CN-118080782-B - Investment casting mould shell preparation method suitable for zirconium-niobium alloy artificial joint prosthesis

CN118080782BCN 118080782 BCN118080782 BCN 118080782BCN-118080782-B

Abstract

A method for preparing investment casting mould shell suitable for artificial joint prosthesis of zirconium niobium alloy, it is the preparation field of investment casting mould shell, assemble the wax mould of joint to form a module, then wash the wax mould clean with the cleaning solution, blow the excessive area of cleaning solution with the high-pressure air gun before casting the surface layer slurry, then dip in surface layer slurry, facing layer slurry, backing layer slurry and slurry-sealing layer slurry that is prepared in turn and scribble and hang the slurry, hang sand, dry and harden after each time of offering, dewax, get the new zirconium niobium alloy joint type shell through the high-temperature roasting. The invention breaks through the limitation that zirconium-niobium alloy joints are usually only forged, and obtains the shell capable of bearing the high melting point of zirconium-niobium alloy through researches on the proportion of the binder, the dosage and the like, the surface layer of the shell does not react with the surface of the zirconium-niobium alloy, the characteristics of medical implants with high surface requirements are met, a good foundation is laid for smelting and casting of artificial joint prosthesis shells, and the trend of the artificial joint is promoted to be high-end.

Inventors

LI JIAWEI
Ling Lishibao
HU ZHI

Assignees

江西磊熠生物新材料有限公司

Dates

Publication Date: 20260512
Application Date: 20240426

Claims (3)

1. The method for preparing the investment casting mould shell of the zirconium-niobium alloy artificial joint prosthesis is characterized by comprising the following steps of: (1) Cleaning the wax mould, namely cleaning the assembled wax mould module with butanone for one time and then with penetrating agent, blowing air into the area with excessive solution by using a high-pressure air gun before preparing the surface layer slurry, avoiding the area from generating effusion, and standing and drying the cleaned module for 24 hours; (2) The preparation method comprises the steps of preparing three solutions, adding 0.5-2wt.% high-purity boric acid into the three solutions, mixing the binders according to the weight ratio, stirring every 3 hours to enable powder to be completely dissolved in the solution, enabling the binders to be in a transparent state, suspending the powder on the surface of the liquid, standing for 24 hours in a closed and dry environment, mixing the mixed binders for 24 hours with yttrium oxide powder with 300-400 meshes, enabling the solid-to-liquid ratio of the slurry to be 2.0-3.0:1, adding 2ml/30kg of a fast penetrating agent and 2ml/30kg of an antifoaming agent, carrying out rotary stirring, and then carrying out vacuumizing treatment, wherein the obtained slurry viscosity of the surface layer is 21-23 seconds, the effective life time is 30-60 minutes, and then spraying yttrium oxide sand with 60-80 meshes on the surface layer after the slurry is coated with a wax mold, and then drying the surface layer under the conditions of 23+/-3 ℃ and 70 ℃ humidity of 70+/-5 hours to obtain a shell of the surface layer; (3) Mixing the adhesive with 300-400 mesh yttrium oxide powder, mixing the adhesive with the slurry solid-liquid ratio of 0.8-2.0:1, adding defoaming agent n-octanol 2ml/30kg, carrying out rotary stirring at a high speed and a low speed, obtaining slurry viscosity of 8-10 seconds, refrigerating for 12 hours, spraying sand for 40-70 mesh yttrium oxide sand on the surface layer after the slurry is coated on a module, and then drying for 24 hours under the conditions of 23+/-3 ℃ and 60+/-5 humidity; (4) The adhesive of the backing layer 1 and the backing layer 2 is mixed according to the mass ratio of alcohol to ethyl silicate to hydrochloric acid of 5.0-6.0L to 100ml, and the adhesive is stood for 48 hours in a closed and dry environment after being mixed according to the mass ratio; the solid-to-liquid ratio of the sizing agent of the backing layer 1 and the backing layer 2 is 0.5-1.5:0.5-1.5; the back layer 1 and back layer 2 slurry is prepared by mixing ethyl silicate mixed binder which is kept stand for 48h with bauxite powder of 200-300 meshes, stirring for 1h at a stirring speed of 100r/min, the back layer 1 and back layer 2 slurry viscosity is 3-5 seconds, back layer 3 and later back layers use silica sol as binder, the solid-to-liquid ratio of the slurry is 1.5-2.5:1, the prepared silica sol is mixed with bauxite powder of 200-300 meshes, stirring for 1h at a stirring speed of 100r/min, the back layer slurry viscosity is 5-10 seconds, the whole module is immersed in the back layer 1 slurry for coating, the whole module is dried for 12h under the environment of 40-70 meshes of bauxite sand, the temperature is 23+/-3 ℃ and the humidity is 60+/-5, then immersing the module in the back layer 2 slurry for coating, the whole module is extracted from the back layer 2 slurry, the prepared silica sol is subjected to the spraying operation with 30-60 meshes of bauxite sand, the temperature is 23+/-3 ℃ and the humidity is 60+/-5 ℃ and the back layer is dried for 3 h, the whole module is immersed in the back layer 1 slurry for 3 h under the environment of 30-60 ℃ and the humidity is then immersed in the back layer 2 sand for 3 h, the whole module is dried for 3 h under the environment of 3 ℃ and the temperature is extracted from the back layer 1 to the back layer 3 h, the back layer is dried for 3 h, the whole module is sequentially immersed for 3 h under the temperature of 3 ℃ and the back layer is dried for 3 h under the temperature of 3 ℃ and 3 h, and the back layer is 3 h after the back layer is 3 and the temperature is 3 is dried, drying for 12 hours in the environment with humidity of 60+/-5 to obtain the final back layer shell; (5) Sealing slurry, namely mixing silica sol with 200-300 meshes of bauxite powder according to the solid-to-liquid ratio of slurry of 1.5-2.5:1, stirring for 1 hour at the stirring speed of 100r/min for 5-10 seconds to obtain slurry of a slurry sealing layer, immersing the back layer shell obtained in the step (4) into the slurry of the slurry sealing layer for hanging coating, and drying and hardening for 24 hours after the coating is carried out to prepare the shell slurry sealing layer; (6) And (3) roasting, namely firstly dewaxing the slurry-sealed shell prepared in the step (5) at 300-400 ℃ for 30 minutes, storing for 2-6 hours after dewaxing, putting into a box-type electric roasting furnace, and roasting for 2-6 hours at 1050+/-10 ℃ to obtain the shell of the zirconium-niobium alloy artificial joint prosthesis.
2. The method for preparing the investment casting mould shell of the zirconium niobium alloy artificial joint prosthesis, which is disclosed in claim 1, is characterized in that the parameters of the adhesive silica sol are that SiO 2 is 20-30% by mass, the specific gravity is 1.32g/cm 3 , the pH value is 9.7-10.5, and the colloid particle size is 8-12nm.
3. The method of preparing an investment casting mold shell for a zirconium niobium alloy prosthetic joint as claimed in claim 1, wherein the operation of step (4) is repeated 6 to 8 times of the operations of coating, sanding and dry hardening in the back layer slurry.

