CN106011537A

CN106011537A - Fine grain high-strength and high-toughness beta titanium alloy and manufacturing method thereof

Info

Publication number: CN106011537A
Application number: CN201610395716.5A
Authority: CN
Inventors: 张长江; 张树志; 吕智丹; 张佳欣; 王怡; 陈瑞梅
Original assignee: Taiyuan University of Technology
Current assignee: Taiyuan University of Technology
Priority date: 2016-06-07
Filing date: 2016-06-07
Publication date: 2016-10-12
Anticipated expiration: 2036-06-07
Also published as: CN106011537B

Abstract

The invention relates to the field of titanium alloys, in particular to a fine grain high-strength and high-toughness beta titanium alloy and a manufacturing method thereof. The fine grain high-strength and high-toughness beta titanium alloy comprises the following elements in percentage by mass: 3.0-7.0% of Al, 4-9% of Mo, 7-9% of V, 2-5% of Cr, 0.5-1% of Sn, 1-3% of Zr, and the balance of Ti and inevitable impurity elements; and grains of the titanium alloy are less than 3 microns. The invention further discloses the manufacturing method of the titanium alloy. The fine grain high-strength and high-toughness beta titanium alloy is an alloy with close grains, mixed with vein stripes and with high strength, high plasticity, high toughness and high comprehensive performance.

Description

A kind of thin brilliant high tough beta-titanium alloy and preparation method thereof

Technical field

The present invention relates to titanium alloy field, specifically a kind of thin brilliant high tough beta-titanium alloy and preparation method thereof.

Background technology

Along with a new generation's advanced weaponry is towards the great-leap-forward development in the directions such as high speed, maximization, structure complication, it is desirable to Titanium alloy structure material has high specific strength, high specific stiffness, high tenacity, high damage tolerance and solderable etc. excellent comprehensive Can coupling.Additionally, the securing members such as each load-carrying member of the weaponrys such as Aero-Space, weapons, boats and ships, load bolt are all to high-strength titanium Alloy and superhigh intensity titanium alloy propose clear and definite demand.Therefore, superhigh intensity titanium alloy (Rm >=1250MPa) becomes new one One of critical support material for Weapon Development, is one of the important directions of titanium alloy development and application research, in the world The research and development of advanced country is the most active.Wherein represent international most advanced level and obtain the main of reality application aboard There are Ti-10-2-3, BT22, Ti-15-3, β-21S, VST55531 etc..These alloys are mainly used to prepare rising and falling of aircraft Frame, pipeline, spring, engine support, cargo door, cabin, empennage and engine nozzle etc..For domestic, although high-strength The research of titanium alloy is also compared early with application aspect, and has developed the high-strength beta-titanium alloy of many trades mark, but domestic high-strength Beta-titanium alloy mostly is to be copied external alloy.The subject matter that current high-strength titanium alloy research and development face is its intensity-mould Property-matching of toughness is relatively low, i.e. plasticity under high intensity level is the lowest with toughness and cause it can not be at this intensity level Lower use, this severely limits development and the application of high-strength titanium alloy.

Summary of the invention

The technical problem to be solved is: how to provide the titanium conjunction that the matching of a kind of intensity-plasticity-toughness is high Gold.

The technical solution adopted in the present invention is: a kind of thin brilliant high tough beta-titanium alloy, in this titanium alloy, each element is according to matter Amount percentage ratio is the Al of 3.0% ~ 7.0%, the Mo of 4% ~ 9%, the V of 7% ~ 9%, the Cr of 2% ~ 5%, 0.5% ~ 1% Sn, the Zr of 1% ~ 3%, surplus is Ti and inevitable impurity element, and the crystal grain of this titanium alloy is less than 3 microns.The present invention Thin brilliant high tough beta-titanium alloy be that the intensity being mingled with venation stricture of vagina bar that a kind of crystal grain is fine and closely woven is high, plasticity is big, that toughness is strong is comprehensive The alloy that energy is strong.

A kind of method making thin brilliant high tough beta-titanium alloy, is carried out according to the steps:

Step one: weigh raw material, weighs titanium sponge, rafifinal, pure tin ingot, pure zirconium, aluminum chromium, aluminium molybdenum alloys and aluminum-vanadium alloy As raw material, making in gross mass, each element is the Al of 3.0% ~ 7.0% according to mass percent, the Mo of 4% ~ 9%, 7% ~ The V of 9%, the Cr of 2% ~ 5%, the Sn of 0.5% ~ 1%, the Zr of 1% ~ 3%；

Step 2, melting ingot casting, join melting in vacuum induction magnetic levitation melting stove the raw material weighed in step one, then Furnace cooling, obtains ingot casting；

Step 3, isothermal forging, the ingot casting obtained in step 2 first more than alpha+beta/beta transformation point 100 DEG C ~ 150 DEG C carry out One takes turns isothermal die forging process, then carries out second take turns isothermal die forging process alpha+beta/beta transformation point above and below 30 DEG C ~ 100 DEG C；Pass through First round isothermal die forging process makes crystalline phase tissue become fine and closely woven, during taking turns isothermal die forging process second, more than alpha+beta/beta transformation point 30 DEG C ~ 100 DEG C carry out second and take turns isothermal die forging process, make the intensity of alloy structure significantly increase, below alpha+beta/beta transformation point 30 DEG C ~ 100 DEG C carry out second and take turns isothermal die forging process, make the toughness of alloy structure be obviously enhanced.

