WO2020118802A1 - Lightweight high-entropy alloy having high strength and high plasticity and preparation method therefor - Google Patents

Abstract

A lightweight high-entropy alloy having high strength and high plasticity and a preparation method therefor, relating to the field of metal materials and preparation thereof. The high-entropy alloy is mainly composed of Ti, Zr, V, Nb, and M, the M being one or more of Al, Hf, Cr, Fe, Mg, Be, Li, Mo, Co, Ni, Si, B, O, and N. The method mainly regulates the content of each element to enable the alloy to have low density, high strength, and high plasticity, and have great application potential in the engineering field; moreover, the high-entropy alloy preparation method is simple to operate, and raw materials used are non-toxic and harmless, safe and reliable, and economical and practical.

Description

Lightweight high-entropy alloy with high strength and high plasticity and preparation method thereof Technical field

The invention relates to a lightweight high-entropy alloy with high strength and high plasticity and a preparation method thereof, belonging to the field of metal materials and preparation.

Background technique

A high-entropy alloy is an alloy composed of five or more components in approximately equal atomic ratios, and is also called a multi-primary high-disorder alloy. Due to multi-principal effects (high entropy effect, lattice distortion effect, hysteresis diffusion effect and cocktail effect), high-entropy alloys exhibit a different metallurgical physical mechanism than traditional alloys, and thus exhibit a series of excellent properties, such as outstanding High temperature strength, good low temperature plasticity, good wear resistance, good corrosion resistance and excellent radiation resistance. With the progress of research, the range of high-entropy alloys has been expanded, the components are no longer limited to five or more, the atomic ratio is gradually deviating from the equal atomic ratio, and the designability of the alloy is greatly improved.

At present, researchers generally adopt the method of adding a large amount of low-density metals in the first three cycles to reduce the density of high-entropy alloys, which results in a large number of second phases. Although low density, high hardness and high compressive strength can be obtained, the severe sacrifice of plasticity greatly limits its application in engineering.

Summary of the invention

In view of this, the present invention provides a lightweight high-entropy alloy with high strength and high plasticity and a preparation method thereof. The high-entropy alloy has low density, high strength and high plasticity, and has huge application potential in the engineering field And its preparation method is simple, safe, reliable, economical and practical.

The object of the present invention is achieved by the following technical solutions.

A lightweight high-entropy alloy with high strength and high plasticity, the high-entropy alloy is denoted as Ti _a Zr _b V _c Nb _d M _{x in} terms of atomic number ratio, M is Al, Hf, Cr, Fe, Mg, One or more of Be, Li, Mo, Co, Ni, Si, B, O, and N; where 25<a≤65, 0<b≤55, 0≤c<25, 0<d≤35, 0≤x<20, and a+b+c+d+x=100, c and x cannot be 0 at the same time.

Further, in Ti _a Zr _b V _c Nb _d M _x , 25<a≦60, 15≦b≦50, 0≦c<25, 5≦d≦30, 0≦x<20, and a+b+ c+d+x=100, c and x cannot be 0 at the same time.

Further, M is preferably one or more of Al, Hf, Cr, Fe, Mg, Be, Li, Mo, Co, and Ni.

The preparation method of the high-entropy alloy of the present invention includes the following steps:

Step 1: Put the clean elementary materials Ti, Zr, V, Nb and M into a melting furnace with a vacuum of less than or equal to 2.5×10 ^-3 Pa, and fill it with protective gas, and then smelt, the alloy liquid produced by smelting After cooling, an alloy ingot is obtained; the alloy ingot is turned over and repeated smelting more than three times to ensure a uniform composition and a high-entropy alloy ingot is obtained;

Step 2: Seal the high-entropy alloy ingot in a quartz tube filled with argon for solution treatment, the solution temperature is 900°C to 1200°C, and the holding time is 1h to 12h to obtain the high-entropy alloy.

Further, the purity of the elementary raw materials Ti, Zr, V, Nb, and M are greater than or equal to 99.7 wt%, respectively.

Further, the melting furnace is preferably an electric arc melting furnace.

Further, the shielding gas is preferably argon.

