阅读说明：本技术 一种微合金化高强韧动密封材料及其制备方法 (Microalloyed high-toughness dynamic sealing material and preparation method thereof ) 是由 周亮 于 2020-06-30 设计创作，主要内容包括：本发明涉及一种微合金化高强韧动密封材料及其制备方法,该材料的成分为(CoNiFe)<Sub>90</Sub>Al<Sub>10-x</Sub>Ti<Sub>x</Sub>,其中Co、Ni、Fe按等原子配比,x的取值范围为1～9。该合金的制备工艺路线为：真空电弧熔炼—均匀化退火—锻造(热锻)—均匀化退火—轧制(冷轧)—退火热处理。首先,将Co、Ni、Fe、Al和Ti粒/块按比配料,采用真空电弧熔炼法熔炼成锭并进行均匀化退火；其次,将铸锭加热到一定温度后,进行锻造成型,随后进行均匀化退火；最后通过轧制(冷轧)将锻态合金制备成板材并进行退火热处理。合理的塑性加工和退火热处理工艺可以提高合金的强韧性,采用本发明制备的微合金化高强韧合金材料可广泛适用于动密封材料领域。(The invention relates to a microalloyed high-strength and high-toughness dynamic sealing material and a preparation method thereof, wherein the material comprises the following components (CoNiFe) 90 Al 10‑x Ti x Wherein Co, Ni and Fe are in equal atomic ratio, and the value range of x is 1-9. The preparation process route of the alloy is as follows: vacuum arc melting, homogenizing annealing, forging (hot forging), homogenizing annealing, rolling (cold rolling), and annealing heat treatment. Firstly, proportioning Co, Ni, Fe, Al and Ti particles/blocks according to a certain proportion, smelting into ingots by adopting a vacuum arc melting method, and carrying out homogenization annealing; secondly, heating the cast ingot to a certain temperature, forging and forming, and then carrying out homogenizing annealing; and finally, rolling (cold rolling) the forged alloy to prepare a plate and carrying out annealing heat treatment. Reasonable plastic working and annealing heat treatment process can improve the toughness of the alloyThe microalloyed high-toughness alloy material prepared by the method can be widely applied to the field of dynamic sealing materials.)

1. A microalloyed high-toughness dynamic sealing material and a preparation method thereof are characterized in that the dynamic sealing material comprises (CoNiFe)₉₀Al_10-xTi_xWherein Co, Ni and Fe are in equal atomic ratio, and the value range of x is 1-9.

2. The microalloyed high-toughness dynamic sealing material and the preparation method thereof as claimed in claim 1, wherein the preparation method comprises the following steps:

step 1, mixing Co, Ni, Fe, Al and Ti particles/blocks according to 30 percent of Co, 30 percent of Ni, 30 percent of Fe, 1 to 9 percent of Ti and the balance of Al, placing the mixture into a vacuum arc furnace, and vacuumizing to 1 × 10^-2～1×10^-3Pa, the protective gas is argon, and the pressure in the furnace is 0.05-0.06 MPa; continuously overturning and remelting for at least 5 times in the smelting process, smelting into ingots, and carrying out homogenization annealing on the as-cast alloy ingots;

step 2, forging the cast alloy ingot after the homogenization annealing, and carrying out homogenization annealing on the forged alloy block;

and 3, rolling the forged alloy block, and carrying out annealing heat treatment on the rolled alloy block.

3. The microalloyed high-strength and high-toughness dynamic seal material and the preparation method thereof as claimed in claim 2, wherein the Co, Ni, Fe, Al and Ti grains/blocks in the step 1) have a purity of 99.97 wt.%, and are smelted by vacuum arc smelting, and the smelting current value range is 100-300A.

4. The microalloyed high-strength and high-toughness dynamic sealing material and the preparation method thereof as claimed in claim 3, wherein the homogenization annealing in the step 1) is carried out at 900-1100 ℃ for 12-24 h, and the cooling mode is furnace cooling.

