CN106148886A - Metallic titanium surface Fe powder urges the salt bath oozed ooze niobium agent and ooze niobium method - Google Patents

Abstract

A salt bath niobium infiltrating agent and niobium infiltrating method for catalytic infiltration of Fe powder on the surface of titanium metal, characterized in that the niobium infiltrating agent is composed of anhydrous borax (Na ₂ B ₄ O ₇ ), niobium oxide (Nb ₂ O ₅ ) , silicon carbide (SiC) and Fe powder, mix each component evenly and put it in an oven at 100℃～120℃, and dry it for 40min～60min to get the required salt bath niobium infiltrating agent for use. The niobium infiltrating method includes surface treatment of titanium alloy, heating of niobium infiltrating agent and insulated niobium in salt bath. The invention has the advantages of fast permeation speed, thick permeation layer, good workpiece surface quality, simple operation process and excellent economic performance, can be used in industrial production, and has broad application prospects in the fields of biomedicine and the like.

Description

Salt bath niobium infiltrating agent and niobium infiltrating method for catalytic infiltration of Fe powder on metal titanium surface

technical field

The invention relates to the field of chemical heat treatment, in particular to a niobium infiltrating agent and a niobium infiltrating process thereof, in particular to a salt bath niobium infiltrating agent and a niobium infiltrating process for infiltration of Fe powder on the surface of metal titanium.

Background technique

As biomedical materials, titanium and titanium alloys are widely used in hard tissue replacement, heart valves, vascular stents, tooth Roots and various orthopedic devices, etc. However, although its elastic modulus is lower than that of other biomedical materials, it is still much higher than that of human bone. However, its hardness is low, its coefficient of friction is large, its surface wear resistance is poor, and its corrosion resistance needs to be further improved. Because Ti-Nb alloy has the advantages of ultra-low elastic modulus, corrosion resistance and good biocompatibility, and the infiltration of niobium has been confirmed to enhance the hardness and wear resistance of pure titanium and titanium alloys, so niobium infiltration treatment is an important way to improve It is one of the effective means to reduce the wear resistance and corrosion resistance of titanium metal surface and reduce its elastic modulus.

At present, three surface technologies widely used in the preparation of niobium infiltration layer are: ion implantation technology, magnetron sputtering coating technology, and double-layer glow plasma infiltration metallization technology. Although these technologies have great advantages in terms of equipment technology and coating bonding performance, they generally have limitations such as high cost and poor flexibility, which largely limit their transformation to engineering practice. Moreover, the modified layer formed by the ion implantation technology is too thin, and the magnetron sputtering coating technology and the double-layer glow plasma metallization technology need to be completed under vacuum protection conditions, so the equipment is complicated and the operation is inconvenient.

Niobium infiltration technology in salt bath has the characteristics of high quality of infiltration layer, good performance, simple equipment, convenient operation and low cost. It is a promising surface strengthening technology. A large number of studies have shown that Fe powder is not only a good reducing agent, but also a good infiltration agent, which accelerates the infiltration rate, thereby increasing the thickness of the infiltration layer and improving the quality of the infiltration layer. As far as the applicant knows, no one has yet obtained a niobium layer on the surface of metal titanium by using the salt bath niobium infiltration technology catalyzed by Fe powder.

Contents of the invention

The purpose of the present invention is to solve the problems of high cost, poor flexibility, high equipment and environmental requirements in the existing niobium infiltration technology on the surface of titanium alloys, and to invent a salt bath niobium infiltration agent and its infiltration agent for the infiltration of Fe powder on the surface of metal titanium. Niobium method, which can not only obtain niobium infiltrated layer with excellent surface quality while increasing the infiltration rate, but also has good operability and excellent economy.

