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CN-121992273-A - Carbide-based eutectic medium-entropy alloy and preparation method thereof

CN121992273ACN 121992273 ACN121992273 ACN 121992273ACN-121992273-A

Abstract

The invention discloses a carbide-based eutectic entropy alloy and a preparation method thereof, wherein the chemical composition of the carbide-based eutectic entropy alloy is CrFeNi (NbC) x, wherein x is more than or equal to 0.1 and less than or equal to 0.3, the carbide-based eutectic entropy alloy is prepared by adopting a vacuum arc melting method, the solidification phase of the carbide-based eutectic alloy after vacuum arc melting is FCC, MC carbide and M 7 C 3 carbide, and when x=0.1, the solidification structure of the alloy is primary FCC+reticular eutectic FCC/MC+superfine eutectic FCC/M 7 C 3 . When x=0.2-0.3, the solidification structure of the alloy is primary MC+primary FCC+reticular eutectic FCC/MC+superfine eutectic FCC/M 7 C 3 , the Vickers hardness of the alloy is 235.6-287.0 HV, the yield strength of the alloy is 439-534 MPa, and the compressive strength (R pc30 ) of the alloy under a specified strain (30%) is 1482-1607 MPa.

Inventors

  • FENG YANAN
  • XUE YUNLONG
  • WU YUANTING
  • LIU HULIN
  • ZHANG XINMENG
  • HAI OU
  • YUAN LIANG

Assignees

  • 陕西科技大学

Dates

Publication Date
20260508
Application Date
20260112

Claims (10)

  1. 1. A carbide-based eutectic medium entropy alloy is characterized in that the chemical formula is CrFeNi (NbC) x , wherein x is more than or equal to 0.1 and less than or equal to 0.3.
  2. 2. A method of preparing the carbide-based eutectic medium entropy alloy according to claim 1, comprising the steps of: step 1, respectively placing pure metal elements Cr, fe, ni, nb into absolute ethyl alcohol, ultrasonically cleaning, and drying to obtain pretreated metal elements Cr, fe, ni, nb; Step 2, respectively weighing the pretreated pure metal simple substance Cr, fe, ni, nb and iron carbon particles according to a chemical general formula CrFeNi (NbC) x , wherein x is more than or equal to 0.1 and less than or equal to 0.3, and the carbon content in the iron carbon particles is 30 wt%; Step 3, sequentially placing the metal simple substance Cr, fe, ni, nb and the iron carbon particles weighed in the step 2 into a water-cooling crucible in a vacuum non-consumable arc melting furnace according to the sequence of the melting point from low to high, vacuumizing the vacuum non-consumable arc melting furnace until the melting point reaches 3×10 - 3 Pa, starting vacuum arc melting, and completely melting the raw materials to form an alloy ingot; And 4, turning over the cast ingot, remelting, repeatedly smelting for 5 times, and finally cooling to room temperature along with a furnace to obtain the carbide-based eutectic entropy alloy.
  3. 3. The method for preparing an entropy alloy in a carbide-based eutectic according to claim 2, wherein the purity of the elemental metals Cr, ni, nb in step 1 is 99.95%, and the purity of the iron carbon particles and elemental metal Fe is 99.9%.
  4. 4. The method for preparing the carbide-based eutectic medium entropy alloy according to claim 2, wherein the ultrasonic cleaning time in the step 1 is 15-20 min.
  5. 5. The method for preparing the entropy alloy in the carbide-based eutectic according to claim 2, wherein the process of vacuumizing the vacuum non-consumable arc melting furnace in the step 3 is that the vacuum degree in the vacuum non-consumable arc melting furnace is firstly vacuumized to 3×10 -3 ~6×10 -3 Pa, then argon is filled until the internal air pressure is 0.05 Pa, and the vacuum degree is vacuumized to 3×10 -3 after repeating for 3 times.
  6. 6. The method for producing an entropy alloy in a carbide-based eutectic according to claim 2, wherein elemental Ti for removing residual oxygen is placed in another water-cooled crucible in the vacuum non-consumable arc melting furnace in step 3.
  7. 7. The method for producing an entropy alloy in a carbide-based eutectic according to claim 2, wherein the vacuum arc melting in step 3 is performed under electromagnetic stirring.
  8. 8. A carbide-based eutectic mid-entropy alloy prepared by the method of any one of claims 2 to 7, wherein the solidification phase is FCC, MC carbide, and M 7 C 3 carbide, wherein MC is NbC carbide and M 7 C 3 is Cr-rich carbide.
  9. 9. The carbide-based eutectic mid-entropy alloy of claim 8, wherein the solidification structure of the alloy is primary fcc+, reticulated eutectic FCC/mc+ and ultrafine eutectic FCC/M 7 C 3 at x = 0.1; When x=0.2-0.3, the solidification structure of the alloy is primary MC+, primary FCC+, reticular eutectic FCC/MC+ and superfine eutectic FCC/M 7 C 3 .
  10. 10. The carbide-based eutectic medium entropy alloy according to claim 8, wherein the yield strength is 439 to 534 MPa, the compressive strength at 30% strain is 1482 to 1607 MPa, and the vickers hardness is 235.6 to 287 HV at room temperature.