Description

Investment casting mould shell preparation method suitable for zirconium-niobium alloy artificial joint prosthesis Technical Field The invention belongs to the technical field of investment casting shells, and particularly relates to a preparation method of an investment casting mould shell of a zirconium-niobium alloy artificial joint prosthesis. Background The zirconium-niobium alloy is an ideal material for preparing high-end artificial joint prostheses, and the joint prostheses prepared by the material can effectively relieve pain and improve knee joint movement, reduce prosthetic loosening and peripheral bone resorption, and has good clinical and imaging evaluation verification effects, so that the zirconium-niobium alloy is increasingly applied to clinic. At present, only the orthopaedics megahead schlegend company adopts forging and machining processes to produce the zirconium-niobium joint product, and compared with the traditional investment precision casting process of cobalt-chromium-molybdenum alloy joints, the forging and machining processes of the zirconium-niobium joint product are very complex, are difficult to produce in a large scale, and have high cost, so that the imported price is high. The invention aims to provide a zirconium-niobium alloy joint investment casting process scheme, wherein the preparation of a ceramic shell is a key process of investment casting, the investment casting requires that the shell has enough normal-temperature and high-temperature strength, is stable in thermochemical mode, low in thermal expansion coefficient, high in air permeability and low in residual strength and has certain surface strength, and is generally composed of a high-inertia compact surface layer and a high-temperature-resistant breathable back layer. In order to inhibit the physicochemical reaction between the molten metal and the shell, the surface layer shell prepared from the surface layer refractory material and the binder must have low roughness and be chemically inert to the molten metal at high temperature. As the zirconium-niobium alloy has high chemical activity in a molten state, the casting temperature is over 2000 ℃, the surface of a shell prepared from the conventional zirconium powder (sand) surface ceramic refractory material is not compact enough and is easy to react with metal to form a reaction layer, and the zirconium-niobium alloy cannot be precisely molded, so that the shell preparation of the investment casting zirconium-niobium alloy artificial joint prosthesis is a difficult problem in an investment casting process scheme. However, at present, no mold shell preparation process scheme suitable for zirconium-niobium alloy joint investment casting is reported. Therefore, the invention designs the formula of the shell surface layer and the back layer material according to the characteristics and the casting process conditions of the zirconium-niobium alloy, optimizes the technological parameters of dipping slurry, sand spraying, dewaxing and roasting of the shell, develops a novel 2000 ℃ ultrahigh temperature resistant and high inert ceramic surface layer system, inhibits the reaction of the shell surface layer and the molten metal, forms an interface reaction inhibition technology between the zirconium-niobium superalloy melt and the surface layer, and improves the surface quality of castings. Disclosure of Invention The invention aims to provide a novel preparation method of an investment casting mould shell of a zirconium-niobium alloy artificial joint prosthesis. The shuttering formula comprises a surface layer, a yttrium oxide sand layer, a multi-layer and a bauxite powder, wherein the surface layer slurry formula comprises 66-75wt% of yttrium oxide powder, 3.5-7wt% of zirconium acetate, 14.7-24wt% of ammonium metatungstate, 1.7-5.2wt% of deionized water and 0.5-2wt% of high-purity boric acid, the yttrium oxide powder is 300-400 mesh powder particles, the back layer slurry formula comprises a binder prepared from ethyl silicate, alcohol and hydrochloric acid and the bauxite powder, the bauxite powder is 200-300 mesh powder particles, and the bauxite powder is scattered after the back layer slurry. The invention relates to a method for preparing an investment casting mould shell of a zirconium-niobium alloy artificial joint prosthesis, which comprises the following steps of. And (2) cleaning the wax mould, namely cleaning the assembled wax mould module with butanone for one time and then with penetrating agent, blowing air into the area with excessive solution by using a high-pressure air gun before preparing the surface layer slurry, avoiding the area from generating effusion, and standing and drying the cleaned module for 24 hours. The surface layer is prepared by mixing the surface layer binder with deionized water, zirconium acetate and ammonium metatungstate (0.5-1.5:1.0-2.0:4.0-5.0), adding high-purity boric acid with the total mass of 0.5-2 wt%, stirring every