CN104611611A - Preparation method for ultralow-elastic-modulus high-strength titanium alloy material - Google Patents

Abstract

The invention provides a method for preparing an ultra-low elastic modulus and high-strength titanium alloy material, which belongs to the technical field of biomedical material preparation. Using Ti, Mo, and Fe element powders as the main raw materials, the composition ratio is carried out according to the molybdenum equivalent of 6~38wt.%, the mixed powder is subjected to high-energy ball milling, and nanocrystalline titanium-based composite powder is obtained by adjusting the ball milling process parameters. Put the ball mill powder into the graphite mold and carry out spark plasma sintering. The sintering temperature is 800~1000℃. The advantage of this method is that the process is simple and the preparation period is short, and the prepared alloy is mainly composed of β-Ti and FCC-Ti two phases, and has the characteristics of ultra-fine grain structure. The prepared new titanium alloy has the characteristics of ultra-low elastic modulus, high strength and high plasticity. Its elastic modulus index matches that of natural bone and has excellent biomechanical adaptability.

Description

A kind of preparation method of ultra-low elastic modulus high-strength titanium alloy material

technical field

The invention provides a method for preparing an ultra-low elastic modulus and high-strength titanium alloy material, which belongs to the technical field of biomedical material preparation.

technical background

Titanium alloy has the advantages of good biocompatibility, high specific strength, low elastic modulus, corrosion resistance, etc., and has become the focus of development in the field of biomedical materials. At present, the clinically used titanium alloys are mainly Ti-6Al-4V and its improved alloys, but the elastic modulus of these alloys is about 80~110GPa, which is still larger than the elastic modulus of human tissue (10~30GPa), and it is difficult to compare with human bone. match. In addition, the precipitation of Al or V ions after long-term implantation in the body will also cause potential harm to the human body. On this basis, the design and development of new β-type titanium alloys that are non-toxic and have a lower elastic modulus have become the main development trend of medical titanium alloy materials.

At present, there are few domestic and foreign reports on ultra-low elastic modulus and high-strength β-titanium alloys. Among them, Yurie et al. designed and prepared a β-type Ti ₂₉ Nb ₁₃ Ta _4.6 Zr alloy with an elastic modulus of 60-67Gpa (Mechanical Strength and Bone Contactability of Biomedical Titanium Alloy with Low Young's Modulus Subjected to Fine Particle Bombarding Process. The Japan Institute of Metals and Materials, 2014, 78: 163-169); Li et al prepared ultra-fine-grained (Ti _69.7 Nb _23.7 Zr _4.9 Ta _1.7 ) ₉₄ Fe ₆ alloy by powder metallurgy method, and the study showed that the alloy was composed of β-Ti phase and FeTi phase Composition, the resulting elastic modulus is 52-54Gpa (Ultrafine -grained Ti-based composites with high strength and low modulus. Materials Science & Engineering A,2013,560: 857-861); Chrominski et al prepared β-type Ti-45Nb alloy with an elastic modulus of 57-68Gpa (Enhancement of mechanical properties of biocompatible Ti–45Nb alloy by hydrostatic extrusion. Journal of Materials Science, 2014,49: 6930-6936). The elastic modulus of the new β-titanium alloy reported so far is still far behind that of human tissue (10-30GPa). Therefore, the development of non-toxic, ultra-low elastic modulus and high-strength titanium alloy has important applications in the field of biomedical materials. prospect.

This patent proposes to greatly reduce the elastic modulus of the titanium alloy by preparing a β+FCC-Ti dual-phase titanium alloy, and improve its plastic index on the basis of maintaining the high strength of the titanium alloy. At present, there are no relevant research reports at home and abroad.

Contents of the invention

In order to solve the above problems, the object of the present invention is to provide a method for preparing an ultra-low elastic modulus high-strength titanium alloy material, which can be widely used in the field of biomedical materials.

The technical solution of the present invention is: a method for preparing an ultra-low elastic modulus high-strength titanium alloy material, the specific steps are as follows:

Step 1: Proportion of raw materials: Ti powder, Mo powder and Fe powder are the main raw materials. The mass percentage of various components is: Mo content 5~12%, Fe content 0~9%, and the composition meets Mo The equivalent range is 6~38wt%, and the calculation formula of Mo equivalent is: [Mo] equivalent=%Mo+%Fe/0.35+%Cr/0.63+%Mn/0.65+%Ni/0.8+%V/1.5+%W/2 +%Nb/3.6+%Ta/4.5, the balance is Ti and other trace alloying elements, spare;

