阅读说明：本技术 一种铌条的制备工艺 (Preparation process of niobium strip ) 是由 马振元 于 2019-11-18 设计创作，主要内容包括：本发明公开了一种铌条的制备工艺,采用铝热还原法,包括以下具体步骤：a、配料；b、混料；c、还原反应；d、真空加热；e、成型；f、真空烧结。通过上述,本发明的铌条的制备工艺,在无需提纯的情况下,经过还原反应、真空加热及真空烧结,由于真空加热时的连续多次升温保温的加热处理,Al、Al<Sub>2</Sub>O和NbO从铌铝热剂中挥发出去,使得所制得的铌条纯度更高,就能显著降低各项杂质的含量,缩短了工艺流程,操作简单,成本低,又利于环境治理的生产,满足了满足客户的要求。(The invention discloses a preparation process of a niobium strip, which adopts an aluminothermic reduction method and comprises the following specific steps: a. preparing materials; b. mixing materials; c. carrying out reduction reaction; d. heating in vacuum; e. molding; f. and (4) vacuum sintering. Through the above, the preparation process of the niobium strip of the invention is subjected to reduction reaction, vacuum heating and vacuum sintering without purification, and due to continuous heating treatment of temperature rise and heat preservation for multiple times during vacuum heating, Al and Al 2 The O and the NbO volatilize from the niobium thermite, so that the purity of the prepared niobium bar is higher, the content of various impurities can be obviously reduced, the process flow is shortened, the operation is simple,low cost, is beneficial to the production of environmental management and meets the requirements of customers.)

1. The preparation process of the niobium strip is characterized by adopting an aluminothermic reduction method and comprising the following specific steps of:

a. preparing materials, namely preparing niobium oxide and aluminum powder, wherein the aluminum powder is 30-150 meshes of aluminum powder;

b. mixing materials, namely uniformly mixing niobium oxide and aluminum powder, pouring the mixture into a crucible, and then covering a layer of aluminum powder on the mixture of niobium oxide and aluminum powder;

c. a reduction reaction, namely heating the crucible to 800-;

d. vacuum heating, cooling the obtained niobium thermite to 60-80 ℃, then placing the niobium thermite into a vacuum furnace for secondary heating reduction, wherein the temperature in the vacuum furnace is increased to 1050-₂Volatilizing O and NbO from the niobium thermite to obtain high-purity spongy niobium;

e. forming, namely pressing and forming the obtained spongy niobium, and drying the formed material;

f. and (4) vacuum sintering, namely performing vacuum sintering treatment on the dried and formed material to obtain the niobium strip.

2. The process for preparing the niobium strip as claimed in claim 1, wherein the mass percentages of the niobium oxide and the aluminum powder in the step a are as follows: 94-98% of niobium oxide and 2-6% of aluminum powder.

3. The process for producing the niobium strip as claimed in claim 2, wherein the niobium oxide is a 99% pure niobium oxide.

4. The process for preparing the niobium strip as claimed in claim 1, wherein the temperature for the vacuum sintering in step f is 1000-1400 ℃, and the sintering time is 2-5 hours.

5. The process for producing the niobium strip as claimed in claim 1, wherein the niobium content in the niobium strip in the step f is 99.5 to 99.8% by mass.

Technical Field

The invention belongs to the technical field of metal preparation processes, and particularly relates to a niobium strip preparation process.

Background

The niobium strip product is a strip product made of high-purity metal niobium, and can be used as an additive of iron-based, nickel-based and zirconium-based superalloys to improve the strength performance of the niobium strip product. Niobium and niobium alloy are high temperature resistant materials, and among tungsten, molybdenum, tantalum and niobium of four space metals in aerospace, the niobium alloy has the best comprehensive performance, and has good plasticity and excellent processing and welding performance. In recent years, with the continuous development of the aviation and aerospace industries, the application range of the niobium-containing alloy is further expanded, and the niobium-containing alloy is widely applied to structural components of airplanes and rocket engines and materials of heat protection systems. The above-mentioned application under severe conditions puts higher demands on the quality of niobium-containing alloys, particularly niobium strips, which are one of the important raw materials.

Disclosure of Invention

The invention mainly solves the technical problem of providing a niobium strip preparation process, the prepared niobium strip has high purity, does not need purification treatment, shortens the process flow, is simple to operate and low in cost, is beneficial to production of environmental management, and meets the requirements of customers.

