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

Abstract

A surface-modified magnesium alloy thin-walled tube and its reverse extrusion die and preparation method. The thin-walled tube is composed of an Mg-Zn-Sr alloy tube and an anodized surface coating; the anodized surface coating is composed of magnesium silicate and magnesium oxide; reverse extrusion die: it consists of an upper die part and a lower die part. The upper die part includes an upper template and an extrusion rod; the lower die part includes a lower template, an extrusion barrel, an extrusion die and a mandrel. , an extrusion die is provided in the extrusion cylinder; preparation method: 1) Preheat the Mg‑Zn‑Sr alloy ingot and reversely extrude it using the reverse extrusion die to obtain the alloy pipe; 2) Pull the alloy pipe Pulling treatment is performed to obtain an alloy ultra-fine thin-walled tube; 3) The alloy ultra-fine thin-walled tube is used as an anode and the lead tube is used as a cathode, and electrolysis is performed to obtain a surface-modified Mg-Zn-Sr alloy ultra-fine thin-walled tube. The magnesium alloy ultra-fine thin-walled tube of the present invention has an elastic modulus of 41 to 50 GPa, a tensile strength of 270 to 300 MPa, an elongation of 9 to 14%, and a hardness of 55 to 60 HV.

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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