CN109881048B

CN109881048B - Preparation method of high-strength high-plasticity Ni-W-X alloy

Info

Publication number: CN109881048B
Application number: CN201910148138.9A
Authority: CN
Inventors: 谭成文; 刘志超; 于晓东; 聂志华; 王春旭; 厉勇; 刘少尊; 郝芳; 曹国鑫; 刘广发
Original assignee: Beijing Institute of Technology BIT
Current assignee: Beijing Institute of Technology BIT
Priority date: 2019-02-28
Filing date: 2019-02-28
Publication date: 2021-09-21
Anticipated expiration: 2039-02-28
Also published as: CN109881048A

Abstract

The invention relates to a preparation method of a high-strength high-plasticity Ni-W-X alloy, which comprises the following steps: the yield strength in the casting state is more than or equal to 500MPa, and the tensile strength is more than or equal to 800MPa, elongation of 30-50 percent, belongs to the technical field of metal material preparation, and when the raw material proportion is different, the density of the obtained casting alloy is 8.8-12.1 g/cm³The range is continuously adjustable. The forming process of the invention does not need forging and heat treatment, has important significance for industrial production, and can lead the alloy to have high strength, high plasticity and continuously adjustable density in a casting state through the selection of components and a preparation method.

Description

Preparation method of high-strength high-plasticity Ni-W-X alloy

Technical Field

The invention relates to a preparation method of a high-strength high-plasticity Ni-W-X alloy, which comprises the following steps: the alloy casting state yield strength is more than or equal to 500MPa, the tensile strength is more than or equal to 800MPa, the elongation percentage is 30-50%, the preparation method belongs to the technical field of metal material preparation, and when the raw material proportion is different, the density of the obtained casting alloy is 8.8-12.1 g/cm³The range is continuously adjustable.

Background

In modern wars, important military facilities such as command posts, weapons stores, etc. are often built underground, above which robust defense works are built. In order to combat such targets, the development and production of earth-boring projectiles for attacking subsurface targets began internationally from the 80's of the 20 th century. The earth-boring bullet warhead can be divided into a kinetic energy penetration warhead, a series penetration warhead, a new concept warhead and the like. The most mature of them is the kinetic energy penetration warhead. The action principle of the kinetic energy penetration warhead is that kinetic energy provided by high-speed flying of a projectile body is utilized to impact and invade a firm target and then detonate high-energy explosive inside the warhead to damage the target.

The common warhead structural material is formed by compounding high-strength steel and high-density tungsten or tungsten carbide, and the density of the steel ranges from 7 g/cm to 8g/cm³The density of tungsten or tungsten carbide is 19.2-19.3 g/cm³The density of the present stage kinetic energy penetration warhead is 9-12 g/cm³. In the penetration process of the structure, due to the difference of material properties, damage can occur at the joint, the penetration effect is reduced, and the warhead of the single alloy is favorable for maintaining the integrity of the penetration process of the projectile body. The density of W-Ni-Co alloy mentioned in patent CN201510567928 and CN201610853863.2 is 11-13 g/cm³However, the manufacturing process is complicated, and the cost is high because the casting requires deformation treatment (forging and rolling) and heat treatment.

Disclosure of Invention

The invention provides a preparation method of a high-strength and high-plasticity Ni-W-X alloy in order to overcome the defects of the prior art.

The purpose of the invention is realized by the following technical scheme.

The invention relates to a preparation method of a high-strength high-plasticity Ni-W-X alloy, wherein the raw materials of the casting alloy comprise a nickel-tungsten binary intermediate alloy, a Ni simple substance and an X simple substance;

the atomic percentage of tungsten in the nickel-tungsten binary intermediate alloy is 7 to 21 percent;

the purity of the Ni simple substance is not lower than 99%;

the purity of the X simple substance is not lower than 99%, and X is one or the mixture of more than two of Al, Ti, Zr and Nb;

the atomic percent of W in the casting alloy is 6-20%, the atomic percent of X is 5-15%, and the balance is Ni.

The method takes a nickel-tungsten binary intermediate alloy, nickel and a simple substance X as raw materials, adopts vacuum arc melting or vacuum induction melting according to a proper proportion to be uniform under the protection of inert gas, obtains alloy liquid after alloying, and obtains a primary alloy ingot by pouring and forming. And further carrying out electroslag remelting and directional solidification on the primary alloy ingot to obtain a final ingot.