In order to solve the technical problems, the invention adopts a technical scheme that: the preparation process of niobium strip by aluminothermic reduction comprises the following steps:

a. preparing materials, namely preparing niobium oxide and aluminum powder, wherein the aluminum powder is 30-150 meshes of aluminum powder;

b. mixing materials, namely uniformly mixing niobium oxide and aluminum powder, pouring the mixture into a crucible, and then covering a layer of aluminum powder on the mixture of niobium oxide and aluminum powder;

c. a reduction reaction, namely heating the crucible to 800-,

d. vacuum heating, cooling the obtained niobium thermite to 60-80 ℃, putting the niobium thermite into a vacuum furnace for secondary heating reduction, wherein the temperature in the vacuum furnace is increased to 1050-The temperature in the vacuum furnace is increased to 1750-₂Volatilizing O and NbO from the niobium thermite to obtain high-purity spongy niobium;

e. forming, namely pressing and forming the obtained spongy niobium, and drying the formed material;

f. and (4) vacuum sintering, namely performing vacuum sintering treatment on the dried and formed material to obtain the niobium strip.

In a preferred embodiment of the present invention, the mass percentages of the niobium oxide and the aluminum powder in step a are as follows: 94-98% of niobium oxide and 2-6% of aluminum powder.

In a preferred embodiment of the present invention, the niobium oxide is niobium oxide with a purity of 99%.

In a preferred embodiment of the present invention, the temperature during the vacuum sintering in step f is 1000-1400 ℃, and the sintering time is 2-5 hours.

In a preferred embodiment of the present invention, the niobium content of the niobium strip in step f is 99.5 to 99.8% by mass.

The invention has the beneficial effects that: the preparation process of the niobium strip of the invention comprises reduction reaction, vacuum heating and vacuum sintering without purification, and because of continuous and repeated heating treatment of temperature rise and heat preservation during vacuum heating, Al and Al₂O and NbO volatilize from the niobium thermite, so that the purity of the prepared niobium strip is higher, the content of various impurities can be obviously reduced, the process flow is shortened, the operation is simple, the cost is low, the production of environmental management is facilitated, and the requirements of customers are met.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without inventive efforts, wherein:

fig. 1 is a flow chart of a process for making niobium strip of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1, an embodiment of the present invention includes:

a preparation process of a niobium strip adopts an aluminothermic reduction method and comprises the following specific steps:

a. preparing materials, namely preparing niobium oxide and aluminum powder, wherein the aluminum powder is 30-150 meshes of aluminum powder;

b. mixing materials, namely uniformly mixing niobium oxide and aluminum powder, pouring the mixture into a crucible, and then covering a layer of aluminum powder on the mixture of niobium oxide and aluminum powder;

c. a reduction reaction, namely heating the crucible to 800-;

d. vacuum heating, cooling the obtained niobium thermite to 60-80 ℃, then placing the niobium thermite into a vacuum furnace for secondary heating reduction, wherein the temperature in the vacuum furnace is increased to 1050-₂Volatilizing O and NbO from the niobium thermite to obtain high-purity spongy niobium;

e. forming, namely pressing and forming the obtained spongy niobium, and drying the formed material;

f. and (4) vacuum sintering, namely performing vacuum sintering treatment on the dried and formed material to obtain the niobium strip.

In the above, the mass percentages of the niobium oxide and the aluminum powder in the step a are as follows: 94-98% of niobium oxide and 2-6% of aluminum powder. Wherein the niobium oxide is niobium oxide with a purity of 99%.

Because the aluminum powder with a 30-150 mesh sieve and the niobium oxide with the purity of 99 percent are adopted, the porosity of the niobium thermite is reduced, the niobium thermite with higher purity can be prepared, and the niobium thermite is subjected to continuous and multiple heating treatment of temperature rise and heat preservation through vacuum heating, and Al are added₂O and NbO volatilize from the niobium thermite to obtain high-purity spongy niobium, so that the original purification link is reduced, and the problem that the reaction position is difficult to control in the purification link is solved.

The sponge niobium product has easily controlled shape, can be formed by simple pressing, is suitable for being made into semi-finished products with various shapes, and then is solidified into the required niobium strip after vacuum sintering.

Furthermore, the temperature during the vacuum sintering in the step f is 1000-.