Selective laser melting forming device and method of medical magnesium alloy metal part

Abstract

The invention provides a selective laser melting forming device of a medical magnesium alloy metal part, which comprises a control device, a powder delivering and spreading device, a laser transmission mechanism, an air purification device and a closed forming chamber, wherein the powder delivering and spreading device comprises a hopper and powder spreading brushes arranged on two sides below the hopper, the upper part of the hopper is arranged in a way of corresponding to a feeding opening on the upper part of the forming chamber, and the lower parts of the powder spreading brushes horizontally correspond to the upper surface of a forming cylinder; the laser transmission mechanism is arranged outside and above the forming chamber and is arranged in a way of corresponding to the forming cylinder; the side wall of the forming chamber is provided with an air inlet and an air outlet, and the air purification device is connected with the air inlet and the air outlet respectively; and thecontrol device is connected with the powder delivering and spreading device, the laser transmission mechanism, the forming cylinder and the air purification device respectively. The invention also provides a selective laser melting forming method of the medical magnesium alloy metal part. The device and the method can manufacture parts which have complex shapes required in the medical field directly, and have the advantages of high forming efficiency and the like.

Description

technical field [0001] The invention belongs to the technical field of magnesium alloy parts manufacturing, and in particular relates to a selective laser melting forming device and method for medical magnesium alloy metal parts. Background technique [0002] At present, metal biomaterials commonly used clinically include stainless steel, titanium and titanium alloys, cobalt-chromium alloys, etc. Although these metal biomaterials are easy to manufacture, they have disadvantages: they may release toxic substances during corrosion or wear. metal ions or metal particles, leading to tissue defects and reduced biocompatibility. Furthermore, the modulus of elasticity of these metallic biomaterials is not quite commensurate with that of normal bone tissue, leading to a stress shielding effect that destabilizes the implant and necessitates a secondary surgery to remove it after the patient has fully healed. [0003] Magnesium is a special metal material with a density of 1.74g / cm3,...

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Problems solved by technology

[0002] At present, metal biomaterials commonly used clinically include stainless steel, titanium and titanium alloys, cobalt-chromium alloys, etc. Although these metal biomaterials are easy to manufacture, they have disadvantages: they may release toxic substances during corrosion or wear. metal ions or metal particles, leading to tissue defects and reduced biocompatibility

[0004] Although the application of magnesium and magnesium alloys in the medical field is of great significance, the manufacture of magnesium has the following defects: magnesium is highly chemically active, easily oxidized in the air, and can burn at high temperatures, so during the smelting process Complicated protection measures must be adopted, and flux protection method and gas protection method are mainly used in industry. At present, magnesium alloy parts are generally used in industry by die-casting production process. Although this production method can produce magnesium alloy parts, in the medical field, Since the required parts are generally used to obtain customized implants or surgical aids for individual patient information, that is, medical magnesium alloy parts need to be complex space-shaped parts that require a high degree of freedom. If the die-casting method is used it is difficult to meet the requirements

At present, selective laser melting technology has not been used to process and produce medical magnesium alloy parts.

[0006] Moreover, in the existing selective laser melting molding device, a double-cylinder structure composed of a powder cylinder and a molding cylinder is generally used. This structure has the following defects: (1) greatly increases the volume of the whole set of equipment (2) even if the molding is very Small parts also need to pour a lot of powder, resulting in a lot of waste; (3) The powder feeding device needs to run back and forth on the double cylinder, and the molding efficiency is low

Moreover, in the existing technology, there is generally no preheating device and structure, and warping and cracks during the molding process are often prone to occur. The complete melting of the powder requires relatively high input laser energy, which requires a large amount of energy consumption; at the same time For processing magnesium alloy parts, if there is no preheating device, the forming temperature and conditions of magnesium alloy powder cannot be met

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