Electron Beam Melting Forming Method for Magnesium Alloy Medical Implants

Abstract

The invention discloses an electron-beam melting and forming method of a magnesium-alloy medical implant. The electron-beam melting and forming method comprises the main steps of: (1) establishing a geometric model of the magnesium-alloy medical implant; (2) carrying out layering discrete on the geometric model; (3) generating a scanning path according to geometric profile information of the implant; (4) laying a magnesium-alloy powder material on a substrate of an electron-beam forming machine and compacting; (5) controlling the current amplitude of electron beams, carrying out selective melting on the powder according to the information of sections of all the layers, stacking in a layer-by-layer manner till forming; controlling process parameters in electron-beam melting and forming, wherein the vacuum degree of a forming chamber is 5*10-4Pa, a Z-shaped scanning mode is adopted, the accelerating voltage is 10-60kv, the current of electron beams is 1.0-4.0mA, the focusing current is 100-400mA, the line scanning speed is 50-150mm / s, and the distance between filling lines is 0.1-0.6mm. The electron-beam melting and forming method disclosed by the invention has the advantages that the whole forming process is simple in procedure and easy in control, the obtained implant is high in compactness and can be widely produced and applied in the medical field.

Description

technical field [0001] The invention belongs to the field of products produced by metal powder, and relates to an electron beam melting forming method of a magnesium alloy medical implant. Background technique [0002] Clinical medical implants are generally made of titanium alloys, stainless steel and other metals, but the metal ions released by these metals during corrosion or wear can easily lead to tissue defects and reduced biocompatibility. Moreover, these metals need to be removed by secondary operations, which increases the suffering of patients and medical costs. Magnesium alloy medical implants have good biocompatibility, and their Young's modulus (45GPa) is similar to that of human bone (20GPa), which can effectively alleviate the stress shielding effect. In particular, magnesium alloys can be gradually degraded and absorbed in the human body. Therefore, magnesium alloy medical implants have good application prospects in the field of biomedicine. [0003] Magne...

AI Technical Summary

Problems solved by technology

Compared with the selective laser melting forming method, this method has the advantages of high energy utilization rate, fast processing speed, no reflection and wide range of processed materials; however, due to the low density of magnesium alloy, the airflow of magnesium alloy powder at the moment of pumping in the vacuum chamber And high-speed, high-energy-density electron beam pressure is prone to collapse, causing the metal powder to deviate from the original position before forming and melting, and subsequent forming cannot be performed; in addition, the thermal conductivity of magnesium alloy is large, and the temperature gradient in different regions of the formed part is large, which is easy to cause Severe molding warpage

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