Beneficial effect:

(1) The high-entropy alloy of the present invention is composed of Ti, Zr, V, Nb, and M elements. Mainly by adjusting the content of each element, it has the performance advantages of low density, high strength and high plasticity. Huge application potential;

(2) The preparation method of the present invention is simple to operate, safe and reliable, and the raw materials used are non-toxic and harmless, and are easy to obtain.

BRIEF DESCRIPTION

FIG. 1 is a comparison diagram of X-ray diffractometer (XRD) patterns of the high-entropy alloys prepared in Examples 1 to 6.

2 is a metallographic diagram of the Ti ₆₀ Zr ₂₀ V ₃ Nb ₁₇ high-entropy alloy prepared in Example 1. FIG.

3 is a metallographic diagram of the Ti ₃₀ Zr ₂₇ V ₁₈ Nb ₂₅ high-entropy alloy prepared in Example 2. FIG.

4 is a metallographic diagram of the Ti ₅₀ Zr ₁₈ V ₁₂ Nb ₁₆ Al ₄ high-entropy alloy prepared in Example 3. FIG.

5 is a metallographic diagram of the Ti ₄₀ Zr ₂₃ V ₁₃ Nb ₁₉ Al ₅ high-entropy alloy prepared in Example 4. FIG.

6 is a metallographic diagram of the Ti ₃₀ Zr ₄₅ Nb ₇ Al ₈ Hf ₁₀ high-entropy alloy prepared in Example 5. FIG.

7 is a metallographic diagram of the Ti ₅₀ Zr ₂₅ V ₇ Nb ₁₂ Al ₅ Fe ₁ high-entropy alloy prepared in Example 6. FIG.

8 is a comparison diagram of quasi-static tensile engineering stress-strain curves of the high-entropy alloys prepared in Examples 1 to 6.

detailed description

The present invention will be further elaborated below with reference to the drawings and specific embodiments, wherein the methods are conventional methods unless otherwise specified, and the raw materials can be obtained from open commercial channels unless otherwise specified.

In the following embodiments:

High vacuum non-consumable arc melting furnace: DHL-400 high vacuum non-consumable arc melting furnace produced by Shenyang Scientific Instrument Co., Ltd., Chinese Academy of Sciences;

Phase analysis: The XRD spectrum of the high-entropy alloy prepared by Japan Rigaku Smartlab X-ray diffractometer was measured; among them, Cu target K _α ray, working voltage 40kV, working current 110mA, scanning angle range 20°～90° , Scanning speed 5°/min, step length 0.02°, measurement angle error is less than 0.01°; XRD test sample size is 10mm×10mm×5mm, first smooth the six surfaces with 240# sandpaper, and then irradiate the surface Grind with 400#, 600#, 800#, 1000#, 1200#, 1500#, 2000# sandpaper in sequence;

Microstructure: Observe the microstructure of the high-entropy alloy in solid solution state prepared by the German Zeiss Axio observer Alm research-grade metallurgical microscope; among them, the metallographic sample size is 10mm×10mm×5mm, which is first carried out by hot setting Mosaic, then use 400#, 600#, 800#, 1000#, 1200#, 1500#, 2000#, 3000#, 5000#, 7000# sandpaper, and then use silica suspension with a particle size of 0.02μm Polishing, finally using a corrosive agent with a volume ratio of HF:HNO ₃ :H ₂ O= ₁ : ₃ : _{20 to} soak for 5s-30s;

Density determination: According to the standard GB/T1423-1996, the density of the prepared high-entropy alloy is measured by the hydrostatic weighing method; the sample is weighed in the air first, and then the sample is placed on the spreader Weigh in water, and finally place the spreader in the water separately for weighing. Use the three weighing values to calculate the buoyancy of the sample in the water. Combine the density of the water to calculate the volume of the sample. The mass and the calculated volume can calculate the density of the alloy; where the sample used is the same as the XRD test sample;

Quasi-static tensile mechanical property test: According to the standard GB/T228.1-2010, the CMT4305 microcomputer electronic universal testing machine is used to perform the axial quasi-static tensile test at room temperature, the strain rate is selected as 10 ^-3 s ^-1 , and the test sample is Non-standard I-shaped parts, thickness 1.0mm, width 3.14mm, parallel section length 10mm, gauge length 5mm.

