Pure titanium two-step plastic deformation processing method

Abstract

The invention relates to a pure titanium two-step plastic deformation processing method in the technical field of metallic material plastic deformation; the method comprises the following steps: level-3 industrial pure titanium block is taken as the raw material, after being coated with graphite lubricant, the material is extruded on a 300KN hydraulic pressure universal experimental machine and then is subjected to rolling treatment at liquid nitrogen temperature to carry out deformation treatment on submicron crystal industrially pure titanium block, thus obtaining the superfine crystal pure titanium. The superfine crystal pure titanium of the invention features a tensile strength of 1218MPa and a specific elongation of 12.6%.

Description

technical field [0001] The invention relates to a processing method in the technical field of plastic deformation of metal materials, in particular to a two-step plastic deformation processing method for pure titanium. Background technique [0002] In recent years, the development of biomedical materials has attracted more and more attention from all over the world. Among biomedical materials, metal materials are the earliest to be used, mainly used to repair bones, joints, teeth, and blood vessels. Currently used in biomedical materials are mainly stainless steel, titanium and titanium alloys. Titanium has certain strength and high plasticity, and the σ of high-purity titanium b =300MPa, δ=40%, small density (4.51g / cm 3 ), the melting point is (1663±10)°C, and it has excellent corrosion resistance and heat resistance. At the same time, titanium is a non-magnetic metal and will not be magnetized in a large magnetic field. Titanium and its alloys also have an elastic modu...

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Problems solved by technology

[0005] A literature search of the prior art found that S.L.Semiatin and D.P.Delo, etc. had published a paper on "The ECAE Process of Difficult-to-work Alloys" in "Materials and Design" (Equal channel angularextrusion of difficult-to-work alloys , Materials and Design 21(2000) 311-322), this paper carried out the ECAE process on hard-to-deform metals such as pure Ti, Ti-6Al-4V and 4340 steel, the author of this paper used a mold with a channel angle of 90°, The temperature range of 25°C to 325°C and the strain rate of 0.002 / S to 2 / S were selected to carry out the ECAE process on pure titanium. As a result, pure titanium is very sensitive to the shear localization in the ECAE process. At room temperature (25°C) When using any strain rate between 0.002 / S and 2 / S, the pure titanium will become fragments after the ECAE process; while at other temperatures (125°C to 325°C) when trying to perform the ECAE process on pure titanium However, due to the influence of factors such as extrusion temperature, strain rate, and unsuitable lubrication conditions, pure titanium will also be fractured to varying degrees after ECAE, so it is impossible to obtain large bulk fine-grained materials.