CN1978682A - High-strength high-elasticity modulus titanium alloy suitable for preparing foil material - Google Patents

Abstract

The invention relates to a high-strength and high-elastic-modulus titanium alloy suitable for preparing foil materials, which is an α+β two-phase titanium alloy, and when the whole is counted as 100% by weight, it contains titanium as the main component, 4.5 to 9.0 Aluminum in weight percent, boron in 0.2-1.5 percent by weight, β-stabilizing element in 0.5-5 percent by weight, characterized in that the β-phase accounts for 10-20 volume percent, and also contains 4-10 volume percent TiB phase, and the remaining for the alpha phase. The obtained titanium alloy foil has high strength, high elastic modulus and isotropic elastic modulus.

Description

A titanium alloy with high strength and high modulus of elasticity suitable for making foil

technical field

The invention relates to a titanium alloy, in particular to a high-strength and high-elastic-modulus titanium alloy suitable for preparing foil materials.

Background technique

When the elastic deformation of a metal material fully satisfies Hooke's law, the ratio of its stress to strain is the modulus of elasticity. The elastic modulus is essentially a physical parameter that characterizes the bonding strength between solid atoms. The smaller the atomic radius and ionic radius, the higher the atomic valence, the greater the elastic modulus. For selected materials, the elastic modulus is tissue insensitive.

Because titanium alloy has good specific strength and corrosion resistance, it has been widely used in fields such as aviation, military, space, deep sea exploration and chemical plants. The elastic modulus of titanium alloy is only about half of that of steel material, generally between 110 and 125GPa.

The elastic modulus of α-type titanium alloy is higher than that of β-type titanium alloy. The elastic modulus of commercial α-titanium alloy is about 120GPa, and the elastic modulus of commercial β-titanium alloy is about 110GPa. Except for pure titanium, the process plasticity of α-type titanium alloy is worse than that of β-type titanium alloy, and the deformation amount of a cold rolling cycle is only 8%.

The β-stabilizing elements did not significantly increase the elastic modulus of the β-phase. The commonly used α-phase stabilizing element, aluminum (Al), is the most commonly used α-phase stabilizing element in titanium alloys, and it can significantly increase the elastic modulus of the α-phase. In the range of not forming α ₂ phase (the weight percentage of aluminum is greater than 8%, an ordered phase (TiAl ₃ ), that is, α ₂ phase will be formed), for every 1% by weight of Al, the elastic modulus of α phase increases by 1.4GPa .

Although boron (B) is an α-phase stable element, its solubility in α-phase and β-phase is very small (less than 0.2 atomic %). It exists in the form of the second phase of TiB phase in titanium alloys. Its elasticity The modulus is as high as 355GPa, and its presence in titanium alloys can significantly improve the elastic modulus of titanium alloys. In pure titanium, when the volume fraction of TiB phase increases from 0% to 15%, the elastic modulus increases from 110GPa to 139GPa. In Ti-6Al-4V (weight percent) alloy (a multipurpose α+β alloy), when the volume fraction of TiB phase increases from 0% to 10%, the elastic modulus increases from 116GPa to 140GPa. The TiB phase exists in the form of the second phase particles in the titanium alloy, and it basically does not deform under the action of external stress, and the deformation coordination ability with the matrix is poor. The existence of the TiB phase significantly increases the elastic modulus of the titanium alloy, and at the same time deteriorates the processing performance and plasticity index of the titanium alloy.

Contents of the invention

The object of the present invention is to provide a titanium alloy suitable for preparing foils with high strength and high elastic modulus without deteriorating the processing performance and plastic index of the titanium alloy.

To achieve the above object, the present invention takes the following technical solutions:

A high-strength and high-elastic-modulus titanium alloy suitable for preparing foil materials, which is an α+β two-phase titanium alloy, and when the whole is counted as 100% by weight, it contains titanium as the main component, 4.5-9.0% by weight Aluminum, 0.2-1.5% by weight of boron, 0.5-5% by weight of β-stabilizing elements, characterized in that the titanium alloy contains 10-20% by volume of β-phase, 4-10% by volume of TiB phase, and the rest is α Mutually.

A preferred technical solution is characterized in that the β-stable element is a mixture of one or more of molybdenum, niobium, vanadium, chromium and iron in any proportion; when it is a mixture of multiple β-stable elements in any proportion , wherein the content of each β-stabilizing element is not less than 0.5% by weight.