Description

Carbide-based eutectic medium-entropy alloy and preparation method thereof Technical Field The invention belongs to the field of multi-principal element alloys, relates to a medium-entropy alloy and a preparation method thereof, and in particular relates to a carbide-based eutectic medium-entropy alloy and a preparation method thereof. Background In recent years, a multi-element novel alloy material has been attracting attention in the field of materials. The medium-entropy alloy has great application potential in the engineering field by virtue of high strength, high hardness, high wear resistance, high corrosion resistance and excellent high-temperature stability. However, the alloy still has obvious short plates, namely, the high strength and the high ductility are difficult to be compatible, the severe requirements of part of scenes on the comprehensive mechanical properties are difficult to meet, and secondly, the problems of poor melt fluidity, component segregation and the like easily occur in the smelting process because the alloy system contains a plurality of metal elements, so that the preparation difficulty of large-size cast ingots is extremely high, and the industrial application of the large-size cast ingots is seriously restricted. Yu et Al takes an Al 0.2 CoCrFeNi high-entropy alloy of single-phase FCC as a matrix, and WC, siC, tiC particles are added, so that the mechanical property and the wear resistance of the alloy are remarkably improved, wherein 15 vol percent of TiC composite material has optimal wear resistance. Gu et al used arc melting to prepare Fe 49.5Mn30Co10Cr10X0.5(X=B4 C, zrC and TiC) high entropy alloys, found that carbide ceramic particles could refine the matrix grains and stabilize the FCC phase, and the toughness of the alloy was effectively improved. However, the prior art scheme depends on the reinforcing performance of the added ceramic particles, and is not from the point of view of multi-eutectic structure design of the eutectic medium-entropy alloy, so that the core technical problem that the medium-entropy alloy is strong and plastic and easy to cast can not be fundamentally solved. Disclosure of Invention Aiming at the defects existing in the prior art, the invention aims to provide a carbide-based eutectic medium entropy alloy and a preparation method thereof, wherein the medium entropy alloy has good toughness matching and comprehensive mechanical properties. In order to achieve the above purpose, the invention is realized by adopting the following technical scheme: The chemical formula of the carbide-based eutectic entropy alloy is CrFeNi (NbC) x, wherein x is more than or equal to 0.1 and less than or equal to 0.3. The invention also provides a preparation method of the carbide-based eutectic medium entropy alloy, which comprises the following steps: step 1, respectively placing pure metal elements Cr, fe, ni, nb into absolute ethyl alcohol, ultrasonically cleaning, and drying to obtain pretreated metal elements Cr, fe, ni, nb; Step 2, respectively weighing the pretreated pure metal simple substance Cr, fe, ni, nb and iron carbon particles according to a chemical general formula CrFeNi (NbC) x, wherein x is more than or equal to 0.1 and less than or equal to 0.3, and the carbon content in the iron carbon particles is 30 wt%; Step 3, sequentially placing the metal simple substance Cr, fe, ni, nb and the iron carbon particles weighed in the step 2 into a water-cooling crucible in a vacuum non-consumable arc melting furnace according to the sequence of the melting point from low to high, vacuumizing the vacuum non-consumable arc melting furnace until the melting point reaches 3×10 - 3 Pa, starting vacuum arc melting, and completely melting the raw materials to form an alloy ingot; And 4, turning over the cast ingot, remelting, repeatedly smelting for 5 times, and finally cooling to room temperature along with a furnace to obtain the carbide-based eutectic entropy alloy. Preferably, the purity of the metal simple substances Cr, ni and Nb in the step1 is 99.95%, and the purity of the iron carbon particles and the metal simple substance Fe is 99.9%. Preferably, the ultrasonic cleaning time in the step 1 is 15-20 min. Preferably, the process of vacuumizing the vacuum non-consumable arc melting furnace in the step 3 comprises the steps of vacuumizing the vacuum non-consumable arc melting furnace to 3×10 -3~6×10-3 Pa, filling argon gas to the internal air pressure of 0.05 Pa, and vacuumizing to 3×10 -3~6×10-3 Pa after repeating for 3 times. Preferably, the elemental Ti for removing residual oxygen is placed in another water-cooled crucible in the vacuum non-consumable arc melting furnace described in step 3. Preferably, the vacuum arc melting described in step3 is performed under electromagnetic stirring. The invention also protects the carbide-based eutectic entropy alloy prepared by the method, wherein the solidified phase is FCC, MC carbide and M 7C3 carbide, whe