanium alloys, especially the Young's modulus, can be re...

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Problems solved by technology

However, when M. Sharma used coarse (average particle size of 224 μm) acicular urea, titanium foam (with a porosity between 44-64%) almost completely formed a closed-cell structure, and when the content of the pore-forming agent exceeded 60% ( volume fraction), the green compact is prone to collapse and fracture during the urea removal process, and the yield of the final foamed titanium is less than 20%

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