Example 1

The preparation steps of the light weight Ti ₆₀ Zr ₂₀ V ₃ Nb ₁₇ high-entropy alloy with high strength and high plasticity are as follows:

Step 1: Use elemental Ti, Zr, V and Nb with a purity of not less than 99.7wt% as raw materials, first remove the oxide scale on the surface of the above raw materials by grinding with a grinding wheel, and then perform ultrasonic vibration cleaning with absolute ethanol, and follow the atomic percentage Ti :Zr:V:Nb=60:20:3:17 Weigh out clean raw materials with a total mass of (70±0.01)g;

Step 2: Put the weighed raw materials into the water-cooled copper crucible of the high vacuum non-consumable arc melting furnace in order of melting point from low to high, and then evacuate until the vacuum degree in the melting furnace reaches 2.5×10 ^{After -3} Pa, it is filled with argon gas as protective gas; before smelting the alloy, the pure titanium metal ingot is first smelted to further reduce the oxygen content in the furnace cavity of the smelting furnace, and then alloying is smelted, and the alloy is homogenized by electromagnetic stirring during the smelting process. After the smelting alloy liquid is cooled, an alloy ingot is obtained; the alloy is turned over and the smelting is repeated 4 times to obtain a high-entropy alloy ingot;

Step 3: Seal the high-entropy alloy ingot in a quartz tube filled with argon gas for solution treatment at a solution temperature of 900°C and a holding time of 1 hour to obtain the Ti ₆₀ Zr ₂₀ V ₃ Nb ₁₇ high-entropy alloy.

It can be seen from the XRD spectrum in FIG. 1 that the prepared Ti ₆₀ Zr ₂₀ V ₃ Nb ₁₇ high-entropy alloy is mainly composed of the BCC phase. According to the metallographic photograph of FIG. 2, the Ti ₆₀ Zr ₂₀ V ₃ Nb ₁₇ high-entropy alloy prepared has an equiaxed grain structure. According to the test result of FIG. 8, the yield strength of the prepared Ti ₆₀ Zr ₂₀ V ₃ Nb ₁₇ high-entropy alloy is 758.06 MPa, and the elongation at break is 18.11%. After testing and calculation, it is known that the density of the prepared Ti ₆₀ Zr ₂₀ V ₃ Nb ₁₇ high-entropy alloy is 5.8356 g/cm ³ .

Example 2

The preparation steps of the light-weight Ti ₃₀ Zr ₂₇ V ₁₈ Nb ₂₅ high-entropy alloy with high strength and high plasticity are as follows:

Step 1: Use elemental Ti, Zr, V, and Nb with a purity of not less than 99.7wt% as raw materials, first use a grinding wheel to remove the scale on the surface of the above raw materials, and then use ultrasonic alcohol to perform ultrasonic vibration cleaning, and follow the atomic percentage Ti :Zr:V:Nb=30:27:18:25 Weigh out clean raw materials with a total mass of (70±0.01)g;

Step 2: Put the weighed raw materials into the water-cooled copper crucible of the high vacuum non-consumable arc melting furnace in order of melting point from low to high, and then evacuate until the vacuum degree in the melting furnace reaches 2.5×10 ^{After -3} Pa, it is filled with argon gas as protective gas; before smelting the alloy, the pure titanium metal ingot is first smelted to further reduce the oxygen content in the furnace cavity of the smelting furnace, and then alloying is smelted, and the alloy is homogenized by electromagnetic stirring during the smelting process. After the smelting alloy liquid is cooled, an alloy ingot is obtained; the alloy is turned over and the smelting is repeated 4 times to obtain a high-entropy alloy ingot;

Step 3: Seal the high-entropy alloy ingot in a quartz tube filled with argon gas for solution treatment at a solution temperature of 1200°C and a holding time of 1 hour to obtain the Ti ₃₀ Zr ₂₇ V ₁₈ Nb ₂₅ high-entropy alloy.

It can be seen from the XRD spectrum in FIG. 1 that the prepared Ti ₃₀ Zr ₂₇ V ₁₈ Nb ₂₅ high-entropy alloy is mainly composed of the BCC phase. According to the metallographic photograph of Fig. 3, the prepared Ti ₃₀ Zr ₂₇ V ₁₈ Nb ₂₅ high-entropy alloy has an equiaxed grain structure. According to the test results in FIG. 8, the yield strength of the prepared Ti ₃₀ Zr ₂₇ V ₁₈ Nb ₂₅ high-entropy alloy is 991.64 MPa, and the elongation at break is 12.95%. After testing and calculation, the density of the prepared Ti ₃₀ Zr ₂₇ V ₁₈ Nb ₂₅ high-entropy alloy is 6.0938 g/cm ³ .

