阅读说明：本技术 一种高强度高塑性ZrTiAlNb锆基合金及其制备方法 (High-strength and high-plasticity ZrTiAlNb zirconium-based alloy and preparation method thereof ) 是由 周云凯 张宴会 于 2020-07-23 设计创作，主要内容包括：本发明公开一种高强度高塑性ZrTiAlNb锆基合金及其制备方法。所述锆基合金由质量百分比：锆35％-45％、钛58％-40％、铝4％--3％、铌3-2％的元素组成。其制备方法是：将原料表面清除干净后,混合均匀制成电极,放入自耗型熔炼炉中,在惰性气体保护下反复熔炼成合金铸锭,高温退火后,在轧机上进行多道次热轧变形,单道次变形量不低于10％,最终变形量不低于70％,每道次间需将合金上下翻转,并回炉保温。之后,将合金板材进行淬火处理,在合金微观组织结构中得到大量纳米孪晶。本发明的抗拉强度可达到1135MPa,延伸率可达到7.2％,并具有较小的热膨胀系数和良好的耐辐照和原子氧腐蚀性能等优点,符合空间活动构件用结构材料的基本要求。(The invention discloses a high-strength high-plasticity ZrTiAlNb zirconium-based alloy and a preparation method thereof. The zirconium-based alloy comprises the following components in percentage by mass: 35-45% of zirconium, 58-40% of titanium, 4-3% of aluminum and 3-2% of niobium. The preparation method comprises the following steps: cleaning the surface of the raw materials, uniformly mixing to prepare an electrode, putting the electrode into a consumable smelting furnace, repeatedly smelting to form an alloy ingot under the protection of inert gas, carrying out multi-pass hot rolling deformation on a rolling mill after high-temperature annealing, wherein the single-pass deformation is not less than 10%, the final deformation is not less than 70%, the alloy is required to be turned over up and down during each pass, and the alloy is returned to the furnace for heat preservation. And then, quenching the alloy plate to obtain a large amount of nano twin crystals in the microstructure of the alloy. The tensile strength of the invention can reach 1135MPa, the elongation can reach 7.2%, and the invention has the advantages of smaller thermal expansion coefficient, good radiation resistance and atomic oxygen corrosion resistance, and the like, and meets the basic requirements of structural materials for space activity components.)

1. A high-strength and high-plasticity ZrTiAlNb zirconium-based alloy and a preparation method thereof are characterized in that: the zirconium-based alloy comprises the following components in percentage by mass: the alloy comprises, by weight, 35-45% of zirconium, 58-40% of titanium, 4-3% of aluminum and 3-2% of niobium, wherein the tensile strength of the zirconium-based alloy is 1063-1135 MPa, the elongation rate can reach more than 7%, and the zirconium-based alloy has better comprehensive mechanical properties compared with 9Cr18 steel and TC4 titanium alloy, and simultaneously has low density and good corrosion resistance.

2. The preparation method of the high-strength high-plasticity ZrTiAlNb alloy according to claim 1, which is characterized by comprising the following steps: the preparation method comprises the following steps:

preparing raw materials in step (1):

the weight percentages are as follows: performing surface pickling and oxidation removal treatment on raw materials of 35-45% of zirconium, 58-50% of titanium, 4-3% of aluminum and 3-2% of niobium, then sequentially cleaning the raw materials by using a weak alkaline solution and absolute ethyl alcohol, finally removing surface residues by using an ultrasonic instrument, and finally quickly drying the raw materials by using a drying oven to keep the raw materials dry;

step (2) electrode manufacturing:

after metal raw materials are uniformly mixed, pressing the metal raw materials into electrode rods for smelting by using special equipment;

step (3), alloy ingot casting:

the prepared electrode bar is put into a consumable smelting furnace to be smelted, and the furnace chamber is internally vacuumized in a grading way to 10^-5The degree of vacuum is graded, inert gas is filled into the alloy ingot to form protective atmosphere, and the alloy ingot needs to be smelted for multiple times to ensure uniform smelting;

step (4), homogenizing and annealing:

