Preparation method of Mg-Zn-Ca series biomedical magnesium alloy

Abstract

The invention relates to a preparation method of Mg-Zn-Ca series biomedical magnesium alloy, and belongs to the technical field of batch preparation of biomedical degradable magnesium alloy. The method comprises the steps of burdening, smelting and solidification system preparation, alloy smelting and purification, undercurrent transfer injection and forced filtration, precise solidification control and waste heat homogenization, near solidus homogenization treatment and plastic deformation treatment. The low-cost preparation technology has the greatest advantages that the preparation of a Mg-Zn-Ca series biomedical magnesium alloy ingot blank with the high thermal cracking tendency and the cross section area larger than 70000 mm <2> is met, homogeneous clean casting of industrial scale isachieved, and therefore the production efficiency can be greatly improved, the deformation degree is increased, and the performance is improved; and meanwhile, the cracking risk of a large cast ingotis greatly reduced, homogenization of a pasty area and a liquid phase area is achieved, the nucleation rate is increased, dendritic crystals are refined, and meanwhile specific gravity segregation and reverse segregation of Zn are effectively avoided.

Description

technical field [0001] The invention relates to a preparation method of Mg-Zn-Ca series biomedical magnesium alloy, in particular to a low-cost preparation method of Mg-Zn-Ca series biomedical deformed magnesium alloy, which belongs to the batch preparation technology of biomedical degradable magnesium alloy field. Background technique [0002] At present, the biomedical metal materials in clinical application mainly include stainless steel, titanium alloy, and cobalt-based alloy. These materials are all non-degradable materials. After a short-term implantation, they must be removed again, which increases the pain of patients and medical expenses. In addition, a common problem with existing metal implant materials such as stainless steel and titanium alloys is that they have poor mechanical compatibility with biological bone. The tensile strength of stainless steel and titanium alloys is more than five times higher than that of natural bone, and the elastic modulus is even h...

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Problems solved by technology

Thirdly, Ca with high melting point exists in the as-cast structure of Mg-Zn-Ca alloy 2 Mg 6 Zn 3 Ternary eutectic compound, the melting point is above 410°C, most of them are distributed in continuous or semi-continuous network between dendrites, in order to avoid oxidation and overburning, there are still a large number of compounds remaining after conventional homogenization process, after deformation There are coarse compound streamlines in the structure, which is very unfavorable to uniform corrosion. If the homogenization at a higher temperature can be carried out in a protective gas environment, the network compound becomes discrete spherical, which can increase the degree of deformation of the alloy blank. And these spherical compounds can hinder the growth of recrystallized grains

In short, the existing Mg-Zn-Ca biomedical magnesium alloy preparation technology is not suitable for industrial production with high cost requirements.

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