Example 3

The preparation steps of the light-weight Ti ₅₀ Zr ₁₈ V ₁₂ Nb ₁₆ Al ₄ high-entropy alloy with high strength and high plasticity are as follows:

Step 1: Use elemental Ti, Zr, V, Nb, and Al with a purity of not less than 99.7wt% as raw materials, first use a grinding wheel to remove the scale on the surface of the above raw materials, and then use ultrasonic alcohol to perform ultrasonic vibration cleaning, and follow the atomic Percent Ti:Zr:V:Nb:Al=50:18:12:16:4 Weigh out the clean raw materials with a total mass of (70±0.01)g;

Step 2: Put the weighed raw materials into the water-cooled copper crucible of the high vacuum non-consumable arc melting furnace in order of melting point from low to high, and then evacuate until the vacuum degree in the melting furnace reaches 2.5×10 ^{After -3} Pa, it is filled with argon gas as protective gas; before smelting the alloy, the pure titanium metal ingot is first smelted to further reduce the oxygen content in the furnace cavity of the smelting furnace, and then alloying is smelted, and the alloy is homogenized by electromagnetic stirring during the smelting process. After the smelting alloy liquid is cooled, an alloy ingot is obtained; the alloy is turned over and the smelting is repeated 4 times to obtain a high-entropy alloy ingot;

Step 3: Seal the high-entropy alloy ingot in a quartz tube filled with argon gas for solution treatment at a solution temperature of 1000°C and a holding time of 3 hours to obtain the Ti ₅₀ Zr ₁₈ V ₁₂ Nb ₁₆ Al ₄ high-entropy alloy.

It can be seen from the XRD spectrum in FIG. 1 that the prepared Ti ₅₀ Zr ₁₈ V ₁₂ Nb ₁₆ Al ₄ high-entropy alloy is mainly composed of the BCC phase. According to the metallographic photograph of FIG. 4, the prepared Ti ₅₀ Zr ₁₈ V ₁₂ Nb ₁₆ Al ₄ high-entropy alloy has an equiaxed grain structure. According to the test results in FIG. 8, the yield strength of the prepared Ti ₅₀ Zr ₁₈ V ₁₂ Nb ₁₆ Al ₄ high-entropy alloy is 795.2 MPa, and the elongation at break is 36.57%. After testing and calculation, it is known that the density of the prepared Ti ₅₀ Zr ₁₈ V ₁₂ Nb ₁₆ Al ₄ high-entropy alloy is 5.6072 g/cm ³ .

Example 4

The preparation steps of the high-entropy alloy with high strength and high plasticity, light weight Ti ₄₀ Zr ₂₃ V ₁₃ Nb ₁₉ Al ₅ are as follows:

Step 1: Use elemental Ti, Zr, V, Nb, and Al with a purity of not less than 99.7wt% as raw materials, first use a grinding wheel to remove the scale on the surface of the above raw materials, and then use ultrasonic alcohol to perform ultrasonic vibration cleaning, and follow the atomic The percentage Ti:Zr:V:Nb:Al=40:23:13:19:5 weighs out the clean raw materials with a total mass of (70±0.01)g;

Step 2: Put the weighed raw materials into the water-cooled copper crucible of the high vacuum non-consumable arc melting furnace in order of melting point from low to high, and then evacuate until the vacuum degree in the melting furnace reaches 2.5×10 ^{After -3} Pa, it is filled with argon gas as protective gas; before smelting the alloy, the pure titanium metal ingot is first smelted to further reduce the oxygen content in the furnace cavity of the smelting furnace, and then alloying is smelted, and the alloy is homogenized by electromagnetic stirring during the smelting process. After the smelting alloy liquid is cooled, an alloy ingot is obtained; the alloy is turned over and the smelting is repeated 4 times to obtain a high-entropy alloy ingot;

Step 3: Seal the high-entropy alloy ingot in a quartz tube filled with argon gas for solution treatment at a solution temperature of 1100°C and a holding time of 3 hours to obtain the Ti ₄₀ Zr ₂₃ V ₁₃ Nb ₁₉ Al ₅ high-entropy alloy.