before further processing, the alloy ingot needs to be subjected to high-temperature long-time homogenizing annealing in a protective atmosphere, so that the components of the alloy ingot are further homogenized, the homogenizing annealing temperature is controlled to be 950-1000 ℃, and the annealing time is determined according to the standard of 30 min/kg;

step (5), hot working deformation:

firstly, a plastic deformation processing technology is a key link for preparing the high-strength and high-plasticity zirconium-based alloy, and an alloy ingot is heated by adopting a box-type resistance furnace at the temperature of 600-750 ℃;

before the first rolling deformation, the heat preservation time is determined according to the size of an alloy ingot, the alloy ingot with the weight less than 5kg is controlled to be 30-50 minutes, and the heat preservation time is increased according to 10min/kg when the weight of the alloy ingot exceeds 5 kg;

rolling deformation needs to adopt a multi-pass rolling deformation process, the single-pass reduction deformation is not less than 10%, after each pass of rolling, the alloy ingot is turned over up and down, returned to the furnace and kept warm, the next pass of rolling is carried out, and finally the reduction deformation needs to reach more than 70%;

fourthly, the time of returning and holding for each pass is determined according to the size of the alloy ingot, the weight of the alloy ingot less than 5kg is controlled within 3-7 minutes, and the time of holding more than 5kg is increased according to 5 min/kg; the heat preservation time between each pass of plastic deformation needs to be strictly controlled, and the recovery of the alloy structure can be caused by overlong time for holding the temperature in the melting furnace, so that the final performance of the alloy plate is influenced;

water quenching, quick cooling and cleaning:

after the rolling plastic deformation process, the alloy plate is immediately immersed in water, the temperature is rapidly reduced by adopting a water quenching mode, a large amount of nanometer twin crystals are prepared in an alloy microstructure by utilizing the interaction of plastic deformation and rapid cooling, finally, the high-strength high-plasticity zirconium-based alloy plate is obtained, the oxide skin is removed from the surface of the zirconium-based alloy plate, and the series of ZrTiAlNb zirconium-based alloys are obtained after cleaning.

Technical Field

The invention discloses a high-strength high-plasticity ZrTiAlNb zirconium-based alloy and a preparation method thereof, belonging to the technical field of preparation of new materials.

Background

Alloy steel (stainless steel, GCr15, 20CrMnTi) and TC4 titanium alloy are two alloy material systems which are widely applied to the aerospace field at present, and have long practical application history. However, with the development of technology, the requirement for space exploration is increased, and both material systems have unsatisfactory aspects in performance. The alloy steel material system generally has the problems of high density, large influence by alternating temperature, easy influence on dimensional precision and low specific strength, and has poor irradiation resistance and atomic oxygen corrosion resistance. The TC4 titanium alloy has the problems of low strength, low wear resistance, unsatisfactory dimensional stability and the like. Therefore, a new alloy system is urgently needed to be searched as a substitute material, meet the increasing use requirements of space moving components, and promote the development of the field of aerospace materials. Zirconium alloy has been widely used in the fields of nuclear energy, chemical industry and the like, and is expected to become a new alloy material for space moving components in the field of aerospace due to the small thermal expansion coefficient and good radiation and atomic oxygen corrosion resistance.

Disclosure of Invention

The invention aims to provide a high-strength high-plasticity ZrTiAlNb zirconium-based alloy and a preparation method thereof. The ZrTiAlNb zirconium-based alloy is mainly used as a research object, and the alloy structure microstructure is purposefully adjusted through a series of processing methods with strictly controlled parameters, so that the ZrTiAlNb zirconium-based alloy with high strength and high plasticity is prepared.

The technical scheme adopted by the invention is as follows:

the zirconium-based alloy comprises the following components in percentage by mass: the alloy comprises, by weight, 35-45% of zirconium, 58-40% of titanium, 4-3% of aluminum and 3-2% of niobium, wherein the tensile strength of the zirconium-based alloy is 1063-1135 MPa, the elongation rate can reach more than 7%, and the zirconium-based alloy has better comprehensive mechanical properties compared with 9Cr18 steel and TC4 titanium alloy, and simultaneously has low density and good corrosion resistance.