5. The microalloying high strength and toughness dynamic seal material and the preparation method thereof according to claim 3 or 4, characterized in that the forging process in the step 2) is to heat an as-cast alloy ingot to 800-1000 ℃, place the alloy ingot on a platform, and perform multiple forging for 5-10 times by using a forging machine.

6. The microalloyed high-strength and high-toughness dynamic seal material and the preparation method thereof as claimed in claim 5, wherein the homogenization annealing temperature range in the step 2) is 900-1100 ℃, the heat preservation time is 1-12 h, and the cooling mode is air cooling.

7. The microalloyed high-toughness dynamic seal material and the preparation method thereof according to claim 6, wherein the rolling process in the step 3) is characterized in that the forging block is rolled at room temperature according to the relative reduction of 10%, 20%, 40%, 60%, 75%, 85% and 90% relative to the thickness of the original forging block, and finally a plate with the thickness of 1.0-2.5 mm is obtained.

8. The microalloyed high-strength and high-toughness dynamic seal material and the preparation method thereof as claimed in claim 6, wherein the annealing temperature in the step 3) is 600-1100 ℃, the temperature is kept for 1-12 h, and air cooling is carried out.

Technical Field

The invention relates to a preparation method of a dynamic sealing material, in particular to a microalloyed high-strength and high-toughness dynamic sealing material and a preparation method thereof, belonging to the technical field of dynamic sealing materials.

Background

The dynamic seal is an important part of an aircraft engine and other turbomachines, and is widely applied to the fields of various aircraft engines, aeroderivative gas turbines, steam turbines, heavy-duty gas turbines, nuclear power units and the like. Dynamic seal materials typically operate under special conditions of high rotational speed, high ambient temperature, or high frictional heating, which requires high toughness. The new alloy design concept provides that 5 or more than 5 elements are provided, and the alloy with 5 to 35 percent of each element in atomic percent is a high-entropy alloy, namelyA multi-principal element alloy. In addition, high entropy alloys may also be defined in terms of entropy. Thermodynamically, entropy is a parameter that characterizes the degree of system chaos. The larger the degree of chaos, the larger the entropy of the system. Alloy materials can be divided into the following three major categories: low entropy alloys, i.e. conventional alloys, having one or two elements as the main constituent element (Δ S)_mixLess than or equal to 0.69R); a medium entropy alloy comprising two to four main elements (0.69R. ltoreq. DELTA.S)_mixLess than or equal to 1.61R); high entropy alloy comprising at least five main constituent elements (Δ S)_mix≥1.61R)。

The medium-entropy alloy is between the traditional alloy (low-entropy alloy) and the high-entropy alloy, so that the outstanding performances of the high-entropy alloy, such as high strength and hardness, are maintained, the number of principal elements is reduced, the mixed entropy of the medium-entropy alloy is closer to that of the traditional alloy, and the medium-entropy alloy has better plastic processing performance.

At present, the preparation method of the entropy alloy in the block mainly comprises a vacuum arc melting method and a powder metallurgy method. The vacuum arc melting method can be used for melting the alloy with higher melting point, and can be used for melting more alloys at one time, so that volatile impurities and certain gases can be effectively removed. However, the cast alloy prepared by the method is easy to have the defects of large internal stress, component segregation, pores, shrinkage cavities and the like. Due to the complex deformation mechanism, most of the related researches on the medium entropy alloy are focused on the casting state. At present, the subsequent processing technology of the as-cast medium entropy alloy mainly comprises two processes of forging and rolling. The defects of casting state looseness and the like can be eliminated by forging, and the microstructure is optimized, so that the mechanical property of the workpiece is generally superior to that of a casting made of the same material. The mechanical properties of the workpiece prepared by rolling are poor, the hardness is too high, and the mechanical properties can be recovered only by annealing.