It can be seen from the XRD spectrum in FIG. 1 that the prepared Ti ₄₀ Zr ₂₃ V ₁₃ Nb ₁₉ Al ₅ high-entropy alloy is mainly composed of the BCC phase. According to the metallographic photograph of FIG. 5, the prepared Ti ₄₀ Zr ₂₃ V ₁₃ Nb ₁₉ Al ₅ high-entropy alloy has an equiaxed grain structure. According to the test results in FIG. 8, the yield strength of the prepared Ti ₄₀ Zr ₂₃ V ₁₃ Nb ₁₉ Al ₅ high-entropy alloy is 1077.3 MPa, and the elongation at break is 25.84%. After testing and calculation, the density of the prepared Ti ₄₀ Zr ₂₃ V ₁₃ Nb ₁₉ Al ₅ high-entropy alloy is 5.9201 g/cm ³ .

Example 5

The preparation steps of the light-weight Ti ₃₀ Zr ₄₅ Nb ₇ Al ₈ Hf ₁₀ high-entropy alloy with high strength and high plasticity are as follows:

Step 1: Use elemental Ti, Zr, Nb, Al, and Hf with a purity of not less than 99.7wt% as raw materials, first use a grinding wheel to remove the oxide scale on the surface of the above raw materials, and then use ultrasonic alcohol to perform ultrasonic vibration cleaning, and follow the atomic Percentage Ti:Zr:Nb:Al:Hf=30:45:7:8:10 Weigh out clean raw materials with a total mass of (70±0.01)g;

Step 2: Put the weighed raw materials into the water-cooled copper crucible of the high vacuum non-consumable arc melting furnace in order of melting point from low to high, and then evacuate until the vacuum degree in the melting furnace reaches 2.5×10 ^{After -3} Pa, it is filled with argon gas as protective gas; before smelting the alloy, the pure titanium metal ingot is first smelted to further reduce the oxygen content in the furnace cavity of the smelting furnace, and then alloying is smelted, and the alloy is homogenized by electromagnetic stirring during the smelting process. After the smelting alloy liquid is cooled, an alloy ingot is obtained; the alloy is turned over and the smelting is repeated 4 times to obtain a high-entropy alloy ingot;

Step 3: Seal the high-entropy alloy ingot in a quartz tube filled with argon for solution treatment at a solution temperature of 1200°C and a holding time of 12 hours to obtain the Ti ₃₀ Zr ₄₅ Nb ₇ Al ₈ Hf ₁₀ high-entropy alloy.

It can be seen from the XRD spectrum in FIG. 1 that the prepared Ti ₃₀ Zr ₄₅ Nb ₇ Al ₈ Hf ₁₀ high-entropy alloy is mainly composed of the BCC phase. According to the metallographic photograph of FIG. 6, the prepared Ti ₃₀ Zr ₄₅ Nb ₇ Al ₈ Hf ₁₀ high-entropy alloy has an equiaxed grain structure. According to the test results of FIG. 8, the yield strength of the prepared Ti ₃₀ Zr ₄₅ Nb ₇ Al ₈ Hf ₁₀ high-entropy alloy is 710.59 MPa, and the elongation at break is 12.35%. After testing and calculation, it is known that the density of the prepared Ti ₃₀ Zr ₄₅ Nb ₇ Al ₈ Hf ₁₀ high-entropy alloy is 6.4338 g/cm ³ .

Example 6

The preparation steps of the high-entropy alloy with high strength and plasticity and light weight Ti ₅₀ Zr ₂₅ V ₇ Nb ₁₂ Al ₅ Fe ₁ are as follows:

Step 1: Use elemental Ti, Zr, V, Nb, Al, and Fe with a purity of not less than 99.7wt% as raw materials, first use a grinding wheel to remove the scale on the surface of the above raw materials, and then use ultrasonic alcohol to perform ultrasonic vibration cleaning, and According to the atomic percentage Ti:Zr:V:Nb:Al:Fe=50:25:7:12:5:1, the clean raw material with a total mass of (70±0.01) g is weighed out;