A preparation method of a high-strength high-plasticity Ni-W-X alloy comprises the following steps:

step 1: stacking the raw materials of the alloy into a smelting furnace from bottom to top according to the sequence of melting points from low to high, vacuumizing the smelting furnace, and when the requirement of the vacuum degree is less than or equal to 1 x 10^-3Introducing protective gas after Pa, smelting and stirring to obtain an alloy ingot;

step 2: turning over the alloy ingot obtained in the step 1 (namely, turning the alloy ingot upside down), putting the alloy ingot into a smelting furnace, vacuumizing the smelting furnace, and when the requirement of the vacuum degree is less than or equal to 1 x 10^-3Introducing protective gas after Pa, smelting and stirring to obtain a primary as-cast alloy, wherein the step is to ensure uniform components;

and step 3: and (3) carrying out electroslag remelting and directional solidification on the primary as-cast alloy obtained in the step (2) to obtain the final as-cast alloy.

The protective gas in the step 1 is argon; the smelting temperature is 1450-1550 ℃;

the protective gas in the step 2 is argon; the smelting temperature is 1450-1550 ℃;

in the step 3, the equipment used in the electroslag remelting directional solidification process is ESR-CDS500 electroslag remelting directional solidification equipment of Beijing Steel research high-tech technical component, Inc.

Advantageous effects

(1) The yield strength of the as-cast alloy is more than or equal to 500MPa, the tensile strength is more than or equal to 800MPa, and the elongation is 35-50%;

(2) the method has simple steps, does not need forging and heat treatment, and is economical and practical;

(3) the density of the as-cast alloy is 8.8-12.1 g/cm³Within the range, the density requirement of the structural material of the warhead can be met.

(4) According to the invention, on the basis of a nickel-tungsten binary intermediate alloy, after an element X with a proper proportion is added, a fine grid is formed through the aggregation and segregation of the element X and nickel, so that the as-cast mechanical property of the alloy is obviously improved;

drawings

FIG. 1 shows Ni prepared in example₈₁W₁₀Al₉An X-ray diffraction (XRD) pattern of the alloy;

FIG. 2 shows Ni prepared in example₈₁W₁₀Al₉Metallographic photographs of the alloys;

FIG. 3 shows Ni prepared in example₈₁W₁₀Al₉Electron backscatter diffraction patterns (EBSD) of the alloy;

FIG. 4a shows Ni prepared in example₈₁W₁₀Al₉Energy spectrum (EDX) Ni element surface distribution of the alloy;

FIG. 4b shows Ni prepared in example₈₁W₁₀Al₉Energy spectrum (EDX) W elemental surface distribution of the alloy;

FIG. 4c shows Ni prepared in example₈₁W₁₀Al₉Energy spectrum (EDX) Al element surface distribution of the alloy;

FIG. 5 shows Ni prepared in example₈₁W₁₀Al₉Tensile engineering stress strain curve of the alloy.

Detailed Description

The invention is further illustrated with reference to the following figures and examples.

Example 1

A preparation method of a high-strength and high-plasticity Ni-W-X alloy comprises the following steps of preparing a casting alloy by using a nickel-tungsten binary intermediate alloy, a Ni simple substance and an X simple substance;

the atomic percentage of tungsten in the nickel-tungsten binary master alloy is 11%;

the purity of the Ni simple substance is not lower than 99.5%;

the purity of the X simple substance is not lower than 99.5 percent, and X is Al;

the cast alloy contains 10 atomic% of W, 9 atomic% of Al, and the balance of Ni.

Preparation of atomic ratio of Ni₈₁W₁₀Al₉The alloy comprises the following specific steps:

the method comprises the following steps: selecting 11 atomic percent of W Ni-11W intermediate alloy and 99.5% pure Ni and Al as raw materials, polishing the Ni-11W intermediate alloy and the Ni and Al simple substances by using No. 100 silicon carbide abrasive paper to obtain clean raw materials, ultrasonically cleaning the clean raw materials by using acetone to obtain 1000g of the Ni-11W intermediate alloy and the Ni and Al simple substances, and ultrasonically cleaning the cleaned raw materials again;

step two: stacking the Ni-11W intermediate alloy and the elementary substances of Ni and Al which are subjected to ultrasonic cleaning in a high-vacuum non-consumable arc melting furnace, stacking the Ni-11W intermediate alloy on the Al, stacking the Ni on the Ni-11W intermediate alloy, vacuumizing until the vacuum degree is less than or equal to 1 x 10^-3And (3) when Pa is needed, flushing argon gas for protection, heating to obtain an alloy solution, and uniformly stirring in a magnetic field to obtain an alloy ingot.

Step three: turning over the alloy ingot obtained in the step 2, then carrying out arc melting again, casting the alloy ingot into a mold to obtain primary as-cast alloy, and then carrying out electroslag remelting and directional solidification to obtain Ni₈₁W₁₀Al₉An as-cast alloy.