The medium-entropy alloy has not received wide attention as a new alloy system, and relatively few reports of the influence of corresponding plastic deformation on the structure and the performance of the medium-entropy alloy exist. The method has the advantages that alloy components are reasonably designed, technological parameters of plastic deformation (forging and rolling) are optimized, the plastic deformation capacity of the medium-entropy alloy is continuously improved, and the method is an important direction for medium-entropy alloy research in the future. In order to improve the obdurability of the CoNiFe medium-entropy alloy, the medium-entropy alloy with better comprehensive performance is prepared by adding trace Al and Ti and performing plastic processing and annealing heat treatment at different temperatures. The microalloyed high-toughness medium-entropy alloy prepared by the method can be widely applied to the field of dynamic sealing materials.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a microalloyed high-toughness dynamic sealing material and a preparation method thereof, wherein the dynamic sealing material comprises (CoNiFe)₉₀Al_10-xTi_xThe alloy is prepared by a vacuum arc melting method, technological parameters of forging, rolling and annealing heat treatment are optimized, the toughness of the alloy is improved, the medium-entropy alloy with excellent comprehensive performance is prepared, and the alloy can be widely applied to the field of dynamic sealing materials.

In order to achieve the purpose, the technical scheme of the invention is as follows, the microalloyed high-strength and high-toughness dynamic sealing material comprises (CoNiFe) as a component and the preparation method thereof₉₀Al_10-xTi_xWherein Co, Ni and Fe are in equal atomic ratio, and the value range of x is 1-9.

The preparation method comprises the following steps:

step 1, mixing Co, Ni, Fe, Al and Ti particles/blocks according to 30 percent of Co, 30 percent of Ni, 30 percent of Fe, 1 to 9 percent of Ti and the balance of Al, placing the mixture into a vacuum arc furnace, and vacuumizing to 1 × 10^-2～1×10^-3Pa, the protective gas is argon, and the pressure in the furnace is 0.05-0.06 MPa; continuously overturning and remelting for at least 5 times in the smelting process, smelting into ingots, and carrying out homogenization annealing on the as-cast alloy ingots;

step 2, forging the cast alloy ingot after the homogenization annealing, and carrying out homogenization annealing on the forged alloy block;

and 3, rolling the forged alloy block, and carrying out annealing heat treatment on the rolled alloy block.

Wherein the content of the first and second substances,

the purity of Co, Ni, Fe, Al and Ti grains/blocks in the step 1) is 99.97 wt.%, the smelting is vacuum arc smelting, and the value range of the smelting current is 100-300A.

And (2) carrying out homogenizing annealing at the temperature of 900-1100 ℃, keeping the temperature for 12-24 h, and cooling in a furnace.

And 2) heating the as-cast alloy ingot to 800-1000 ℃, placing the alloy ingot on a platform, and forging the alloy ingot for multiple times by using a 20-40 kg forging machine.

The temperature range of the homogenizing annealing in the step 2) is 900-1100 ℃, the heat preservation time is 1-12 h, and the cooling mode is air cooling.

And 3) rolling the forging block at room temperature according to the relative rolling reduction of 10%, 20%, 40%, 60%, 75%, 85% and 90% relative to the thickness of the original forging block, and finally obtaining the plate with the thickness of 1.0-1.5 mm.

And 3) annealing, wherein the temperature range is 600-1100 ℃, the heat preservation time is 1-12 h, and air cooling is carried out.

Compared with the prior art, the invention has the following advantages that 1) the entropy alloy in CoNiFe has better plasticity but poorer strength and toughness at room temperature. The invention adds trace Al and Ti with larger relative atomic radius, the total content is 10 percent, and the invention mainly enhances the solid solution strengthening effect; 2) on the basis of ensuring that the matrix phase is a single-phase FCC structure, the precipitation of a strengthening phase is regulated and controlled through the change of the content of Al/Ti, so that the strength is improved and the good plasticity of the material is ensured. Simultaneously, different heat treatment processes are adopted to control the form and the quantity of precipitated phases; 3) the invention improves the structure and performance of the medium-entropy alloy through forging, rolling and proper heat treatment, improves the obdurability of the medium-entropy alloy and has better comprehensive performance.

The specific implementation mode is as follows:

the following detailed description of the invention is provided to facilitate an understanding of the invention.