One of technical solutions of the present invention is:

A salt bath niobium infiltrating agent for catalyzed infiltration by Fe powder on the surface of titanium metal is characterized in that it consists of anhydrous borax (Na ₂ B ₄ O ₇ ), niobium oxide (Nb ₂ O ₅ ), silicon carbide (SiC) and Fe powder Composition, wherein the mass percentage of Na ₂ B ₄ O ₇ is 78% to 88%; the mass percentage of Nb ₂ O ₅ is 8% to 12%; the mass percentage of SiC is 2% to 6%; the mass percentage of Fe powder is 2% to 4%, the mass percentage of each component is 100%, the silicon carbide is green and pure, the particle size is 150-200 mesh, and the purity of niobium oxide is 99.5%; mix the various components in the mass percentage evenly Afterwards, place it in an oven at 100°C to 120°C, and dry it for 40min to 60min to obtain the required salt bath niobium infiltrating agent for use.

The second technical scheme of the present invention is:

A kind of niobium penetration method of the salt bath niobium penetration agent that Fe powder catalyzes penetration on the surface of metal titanium is characterized in that it comprises the following steps:

(1) Surface pretreatment of titanium metal: After the surface of titanium metal is degreased and cleaned with deionized water, the surface is sanded and mechanically polished, and the surface is polished to a roughness of no more than Ra0.5μm, and then ultrasonically cleaned with acetone for at least 20 minutes;

(2) Niobium infiltrating treatment: put the crucible with niobium infiltrating agent into a resistance furnace, heat it to 850°C to melt all the borax; Mix well with a metal rod for half an hour;

(3) Put the workpiece into the prepared niobium infiltration salt bath, and keep the main working surface of the workpiece perpendicular to the flow direction of the salt bath as far as possible, keep it warm for 4-10 hours and take it out for air cooling, that is, a niobium infiltration layer is prepared on the surface of metal titanium.

(4) Clean the workpiece: put the workpiece into boiling water and boil until the bonded borax is removed.

The sanding refers to sanding with 120 ^# , 280 ^# , 400 ^# , 800 ^# , 1000 ^# respectively.

The beneficial effects of the present invention are:

(1) The present invention provides a salt bath niobium infiltrating agent and its niobium infiltrating process, which are simple in operation, low in cost, and excellent in process performance, and are infiltrated by Fe powder on the surface of metal titanium.

(2) The present invention does not need vacuum protection, and the metal titanium can be infiltrated with niobium under air conditions.

(3) The present invention increases the niobium infiltrating rate, increases the thickness of the infiltrating layer, produces a high hardness and high toughness niobium infiltrating layer, has obvious and gradient element diffusion between the substrate and the matrix, and has a good interface bond.

(4) Under the same niobium infiltrating process parameters, compared with the niobium infiltrating layer without Fe powder, the thickness of the niobium infiltrating layer with Fe powder is greatly increased, with an increase of 837%; the hardness of the outer layer is slightly improved, with an increase of 8.3% %.

(5) The present invention is not only applicable to various types of titanium alloys, but also applicable to the surface treatment of pure titanium materials.

The niobium infiltrating agent of the present invention has added 2% to 4% Fe powder as an infiltrating agent, and the preparation method and the niobium infiltrating process of the niobium infiltrating agent have been determined at the same time. The soaking time of niobium infiltration is 4h～10h. Through the above niobium infiltrating agent and niobium infiltrating process, the thickness of the niobium infiltrating layer successfully prepared on the surface of titanium metal is 15 μm, which is 837% higher than that of the niobium infiltrating layer without adding Fe powder; the niobium infiltrating layer is closely combined with the substrate, There are no cracks and holes; the content of Nb is up to 33% (At%); there is obvious and gradient element diffusion with the matrix, and the interface is well bonded; the microhardness of the outer layer of the niobium infiltrated layer is 1021.8HV, compared with that without adding Fe powder infiltrated niobium layer is slightly improved, about 8.3%.

The invention has fast penetration rate, thick penetration layer, good workpiece surface quality, simple operation process and excellent economic performance, can be used in industrial production, and has broad application prospects in the fields of biomedicine and the like.

Description of drawings

Fig. 1 is a scanning electron microscope image of the niobium infiltrated layer of the titanium alloy in Example 1 after being kept at 950° C. for 4 hours.

Fig. 2 is a scanning electron microscope image of the niobium infiltrated layer of the titanium alloy in Example 2 after being kept at 950° C. for 4 hours.