Step 4, fixation rates, the ingot casting through step 3 isothermal forging, first below alpha+beta/beta transformation point 20 DEG C ~ 100 DEG C carry out 0.5 ~ 2h solution treatment, then below alpha+beta/beta transformation point 100 DEG C ~ 400 DEG C carry out at 4 ~ 10h timeliness Reason, i.e. obtains thin brilliant high tough beta-titanium alloy.By fixation rates, add plasticity and the intensity of alloy, in step 3 More than alpha+beta/beta transformation point 30 DEG C ~ 100 DEG C plasticity carrying out the second alloy taking turns isothermal die forging process have obtained improving on a large scale, step In three, below alpha+beta/beta transformation point, 30 DEG C ~ 100 DEG C intensity carrying out the second alloy taking turns isothermal die forging process have obtained increasing on a large scale By force.

As a kind of optimal way: the isothermal die forging process in step 3 refers to ingot casting be set up three-dimensional coordinate system, first Forging along X-axis, making along X-axis contracting amount is original half, forges then along Y-axis, and making along Y-axis contracting amount is original half, Forging finally along Z axis, making along Z axis contracting amount is original half.

As a kind of optimal way: the fixation rates in step 4 is placed in eddy current field and processes.Pass through The fixation rates of eddy current field effect forms venation stricture of vagina bar, not only significantly improves plasticity and the toughness of alloy, Er Qieti High intensity.

It is that β phase exists when this alloy is more than alpha+beta/beta transformation point, is alpha+beta phase time below alpha+beta/beta transformation point, at α It is more than+β/beta transformation point that quick water-cooled can make the β phase of formation remain.

The invention has the beneficial effects as follows: the intensity-plasticity of the thin brilliant high tough beta-titanium alloy that the present invention provides-toughness coupling Performance is high.

Detailed description of the invention

Thin brilliant high tough beta-titanium alloy in the present embodiment is high tough titanium alloy T i-4Al-1Sn-2Zr-5Mo-8V- 2.5Cr, crystal grain is less than 3 microns.

Its preparation method is as follows:

Step one, weigh raw material, weigh titanium sponge, fine aluminium, pure chromium, pure tin, pure zirconium respectively, (Mo content 7 is aluminium molybdenum alloys 73.01%) and aluminum-vanadium alloy (V content is 83.06%) amount to 18000g as raw material, make to meet in gross mass, according to quality Percentage ratio be 4% Al, the Mo of 5%, the V of 8%, the Cr of 2.5%, the Sn of 1%, the Zr of 2%, surplus be Ti and not Evitable impurity；

Step 2,

Melting ingot casting: the titanium sponge weighed through step one, fine aluminium, pure chromium, pure tin, pure zirconium, aluminium molybdenum alloys and aluminum-vanadium alloy are added Enter melting, then furnace cooling in vacuum induction magnetic levitation melting stove, obtain ingot casting；Being sized alpha+beta/beta transformation point is 790 ℃；

Step 3,

Isothermal forging: 1. cut stock of square from ingot casting；2. first carry out taking turns isothermal cogging die forging at 960 DEG C, particularly as follows: first First forging titanium alloy along X direction of principal axis, specimen height reduces about 50%, and (the referred to herein as first forging work step, is designated as 1P)；Spinning sample carries out second time along its long axis direction and forges, and specimen height reduces about 50% equally, and (this is the second forging Work step, is designated as 2P)；Continue spinning sample and forge (this is the 3rd forging work step, is designated as 3P) along its long axis direction, above-mentioned 3 Multiway forging is taken turns in the forging of individual work step referred to as.3. carry out second at 850 DEG C and take turns isothermal die forging process.

Step 4,

Fixation rates machine performance:

Carry out solid solution the most at different temperatures, do not carry out Ageing Treatment corresponding performance such as following table (solid solution 1h):

First solid solution 50min at 750 DEG C, then Ageing Treatment 7h the most at different temperatures, its performance such as following table:

Process if placed in eddy current field during fixation rates, by the fixation rates of eddy current field effect Form venation stricture of vagina bar, not only significantly improve plasticity and the toughness of alloy, and improve intensity.

Claims

1. the high tough beta-titanium alloy of thin crystalline substance, it is characterised in that: in this titanium alloy each element according to mass percent be 3.0% ~ The Al of 7.0%, the Mo of 4% ~ 9%, the V of 7% ~ 9%, the Cr of 2% ~ 5%, the Sn of 0.5% ~ 1%, the Zr of 1% ~ 3%, Surplus is Ti and inevitable impurity element, and the crystal grain of this titanium alloy is less than 3 microns.

2. the method for the thin brilliant high tough beta-titanium alloy made described in claim 1, it is characterised in that according to the steps Carry out:

Step 3, isothermal forging, the ingot casting obtained in step 2 first more than alpha+beta/beta transformation point 100 DEG C ~ 150 DEG C carry out One takes turns isothermal die forging process, then carries out second take turns isothermal die forging process alpha+beta/beta transformation point above and below 30 DEG C ~ 100 DEG C；

Step 4, fixation rates, the ingot casting through step 3 isothermal forging, first below alpha+beta/beta transformation point 20 DEG C ~ 100 DEG C carry out 0.5 ~ 2h solution treatment, then below alpha+beta/beta transformation point 100 DEG C ~ 400 DEG C carry out 4 ~ 10h Ageing Treatment, I.e. obtain thin brilliant high tough beta-titanium alloy.

The method of a kind of thin brilliant high tough beta-titanium alloy made described in claim 1 the most according to claim 2, it is special Levy and be: the isothermal die forging process in step 3 refers to ingot casting is set up three-dimensional coordinate system, forge first along X-axis, make along X-axis Contracting amount is original half, forges then along Y-axis, and making along Y-axis contracting amount is original half, forges finally along Z axis, makes edge Z axis contracting amount is original half.

The method of a kind of thin brilliant high tough beta-titanium alloy made described in claim 1 the most according to claim 2, it is special Levy and be: the fixation rates in step 4 is placed in eddy current field and processes.