A preferred technical solution is characterized in that the high-strength and high-elastic-modulus titanium alloy suitable for preparing foils also contains 0-3% by weight of neutral elements.

A preferred technical solution is characterized in that the neutral element is tin, zirconium, hafnium.

A preferred technical solution is characterized in that the high-strength and high-elastic-modulus titanium alloy suitable for preparing foils also contains interstitial elements of carbon, hydrogen, oxygen and nitrogen.

A preferred technical solution is characterized in that the oxygen content is 0.05-0.25% by weight.

The amount of other interstitial elements is controlled as conventional two-phase titanium alloys.

The high-strength and high-elastic-modulus titanium alloy suitable for preparing foil materials of the present invention can be smelted by vacuum autoconsumption, shell furnace smelting, plasma beam smelting, electron beam smelting, suspension furnace smelting, etc. A variety of smelting methods can be used for smelting, and a combination of these smelting methods can also be used for smelting. The pure metals include titanium, zirconium, aluminum, iron, chromium, vanadium, and hafnium; the intermediate alloys include aluminum-molybdenum alloys, aluminum-vanadium alloys, and titanium-boron alloys.

Beneficial effect

1) The titanium alloy of the present invention has a tensile strength Rm>1000MPa, a tensile elastic modulus E≥130GPa, and an elongation>7%.

2) The alloy of the present invention can have an appropriate amount of TiB phase with a high elastic modulus, which increases the elastic modulus of the alloy without significantly deteriorating the plastic index and processability of the alloy.

3) The alloy of the present invention has a sufficient volume percentage (70-80%) of α-phase that is strengthened by alloying elements and can also be texture-strengthened.

4) The alloy of the present invention has a certain volume (10-20% by volume) and is strengthened by alloying elements and has a β phase with a certain elastic modulus, which guarantees the technological plasticity of the alloy.

Detailed ways

Example 1

Sponge titanium, sponge zirconium, pure aluminum, pure hafnium, aluminum vanadium master alloy, aluminum molybdenum master alloy, aluminum niobium master alloy and titanium boron master alloy according to composition Ti-4.5Al-3Zr-0.5Hf-4Mo-1V-1Nb -1.2B-0.06O ingredients are used to press electrodes, which are smelted in a shell-condensing furnace and a vacuum consumable furnace, and smelted into ingots twice. The cast ingot is hot-blasted and slab-rolled to prepare a slab with a thickness of 1.2mm, and the slab is made into a 0.3mm foil by cyclic cold rolling and intermediate vacuum annealing. After the foil material is vacuum annealed at 1000°C/1h/FC, standard tensile specimens are prepared according to the national standard GB/T228-2000, and the mechanical properties are tested on Shimadzu AG50KNE universal material testing machine. The obtained tensile strength Rm, See Table 1 for elongation _A5 and tensile modulus E. Measured by quantitative metallographic method, the β phase in the microstructure accounts for 15% of the total volume; the TiB phase accounts for 6 volume%.

Example 2

Sponge titanium, sponge zirconium, pure aluminum, pure iron, pure chromium, aluminum-molybdenum master alloy, aluminum-niobium master alloy and titanium-boron master alloy respectively according to composition Ti-6Al-2Mo-2Cr-2Zr-0.5Fe-0.6B-0.22 The O ingredients are pressed into the electrode, and the ingot is smelted twice in a vacuum consumable furnace. The cast ingot is hot-blasted and slab-rolled to prepare a slab with a thickness of 1.2mm, and the slab is made into a 0.3mm foil by cyclic cold rolling and intermediate vacuum annealing. After the foil material is vacuum annealed at 1000°C/1h/FC, standard tensile specimens are prepared according to the national standard GB/T228-2000, and the mechanical properties are tested on Shimadzu AG50KNE universal material testing machine. The obtained tensile strength Rm, See Table 1 for elongation _A5 and tensile modulus E. Measured by quantitative metallographic method, the β phase in the microstructure accounts for 19% of the total volume; the TiB phase accounts for 4% by volume.