Fig. 3 is an element diffusion diagram of the niobium infiltrated layer of the titanium alloy in Example 1 after being kept at 950° C. for 4 hours.

Fig. 4 is a comparative diagram of the hardness distribution of the niobium-infiltrated layer on the titanium alloy surface in Example 1 and Example 2.

detailed description:

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

Example 1.

A method for infiltrating niobium on the surface of metal titanium, which comprises the preparation of salt bath infiltrating niobium agent-pretreatment on the surface of metal titanium-niobium infiltrating treatment-cleaning workpiece.

(1) Preparation of niobium infiltration agent in salt bath, take 840 grams of anhydrous borax (Na ₂ B ₄ O ₇ ), 100 grams of niobium oxide (Nb ₂ O ₅ ) (purity 99.5%), green and pure, with a particle size of 150~ 40 grams of 200-mesh silicon carbide (SiC) and 20 grams of Fe powder (purity 99.99%), mixed evenly, placed in an oven at 120 ° C, dried for 40 minutes to obtain the required salt bath niobium infiltrating agent for use.

(2) Wire-cut TC4 titanium alloy rods into 10mm×12mm×3mm profiles for later use; degreasing and cleaning the titanium surface with deionized water, then sanding the surface with sandpaper (choose 120 ^# , 280 ^# , 400 ^# in sequence , 800 ^# , 1000 ^# ) and mechanical polishing, the surface is polished to a roughness of Ra0.5μm, and then ultrasonically cleaned with acetone for 20 minutes;

(3) Niobium infiltrating treatment: Put the crucible with niobium infiltrating agent into the resistance furnace, heat it to 850°C to melt all the borax; Stir with a metal rod;

(4) Put the titanium alloy workpiece after ultrasonic cleaning into the niobium infiltration salt bath prepared in the previous step, and keep the main working surface of the workpiece perpendicular to the flow direction of the salt bath as much as possible. A niobium infiltrated layer is obtained.

(3) Clean the workpiece: put the workpiece into boiling water and cook until the bonded borax is removed.

After the sample is taken out, it is tested. The thickness of the niobium infiltrated layer with Fe powder added is 15 μm as detected by scanning electron microscope (Figure 1), which is 837% higher than that of the niobium infiltrated layer without Fe powder added; ; Nb content up to 33% (At%); there is obvious and gradient element diffusion between the substrate and the matrix (Figure 3), and the interface is well bonded; the microhardness of the outer layer of the niobium infiltrated layer is 1021.8HV, compared with that without Fe powder The niobium penetration layer is slightly improved, about 8.3% (Figure 4).

The following are comparative examples:

Example 2.

The method is basically the same as in Example 1, except that the niobium infiltrating agent used does not add Fe powder catalyst, and the mass percentage of SiC is 6%.

Test after taking out the sample. The thickness of the infiltrated layer is 1.6 μm (Fig. 2), and the microhardness of the outer layer of the niobium infiltrated layer is 943.4HV through metallographic microscope inspection.

Embodiment three.

A method for infiltrating niobium on the surface of metal titanium, which comprises the preparation of salt bath infiltrating niobium agent-pretreatment on the surface of metal titanium-niobium infiltrating treatment-cleaning workpiece.

(1) Preparation of niobium infiltration agent in salt bath, take 780 grams of anhydrous borax (Na ₂ B ₄ O ₇ ), 120 grams of niobium oxide (Nb ₂ O ₅ ) (purity 99.5%), green and pure, with a particle size of 150~ 40 grams of 200-mesh silicon carbide (SiC) and 60 grams of Fe powder (purity 99.99%), mixed evenly, placed in an oven at 100 ° C, and dried for 60 minutes to obtain the required salt bath niobium infiltrating agent for use.