Using wire cutting process to obtain Ni₈₁W₁₀Al₉The alloy was cut, the sample size was 10 × 10 (unit: mm) when the density test was performed, the sample size was 4 × 3 (unit: mm) when the metallographic test was performed, the sample size was 10 × 3 (unit: mm) when the XRD test was performed, and the sample when the tensile test was performed was fabricated into a workpiece sample according to the regulations in the national standard GB/T-228.1-2010. Then inlaying, polishing and corroding metallographic samples, polishing and polishing density, XRD and tensile samples, and ultrasonically cleaning with acetone to obtain Ni₇₉W₁₂Al₉And (5) testing the sample to be tested.

The smelting equipment is a Dh1-2 type high vacuum non-consumable arc smelting furnace produced by Shenyang scientific instruments, Inc. of Chinese academy of sciences, and ESR-CDS500 electroslag remelting directional solidification equipment of Beijing steel, Gaokou Nakou, Inc., and other performance characterization equipment is as follows:

(1) phase analysis: the Rigaku SMARTLAB X-ray diffractometer has the working voltage of 40KV and the working current of 190Ma, and the X-ray source is Cu Ka rays;

(2) and (3) microstructure: OLYMPUS U-MSSP is adopted in a metallographic phase, TESCAN Mira3LMH is adopted in Electron Back Scattering Diffraction (EBSD), the scanning multiple is 300X, the working voltage is 20KV, the sample inclination is 70 degrees, HITACHI SU 8220 is adopted in energy spectrum surface scanning, the working voltage is 17KV, and the scanning time is 4.5 min;

(3) and (3) testing the density: METTLER TOLEDO sensitivity kit ME-DNY-43;

(4) quasi-static stretching: INSTRON 5966.

To the Ni₈₁W₁₀Al₉The density of the sample was measured and found to be 9.6g/cm³。

To the Ni₈₁W₁₀Al₉The sample was subjected to phase analysis, and its X-ray diffraction pattern is shown in FIG. 1. The alloy is a face-centered cubic structure and is a single-phase nickel-based solid solution.

To the Ni₈₁W₁₀Al₉The microstructure analysis of the alloy was carried out, and the optical photograph thereof is shown in FIG. 2, and it can be seen that the crystal grains were divided by a mesh having a diameter of 44 to 50 μm. Electron Back Scattering Diffraction (EBSD) is shown in fig. 3, which indicates that the average as-cast grain size is greater than 250 μm, and the energy spectrum is surface-scanned as shown in fig. 4a, 4b, and 4c, which indicates that nickel elements segregate inside the grains to form a grid, aluminum elements are enriched at the grid, and tungsten elements are enriched inside the grid.

To the Ni₈₁W₁₀Al₉The alloy sample is subjected to quasi-static tensile mechanical property test, the tensile stress-strain curve is shown in figure 5, and Ni can be known₈₁W₁₀Al₉The alloy has the room-temperature tensile yield strength of 595MPa, the tensile strength of 885MPa and the elongation after fracture of 45 percent.

Examples 2 to 18

Examples 2 to 18 adopt the same process route as example 1, only the alloy raw materials and components are different, and the mechanical property indexes of the detected alloy are shown in table 1.

TABLE 1 compositions and Properties of the alloys of examples 2-18

The present invention includes, but is not limited to, the above embodiments, and any equivalent substitutions or partial modifications made under the principle of the spirit of the present invention are considered to be within the scope of the present invention.

Claims

1. A preparation method of a high-strength high-plasticity Ni-W-X alloy is characterized by comprising the following steps: the raw materials for preparing the alloy comprise a nickel-tungsten binary intermediate alloy, a Ni simple substance and an X simple substance;

the X simple substance is Al;

the purity of the Ni simple substance is not lower than 99%; the purity of the X simple substance is not lower than 99%;

the preparation method of the high-strength and high-plasticity Ni-W-X alloy comprises the following steps:

step 1: stacking alloy raw materials into a smelting furnace from bottom to top according to the sequence of melting points from low to high, vacuumizing the smelting furnace, then filling protective gas, smelting, and stirring to obtain an alloy ingot;

step 2: turning over the alloy ingot obtained in the step 1, smelting again, and stirring to obtain a primary as-cast alloy;

and step 3: carrying out electroslag remelting and directional solidification on the primary as-cast alloy obtained in the step 2 to obtain a cast alloy;

the vacuum degree requirement of the step 1 is less than or equal to 1 x 10 during vacuum pumping^-3Filling protective gas after Pa;

the vacuum degree of the second smelting in the step 2 is required to be less than or equal to 1 x 10^-3Filling protective gas after Pa, wherein the protective gas is argon; the smelting temperature is 1450-1550 ℃;

in the step 3, the equipment used in the electroslag remelting directional solidification process is ESR-CDS500 electroslag remelting directional solidification equipment of Beijing Steel research high-tech technical component, Inc.;

the obtained alloy is in a casting state, the yield strength at room temperature is not lower than 500MPa, the tensile strength is not lower than 800MPa, and the elongation is between 30 and 50 percent.