A preparation method of a high-strength and high-plasticity ZrTiAlNb zirconium-based alloy comprises the following steps:

preparing raw materials in step (1): the mass percentage is as follows; the method comprises the following steps of carrying out surface pickling and oxidation removal treatment on raw materials of 35-45% of zirconium, 58-50% of titanium, 4-3% of aluminum and 3-2% of niobium, then sequentially cleaning the raw materials with a weak alkaline solution and absolute ethyl alcohol, finally removing surface residues by using an ultrasonic instrument, and finally quickly drying the raw materials by using a drying oven to keep the raw materials dry.

Step (2) electrode manufacturing: after the metal raw materials are uniformly mixed, the mixture is pressed into an electrode rod for smelting by using special equipment.

Step (3), alloy ingot casting: the prepared electrode bar is put into a consumable smelting furnace to be smelted, and the furnace chamber is internally vacuumized in a grading way to 10^-5And (3) filling inert gas to form protective atmosphere in a vacuum degree, and carrying out multiple smelting processes on the alloy ingot to ensure uniform smelting.

Step (4), homogenizing and annealing: before further processing, the alloy ingot needs to be subjected to high-temperature long-time homogenizing annealing in a protective atmosphere, so that the components of the alloy ingot are further homogenized, the homogenizing annealing temperature is controlled at 950-1000 ℃, and the annealing time is determined according to the standard of 30 min/kg.

Step (5), hot working deformation:

firstly, the plastic deformation processing technology is a key link for preparing the high-strength and high-plasticity zirconium-based alloy, and the alloy ingot is heated by adopting a box-type resistance furnace at the heating temperature range of 600-750 ℃.

Before the first rolling deformation, the heat preservation time is determined according to the size of an alloy ingot, the alloy ingot with the weight less than 5kg is controlled to be 30-50 minutes, and the heat preservation time is increased according to 10min/kg when the weight of the alloy ingot exceeds 5 kg.

And thirdly, rolling deformation needs to adopt a multi-pass rolling deformation process, the single-pass reduction deformation is not less than 10%, after each pass of rolling, the alloy ingot is turned over up and down, returned to the furnace and kept warm, and then rolled for the next pass, and finally the reduction deformation needs to reach more than 70%.

Fourthly, the time of returning and holding for each pass is determined according to the size of the alloy ingot, the weight of the alloy ingot less than 5kg is controlled within 3-7 minutes, and the time of holding more than 5kg is increased according to 5 min/kg; the heat preservation time between each pass of plastic deformation needs to be strictly controlled, and the recovery of the alloy structure can be caused by the overlong time of the remelting heat preservation, so that the final performance of the alloy plate is influenced.

Water quenching, quick cooling and cleaning:

and after the rolling plastic deformation process is finished, immediately immersing the alloy plate into water, rapidly cooling by adopting a water quenching mode, finally obtaining the high-strength high-plasticity zirconium-based alloy plate, removing oxide skin on the surface of the zirconium-based alloy plate, and cleaning to obtain the series of ZrTiAlNb zirconium-based alloys.

The invention has the beneficial effects that: the invention obtains a large amount of nanometer twin crystal structures by a tissue regulation technology, thereby having higher tensile strength and better elongation percentage and being used as an aviation structural member material. The invention has high specific strength, good acid and alkali corrosion resistance and other excellent mechanical and physical and chemical properties. The preparation process is simple and easy to operate, and the zirconium-based alloy material has stable performance and can be used for industrial production. The ZrTiAlNb zirconium-based alloy obtained by the method has the tensile strength of more than 1100MPa and the elongation of more than 7 percent, and has better comprehensive mechanical properties compared with 9Cr18 steel and TC4 titanium alloy. Meanwhile, the zirconium-based alloy has the advantages of low density, good corrosion resistance and the like, and the application range of the zirconium-based alloy in the aerospace industry is expanded.

Detailed Description

The present invention is described in detail below by way of examples, which are intended to be illustrative only and not to be construed as limiting the scope of the invention, which is to be given the full breadth of the appended claims and any and all insubstantial modifications and variations thereof which are within the scope of the appended claims.