Step 2: The mixed powder obtained in step 1 is subjected to high-energy ball milling, the ball milling process is carried out under the protection of an inert gas, the ball-to-material ratio is 5: 1 ~ 20: 1, the rotating speed is 600 ~ 1500r/min, and the ball milling time is 2 ~ 30h, to obtain Composite powder with uniform distribution of ingredients and grain size ≤ 150nm;

Step 3: Put the ball mill powder obtained in Step 2 into a graphite mold, then put it into a spark plasma sintering furnace, apply an axial pressure of 10~80MPa, and adopt a vacuum condition of a vacuum degree of 10 ^-2 ~6Pa or under the protection of an inert gas Carry out sintering, heat up at a speed of 50-300°C/min, raise the temperature to 800-1000°C, keep warm and cool to room temperature with the furnace, and then the titanium alloy bulk material composed of β+FCC-Ti two phases can be obtained. It is more than 97.0%.

The advantages of the present invention are:

(1) The new β+FCC-Ti dual-phase titanium alloy material has the characteristics of ultra-low elastic modulus, high strength and high plasticity. Its elastic modulus index matches that of natural bone and has excellent biomechanical adaptability. The density is above 97.0%, the elastic modulus is 15~32GPa, and the compressive strength is 2000~2800Mpa. (2) The prepared titanium alloy has an ultra-fine grain structure, which makes it have high osteoblast adhesion and performance For better biocompatibility.

(3) The process method is simple, the preparation cycle is short, numerical control operation can be realized, and the preparation process is highly repeatable.

Description of drawings

Fig. 1 is a scanning electron micrograph of the Ti-8Mo-3Fe alloy microstructure prepared in the present invention.

detailed description

The technical solutions of the present invention will be further described below in conjunction with specific embodiments.

Example 1

Ti, Mo and Fe element powders are used as raw materials, the particle size is -500 mesh, and the ratio is carried out according to the nominal composition Ti-8Mo-3Fe (molybdenum equivalent of 16.6wt.%). The mixed powder was subjected to vibratory high-energy ball milling. The ball milling process was carried out under the protection of high-purity argon, with a ball-to-material ratio of 10:1 and a rotational speed of 1000r/min. Composite powder with an average grain size of about 15nm was collected after ball milling for 10h. Put the ball mill powder into a Φ20 stone mill mold, then put the stone mill mold into a discharge plasma sintering furnace, vacuumize the system to 2Pa, add axial pressure to 40MPa, and heat up to 900°C at a speed of 100°C/min , after holding for 5 minutes and then cooling with the furnace, the Ti-8Mo-3Fe alloy bulk material is obtained. After testing, the prepared alloy sample is composed of β+FCC-Ti two phases, and its density is 98.95%, alloy. The mechanical properties of the sample are: the elastic modulus is 23.69GPa, the compressive strength is 2465MPa, and the compression breaking strain is 34.7%. The high-resolution field emission scanning electron microscope photos of the prepared samples are shown in Figure 1.

Example 2

Ti and Mo element powders are used as raw materials, the particle size is -325 mesh, and the ratio is made according to the nominal composition Ti-6Mo (molybdenum equivalent of 6 wt.%). The mixed powder is subjected to vibratory high-energy ball milling, and the ball milling process is carried out under the protection of high-purity argon, with a ball-to-material ratio of 10:1 and a rotational speed of 1200r/min. After ball milling for 8 hours, the composite powder with an average grain size of about 32nm was collected. Put the ball mill powder into a Φ20 stone mill mold, then put the stone mill mold into a spark plasma sintering furnace, vacuumize the system to 2Pa, add axial pressure to 40MPa, and heat up to 1000℃ at a speed of 100℃/min , after holding for 5 minutes and then cooling with the furnace, the Ti-6Mo alloy bulk material is obtained. After testing, the density of the prepared sample was 98.49%. The mechanical properties of the sample are: the elastic modulus is 19.44GPa, the compressive strength is 2248MPa, and the compression fracture strain is 31.3%.

Example 3

Ti, Mo and Fe element powders are used as raw materials, the particle size is -500 mesh, and the proportion is made according to the nominal composition Ti-8Mo-9Fe (molybdenum equivalent is 33.7 wt.%). The mixed powder was subjected to vibratory high-energy ball milling, and the ball milling process was carried out under the protection of high-purity argon, with a ball-to-material ratio of 15:1 and a rotational speed of 800r/min. After ball milling for 12 hours, the composite powder with an average grain size of about 9nm was collected. Put the ball mill powder into a Φ20 stone mill mold, then put the stone mill mold into a spark plasma sintering furnace, vacuumize the system to 2Pa, add axial pressure to 40MPa, and heat up to 850℃ at a speed of 100℃/min , After holding for 5 minutes and then cooling with the furnace, a Ti-8Mo-9Fe alloy bulk material is obtained. After testing, the prepared alloy sample is composed of β+FCC-Ti and a small amount of TiFe phase, and its density is 98.37%. The mechanical properties of the alloy sample are: the elastic modulus is 30.71GPa, the compressive strength is 2591MPa, and the compression fracture strain is 17.9 %.