Step 2: Put the weighed raw materials into the water-cooled copper crucible of the high vacuum non-consumable arc melting furnace in order of melting point from low to high, and then evacuate until the vacuum degree in the melting furnace reaches 2.5×10 ^{After -3} Pa, it is filled with argon gas as protective gas; before smelting the alloy, the pure titanium metal ingot is first smelted to further reduce the oxygen content in the furnace cavity of the smelting furnace, and then alloying is smelted, and the alloy is homogenized by electromagnetic stirring during the smelting process. After the smelting alloy liquid is cooled, an alloy ingot is obtained; the alloy is turned over and the smelting is repeated 4 times to obtain a high-entropy alloy ingot;

Step 3: Seal the high-entropy alloy ingot in a quartz tube filled with argon for solution treatment at a solution temperature of 1000°C and a holding time of 12 hours to obtain the Ti ₅₀ Zr ₂₅ V ₇ Nb ₁₂ Al ₅ Fe ₁ high-entropy alloy.

It can be seen from the XRD spectrum in FIG. 1 that the prepared Ti ₅₀ Zr ₂₅ V ₇ Nb ₁₂ Al ₅ Fe ₁ high-entropy alloy is mainly composed of the BCC phase. According to the metallographic photograph of FIG. 7, the prepared Ti ₅₀ Zr ₂₅ V ₇ Nb ₁₂ Al ₅ Fe ₁ high-entropy alloy has an equiaxed grain structure. According to the test results in FIG. 8, the yield strength of the prepared Ti ₅₀ Zr ₂₅ V ₇ Nb ₁₂ Al ₅ Fe ₁ high-entropy alloy is 995.49 MPa, and the elongation at break is 9.45%. After testing and calculation, it is known that the density of the prepared Ti ₅₀ Zr ₂₅ V ₇ Nb ₁₂ Al ₅ Fe ₁ high-entropy alloy is 5.5533 g/cm ³ .

In summary, the above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (7)

1. A lightweight high-entropy alloy with high strength and high plasticity, characterized in that the high-entropy alloy is recorded as Ti _a Zr _b V _c Nb _d M _x according to the atomic number ratio, M is Al, Hf, Cr, More than one of Fe, Mg, Be, Li, Mo, Co, Ni, Si, B, O and N;

   Among them, 25<a≤65, 0<b≤55, 0≤c<25, 0<d≤35, 0≤x<20, and a+b+c+d+x=100, c and x cannot be simultaneously Is 0.
2. The light-weight high-entropy alloy with high strength and high plasticity according to claim 1, wherein in Ti _a Zr _b V _c Nb _d M _x , 25<a≤60, 15≤b≤50, 0 ≤c<25, 5≤d≤30, 0≤x<20, and a+b+c+d+x=100, c and x cannot be 0 at the same time.
3. The light-weight high-entropy alloy with high strength and high plasticity according to claim 2, wherein M is one of Al, Hf, Cr, Fe, Mg, Be, Li, Mo, Co and Ni the above.
4. A method for preparing a lightweight and high-entropy alloy with high strength and high plasticity according to any one of claims 1 to 3, wherein the method steps are as follows,

   Step 1: Put the clean elementary materials Ti, Zr, V, Nb and M into a melting furnace with a vacuum of less than or equal to 2.5×10 ^-3 Pa, and fill it with protective gas, and then smelt, the alloy liquid produced by smelting After cooling, an alloy ingot is obtained; the alloy ingot is turned over and repeated smelting more than three times to obtain a high-entropy alloy ingot;

   Step 2: Seal the high-entropy alloy ingot in a quartz tube filled with argon for solution treatment, the solution temperature is 900°C to 1200°C, and the holding time is 1h to 12h to obtain the high-entropy alloy.
5. The method for preparing a lightweight and high-entropy alloy with high strength and high plasticity according to claim 4, wherein the purity of the elementary raw materials Ti, Zr, V, Nb and M is greater than or equal to 99.7 wt%, respectively.
6. The method for preparing a light-weight high-entropy alloy with high strength and high plasticity according to claim 4, characterized in that an arc melting furnace is used for melting.
7. The method for preparing a light and high-entropy alloy with high strength and high plasticity according to claim 4, wherein the protective gas is argon.

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