(2) Wire-cut TC4 titanium alloy rods into 10mm×12mm×3mm profiles for later use; degreasing and cleaning the titanium surface with deionized water, then sanding the surface with sandpaper (choose 120 ^# , 280 ^# , 400 ^# in sequence , 800 ^# , 1000 ^# ) and mechanical polishing, the surface is polished to a roughness of Ra0.5μm, and then ultrasonically cleaned with acetone for 25 minutes;

(3) Niobium infiltrating treatment: Put the crucible with niobium infiltrating agent into a resistance furnace, heat it to 850°C to melt all the borax; Mix well with a metal rod for half an hour;

(4) Put the titanium alloy workpiece after ultrasonic cleaning into the niobium infiltration salt bath prepared in the previous step, and keep the main working surface of the workpiece perpendicular to the flow direction of the salt bath as far as possible, keep it warm for 6 hours and take it out for air cooling, that is, on the surface of the titanium metal A niobium infiltrated layer is obtained.

(3) Clean the workpiece: put the workpiece into boiling water and cook until the bonded borax is removed.

After the sample is taken out, it is tested. The thickness of the niobium infiltrated layer with Fe powder was detected by scanning electron microscope to be 14.5 μm, which was 800% higher than that of the niobium infiltrated layer without Fe powder added; up to 32% (At%); there is obvious and gradient element diffusion between the substrate and the matrix (similar to Figure 3), and the interface is well bonded; the microhardness of the outer layer of the niobium infiltrated layer is 1022.7HV, compared with that without adding Fe powder The niobium infiltration layer is slightly improved, about 8.2% (similar to Figure 4).

Embodiment four.

A method for infiltrating niobium on the surface of metal titanium, which comprises the preparation of salt bath infiltrating niobium agent-pretreatment on the surface of metal titanium-niobium infiltrating treatment-cleaning workpiece.

(1) Preparation of niobium infiltration agent in salt bath, take 880 grams of anhydrous borax (Na ₂ B ₄ O ₇ ), 80 grams of niobium oxide (Nb ₂ O ₅ ) (purity 99.5%), green and pure, with a particle size of 150~ Mix 20 grams of 200-mesh silicon carbide (SiC) and 20 grams of Fe powder (purity 99.99%), place in an oven at 110°C, and dry for 50 minutes to obtain the required salt-bath niobium infiltrating agent for use.

(2) Wire-cut TC4 titanium alloy rods into 10mm×12mm×3mm profiles for later use; degreasing and cleaning the titanium surface with deionized water, then sanding the surface with sandpaper (choose 120 ^# , 280 ^# , 400 ^# in sequence , 800 ^# , 1000 ^# ) and mechanical polishing, the surface is polished to a roughness of Ra0.5μm, and then ultrasonically cleaned with acetone for 20 minutes;

(3) Niobium infiltrating treatment: put the crucible with niobium infiltrating agent into a resistance furnace, heat it to 850°C to melt all the borax; Mix well with a metal rod for half an hour;

(4) Put the titanium alloy workpiece after ultrasonic cleaning into the niobium infiltration salt bath prepared in the previous step, and keep the main working surface of the workpiece perpendicular to the flow direction of the salt bath as much as possible. A niobium infiltrated layer is obtained.

(3) Clean the workpiece: put the workpiece into boiling water and cook until the bonded borax is removed.

After the sample is taken out, it is tested. The thickness of the niobium layer added with Fe powder was detected by scanning electron microscope to be 15.1 μm, an increase of 800% compared with the thickness of the niobium layer without Fe powder; the niobium layer was tightly bonded to the substrate without cracks and holes; up to 33.2% (At%); there is an obvious and gradient element diffusion between the substrate and the matrix (similar to Figure 3), and the interface is well bonded; the microhardness of the outer layer of the niobium infiltrated layer is 1023.7HV, compared with that without adding Fe powder The niobium infiltration layer is slightly improved, about 8.2% (similar to Figure 4).

Embodiment five.

A method for infiltrating niobium on the surface of metal titanium, which comprises the preparation of salt bath infiltrating niobium agent-pretreatment on the surface of metal titanium-niobium infiltrating treatment-cleaning workpiece.

