Sintering method of titanium or titanium alloy powder. The technical scheme of the invention is as follows: a sintering method for titanium or titanium alloy powder comprises the following steps: 1) preparing powder; 2) the heating body heats the powder; 3) Electromagnetic field heating the powder. The sintering method of titanium or titanium alloy powder provided by the invention transmits heat to the titanium or titanium alloy powder in contact with the heating body, destroys and dissolves the non-conductive titanium dioxide oxide layer on the surface of the titanium or titanium alloy powder in the contact layer, makes the titanium or titanium alloy powder connect with each other and conducts electricity, realizes the rapid heating of the powder layer by layer under the action of alternating electromagnetic field, and finally obtains the complete sintered body. The method of the invention has the advantages of fast heating speed, short sintering time, reduced sintering body size and simple process, and can be used to prepare porous titanium or titanium alloy and fully dense titanium or titanium alloy sintered body with different pore gas rates. Titanium and titanium alloy due to their high specific strength, low modulus, excellent biocompatibility, corrosion resistance, as structural materials have been widely used in aerospace, automotive, diving, medical implants. Porous titanium and titanium alloys have high surface area and low modulus functional properties through the introduction of holes, extending the application of titanium and titanium alloys in orthopedic implant materials, battery electrode materials, sound absorption materials and filter materials. The pore structure of porous titanium can be divided into two types: closed cell structure and open cell structure. Closed cell structure porous titanium, due to its closed holes, so that it has high damping, sound absorption and heat insulation functions, mainly used in sound absorption materials, thermal protection materials. Porous titanium with open structure, due to the perforation between the holes, with closed cell structure porous titanium functional properties at the same time, both filter, mainly used in orthopedic implant materials, battery electrode materials, filter materials. At present, the preparation methods of porous titanium and titanium alloy are mainly traditional powder metallurgy technology, including powder loose sintering, adding pore-forming agent, organic foam dipping method, freeze casting, fiber sintering and so on. Including I.H.O h (,49,1197 ScriptaMaterialia, 2003), such as by spherical titanium powder vacuum sintering, preparation of the hole structure of pore gas rate 37% porous titanium, the young's modulus and bending strength close to the human body skeleton. anonukul et al. (Powder Technology,2014 266,129) selected polyamine foam to soak titanium powder by organic foam leaching method, and prepared 84% porous titanium with porosity through degrease and vacuum sintering, whose Young's modulus could reach 0.58GPa. As for the preparation technology of porous titanium, due to the dense titanium dioxide oxide film on the surface of titanium powder, the electron migration between the titanium powder in contact with each other is hindered, so that it cannot be sintered by rapid heating of electromagnetic field. Heat can only be conducted to the powder through the above heating elements for sintering under vacuum conditions, and the heating rate is slow and the heating time is longer, resulting in large shrinkage of the sintered body size. The size of the product is not easy to control, and it is not suitable for the preparation of porous titanium and titanium alloys with high porosity.
Tag: titanium