Example 3

Sponge titanium, pure aluminum, pure chromium, aluminum-vanadium master alloy, aluminum-molybdenum master alloy and titanium-boron master alloy are respectively pressed into electrodes according to the ingredients of Ti-8Al-2Mo-2V-1Cr-0.7B-0.12O, and plasma melting and Vacuum self-consumption smelting, twice smelting into ingots. The cast ingot is hot-blasted and slab-rolled to prepare a slab with a thickness of 1.2mm, and the slab is made into a 0.3mm foil by cyclic cold rolling and intermediate vacuum annealing. After the foil material is vacuum annealed at 1000°C/1h/FC, standard tensile specimens are prepared according to the national standard GB/T228-2000, and the mechanical properties are tested on Shimadzu AG50KNE universal material testing machine. The obtained tensile strength Rm, See Table 1 for elongation _A5 and tensile modulus E. Measured by quantitative metallographic method, the β phase in the microstructure accounts for 11% of the total volume; the TiB phase accounts for 5% by volume.

Example 4

Sponge titanium, sponge zirconium, pure aluminum, pure iron, pure chromium, titanium-tin master alloy, aluminum-molybdenum master alloy and titanium-boron master alloy respectively according to composition Ti-6Al-1Sn-2Zr-2Mo-2Cr-0.5Fe-0.3B -0.10O ingredients, melted in a suspension furnace, melted into ingots. The cast ingot is hot-blasted and slab-rolled to prepare a slab with a thickness of 1.2mm, and the slab is made into a 0.3mm foil by cyclic cold rolling and intermediate vacuum annealing. After the foil material is vacuum annealed at 1000°C/1h/FC, standard tensile specimens are prepared according to the national standard GB/T228-2000, and the mechanical properties are tested on Shimadzu AG50KNE universal material testing machine. The obtained tensile strength Rm, See Table 1 for elongation _A5 and tensile modulus E. Measured by quantitative metallographic method, the β phase in the microstructure accounts for 15% of the total volume; the TiB phase accounts for 3% by volume.

The tensile property of alloy in the embodiment of table 1

Alloy Rm(MPa) A ₅ (%) E(GPa) Ti-4.5Al-3Zr-0.5Hf-4Mo-1V-1Nb-1.2B-0.06O 1180 7.5 136 Ti-6Al-2Mo-2Cr-2Zr-0.5Fe-0.6B-0.22O 1150 9 138 Ti-8Al-2Mo-2V-1Cr-0.7B-0.12O 1180 7.5 136 Ti-6Al-1Sn-2Zr-2Mo-2Cr-0.5Fe-0.3B-0.10O 1050 10 132

From the above table, its tensile strength Rm>1000MPa, tensile elastic modulus E≥130GPa, elongation>7%.

Claims (6)

1, a kind of titanium alloy that is suitable for preparing the high-strength high-elasticity modulus of foil, it is the alpha+beta diphasic titanium alloy, in the time will all counting 100 weight %, contain the main ingredient titanium, the aluminium of 4.5～9.0 weight %, 0.2 the boron of～1.5 weight %, 0.5 the beta stable element of～5 weight % is characterized in that, described titanium alloy contains the β phase of 10～20 volume %, the TiB phase that also contains 4～10 volume %, surplus is the α phase.

2, the titanium alloy that is suitable for preparing the high-strength high-elasticity modulus of foil according to claim 1 is characterized in that, described beta stable element is one or more the mixing of arbitrary proportion in molybdenum, niobium, vanadium, chromium, the iron; When being the mixing of arbitrary proportion of multiple beta stable element, wherein the content of each beta stable element is not less than 0.5 weight %.

3, the titanium alloy that is suitable for preparing the high-strength high-elasticity modulus of foil according to claim 1 is characterized in that, also contains the neutral element of 0～3 weight % in the titanium alloy of the described high-strength high-elasticity modulus that is suitable for preparing foil.

4, the titanium alloy that is suitable for preparing the high-strength high-elasticity modulus of foil according to claim 1 is characterized in that described neutral element is tin, zirconium, hafnium.

5, the titanium alloy that is suitable for preparing the high-strength high-elasticity modulus of foil according to claim 1 is characterized in that, also contains interstitial element oxygen in the titanium alloy of the described high-strength high-elasticity modulus that is suitable for preparing foil.

6, the titanium alloy that is suitable for preparing the high-strength high-elasticity modulus of foil according to claim 5 is characterized in that the content of described oxygen is 0.05～0.25 weight %.