(1) Preparation of niobium infiltration agent in salt bath, take 800 grams of anhydrous borax (Na ₂ B ₄ O ₇ ), 100 grams of niobium oxide (Nb ₂ O ₅ ) (purity 99.5%), green and pure, with a particle size of 150~ 60 grams of 200-mesh silicon carbide (SiC) and 40 grams of Fe powder (purity 99.99%), mixed evenly, placed in an oven at 105 ° C, dried for 45 minutes to obtain the required salt bath niobium infiltrating agent for use.

(2) Wire-cut TC4 titanium alloy rods into 10mm×12mm×3mm profiles for later use; degreasing and cleaning the titanium surface with deionized water, then sanding the surface with sandpaper (choose 120 ^# , 280 ^# , 400 ^# in sequence , 800 ^# , 1000 ^# ) and mechanical polishing, the surface is polished to a roughness of Ra0.5μm, and then ultrasonically cleaned with acetone for 20 minutes;

(3) Niobium infiltrating treatment: put the crucible with niobium infiltrating agent into a resistance furnace, heat it to 850°C to melt all the borax; Mix well with a metal rod for half an hour;

(4) Put the titanium alloy workpiece after ultrasonic cleaning into the niobium infiltration salt bath prepared in the previous step, and keep the main working surface of the workpiece perpendicular to the flow direction of the salt bath as much as possible. A niobium infiltrated layer is obtained.

(3) Clean the workpiece: put the workpiece into boiling water and cook until the bonded borax is removed.

After the sample is taken out, it is tested. The thickness of the niobium infiltrated layer with Fe powder added is 15.2 μm by scanning electron microscope, which is 800% higher than that of the niobium infiltrated layer without Fe powder added; up to 34% (At%); there is an obvious and gradient element diffusion between the substrate and the matrix (similar to Figure 3), and the interface is well bonded; the microhardness of the outer layer of the niobium infiltrated layer is 1025.4HV, compared with that without adding Fe powder The niobium infiltration layer is slightly improved, about 8.2% (similar to Figure 4).

The parts not involved in the present invention are the same as the prior art or can be realized by adopting the prior art.

Claims (3)

1. A salt bath niobium infiltrating agent for Fe powder catalyzed infiltration on the surface of titanium metal is characterized in that it consists of anhydrous borax (Na ₂ B ₄ O ₇ ), niobium oxide (Nb ₂ O ₅ ), silicon carbide (SiC) and The composition of Fe powder, in which the mass percentage of Na ₂ B ₄ O ₇ is 78% to 88%; the mass percentage of Nb ₂ O ₅ is 8% to 12%; the mass percentage of SiC is 2% to 6%; the mass percentage of Fe powder The percentage is 2% to 4%, the mass percentage of each component is 100%, the silicon carbide is green and pure, the particle size is 150 to 200 mesh, and the purity of niobium oxide is 99.5%; the various components of the mass percentage, After mixing evenly, place it in an oven at 100°C to 120°C, and dry it for 40 minutes to 60 minutes to obtain the required salt bath niobium infiltrating agent for use. 2. a kind of niobium penetration method of the salt bath niobium penetration agent of the metal titanium surface Fe powder catalysis osmosis described in claim 1 is characterized in that it comprises the following steps: (1) Surface pretreatment of titanium metal: After the surface of titanium metal is degreased and cleaned with deionized water, the surface is sanded and mechanically polished, and the surface is polished to a roughness of no more than Ra0.5μm, and then ultrasonically cleaned with acetone for at least 20 minutes; (2) Niobium infiltrating treatment: put the crucible with niobium infiltrating agent into a resistance furnace, heat it to 850°C to melt all the borax; Mix well with a metal rod for half an hour; (3) Put the workpiece into the prepared niobium infiltration salt bath, and keep the main working surface of the workpiece perpendicular to the flow direction of the salt bath as much as possible, keep it warm for 4-10 hours and take it out for air cooling, that is, a niobium infiltration layer is prepared on the surface of metal titanium; (4) Clean the workpiece: put the workpiece into boiling water and boil until the bonded borax is removed. 3. The method according to claim 2, characterized in that said sandpaper grinding refers to grinding with 120 ^# , 280 ^# , 400 ^# , 800 ^# , 1000 ^# respectively.