Surface-modified magnesium alloy thin-walled tube and its reverse extrusion die and preparation method

Abstract

The invention relates to a surface modified magnesium alloy thin walled pipe, and a backward extrusion die and a preparation method thereof. The thin walled pipe is formed by a Mg-Zn-Sr alloy pipe and an anodic oxidation surface coating; the anodic oxidation surface coating is formed by magnesium silicate and magnesium oxide; the backward extrusion die comprises an upper die part and a lower die part; the upper die part comprises an upper die plate and an extrusion rod; the lower die part comprises a lower die plate, an extrusion cylinder, an extrusion female die and a core rod; and the extrusion female die is arranged in the extrusion cylinder. The preparation method comprises the following steps of (1) preheating a Mg-Zn-Sr alloy ingot, and utilizing the backward extrusion die for backward extruding to obtain an alloy pipe; (2) drawing the alloy pipe to obtain an alloy ultra-fin thin walled pipe; (3) adopting the alloy ultra-fin thin walled pipe as an anode, and a lead pipe as a cathode, electrolyzing to obtain the surface modified Mg-Zn-Sr alloy ultra-fin thin walled pipe. According to the magnesium alloy thin walled pipe provided by the invention, the elasticity modulus is ranged from 41 to 50GPa, the tensile strength is ranged from 270 to 300MPa, the ductility is ranged from 9 to 14 percent, and the hardness is ranged from 55 to 60HV.

Description

technical field [0001] The invention belongs to the technical field of materials, and in particular relates to a medical surface-modified Mg-Zn-Sr alloy thin-walled tube, a reverse extrusion die and a preparation method thereof. Background technique [0002] Cardiovascular disease is the most threatening disease to human beings, and its morbidity and mortality rank first. Coronary artery stents are important materials for the treatment of cardiovascular diseases. With the aging of the population, the quality requirements are getting higher and higher, and the consumption is also increasing. The country with the highest incidence of cardiovascular diseases in the world is China. High-quality coronary stents need to be imported from abroad. Due to the high price of coronary artery stents, many ordinary people are turned away. Among the patients in China who need cardiovascular stent treatment, only 1% have received stent interventional treatment, and other patients have to ch...

AI Technical Summary

Problems solved by technology

Biodegradable polymer materials have better biocompatibility with the human body and less side effects, but they have problems such as low strength, rigidity and stability, especially when they cannot be developed under X-rays. obstacle

At present, although 316L stainless steel, cobalt-chromium alloy, nickel-titanium shape memory alloy, etc. have been clinically applied, they have the following shortcomings and problems: ① Electrolytic corrosion and poor biocompatibility

Traditional metal materials are prone to electrolytic corrosion in the human environment, and the corrosion will release toxic ions, causing adverse reactions such as allergic reactions and inflammation in the body

②It is prone to reocclusion after operation

Traditional metal stents cannot be degraded and absorbed by the human body in clinical application. After the stent is implanted in the vascular lesion, it will remain in the vessel wall for a long time, which is not conducive to the late reconstruction of the diseased vessel, and may cause elastic recoil of the vessel, intimal damage, Thrombosis, vascular intima and smooth muscle hyperplasia, the incidence of restenosis as high as 10% to 20% after surgery seriously reduces the long-term efficacy, and the treatment of stent implantation cannot be performed again after restenosis

③ high cost

Relatively tight resources, high preparation and processing costs make the cost of implant materials such as 316L stainless steel, cobalt-chromium alloy, nickel-titanium shape memory alloy high, which greatly increases the economic burden of patients

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