Example 4:

Ti, Mo and Fe element powders are used as raw materials, the particle size is -500 mesh, and the proportion is carried out according to the nominal composition Ti-9Mo-6Fe-2Cr (molybdenum equivalent of 29.2wt.%). The mixed powder is subjected to vibratory high-energy ball milling, and the ball milling process is carried out under the protection of high-purity argon, with a ball-to-material ratio of 20:1 and a rotational speed of 600r/min. After ball milling for 25h, the composite powder with an average grain size of about 32nm was collected. Put the ball mill powder into a Φ20 stone mill mould, then put the stone mill mold into a spark plasma sintering furnace, vacuum the system to 6Pa, add an axial pressure of 80MPa, and heat up to 850°C at a speed of 300°C/min , heat preservation for 5 minutes and then cool down with the furnace to obtain Ti-9Mo-6Fe-2Cr alloy bulk material. After testing, the prepared alloy sample is composed of β+FCC-Ti, and its density is 97.7%. The mechanical properties of the alloy sample are: the elastic modulus is 29.6GPa, the compressive strength is 2223MPa, and the compression fracture strain is 27.9%.

Example 5:

Ti, Mo and Fe element powders are used as raw materials, the particle size is -500 mesh, and the proportion is carried out according to the nominal composition Ti-5Mo-7Fe (molybdenum equivalent of 25wt.%). The mixed powder was subjected to vibratory high-energy ball milling, and the ball milling process was carried out under the protection of high-purity argon, with a ball-to-material ratio of 15:1 and a rotational speed of 700r/min. Composite powder with an average grain size of about 95nm was collected after ball milling for 5h. Put the ball mill powder into a Φ20 stone mill mold, then put the stone mill mold into a discharge plasma sintering furnace, vacuumize the system to 5Pa, add axial pressure to 60MPa, and heat up to 900℃ at a speed of 250℃/min , after holding for 5 minutes and then cooling with the furnace, the Ti-5Mo-7Fe alloy bulk material is obtained. After testing, the prepared alloy sample is composed of β+FCC-Ti and a small amount of TiFe phase, and its density is 97.9%. The mechanical properties of the alloy sample are: the elastic modulus is 30.9GPa, the compressive strength is 2346MPa, and the compression fracture strain is 18.7 %.

Claims (2)

1. a preparation method for ultralow elasticity modulus high strength titanium alloy material, is characterized in that, the concrete steps of the method are as follows:

Step 1: proportioning raw material: with Ti powder, Mo powder and Fe powder for main raw material, counting according to mass percent of various composition: Mo content 5-12%, the content of Fe is 0-9%, composition meets Mo equivalent weight range is simultaneously 6-38wt%, Mo equivalent calculation formula is: [Mo] equivalent=%Mo+%Fe/0.35+%Cr/0.63+%Mn/0.65+%Ni/0.8+%V/1.5+%W/2+%Nb/3 .6+%Ta/ 4.5, surplus be Ti and and other trace alloying elements, for subsequent use;

Step 2: mixed powder step 1 obtained carries out high-energy ball milling, mechanical milling process carries out under protection of inert gas, and ratio of grinding media to material is 5:1 ~ 20:1, rotating speed 600 ~ 1500r/min, Ball-milling Time is 2 ~ 30h, obtains uniform composition distribution and the composite powder of grain-size≤150nm;

Step 3: ball-milled powder step 2 obtained loads in graphite jig, then inserts in discharge plasma sintering stove, applies the axle pressure of 10 ~ 80MPa, adopts vacuum tightness 10 ^-2sinter under the vacuum condition of ~ 6Pa or protection of inert gas, be that 50 ~ 300 DEG C/min heats up with speed, be warming up to 800 ~ 1000 DEG C, after insulation, cool to room temperature with the furnace, namely obtain titanium alloy block materials.

2. method according to claim 1, is characterized in that, described titanium alloy block materials is primarily of β+FCC-Ti two phase composite, and its density is more than 97.0%, and its Young's modulus is 15 ~ 32GPa, and compressive strength is 2000 ~ 2800Mpa.