Soft magnetic multi-principal-element alloy with excellent mechanical property and corrosion resistance as well as preparation method and application of soft magnetic multi-principal-element alloy

Abstract

The invention provides a soft magnetic multi-principal-element alloy with excellent mechanical property and corrosion resistance as well as a preparation method and application of the soft magnetic multi-principal-element alloy. The general formula of the soft magnetic multi-principal-element alloy with the excellent mechanical property and corrosion resistance is FeaCobCrcSidVeMofCug, wherein 45% < = a < = 70%, 0% < = b < = 15%, 12% < = c < = 25%, 2% < = d < = 8%, 0% < = e < = 5%, 0% < = f < = 2%, 0% < = g < = 3%, a + b + c + d + e + f + g = 100%, and a, b, c, d, e, f and g are molar percentages of corresponding elements respectively. The invention further discloses a preparation method of the soft magnetic multi-principal-element alloy with excellent mechanical property and corrosion resistance. The soft magnetic multi-principal-element alloy with excellent mechanical property and corrosion resistance has excellent strong plasticity, corrosion resistance and soft magnetic property.

Description

Technical Field

[0001] The present invention relates to alloy technology, and in particular to a soft magnetic multi-principal element alloy with excellent mechanical properties and corrosion resistance, and a preparation method and use thereof. Background Art

[0002] The extreme environment of the marine environment, such as high humidity, high salinity, complex and variable temperature, marine fluid scouring, wear, fatigue, electrochemical corrosion and biological corrosion, has put forward higher requirements on material performance. Soft magnetic materials mainly play a magnetic conductivity role in power electronic systems to achieve efficient conversion between electrical energy, magnetic energy and mechanical energy. Existing soft magnetic materials such as Fe-Si, Fe-Ni, Fe-Co and other alloys have insufficient corrosion resistance and mechanical properties and cannot meet the application in extreme marine environments. Since the antiferromagnetism of the corrosion-resistant element Cr and the non-magnetic strengthening elements will seriously deteriorate the saturation magnetization strength of the magnetic material, the concentration of these elements needs to be strictly controlled in traditional soft magnetic alloys, so that their corrosion performance cannot meet the use in highly corrosive marine environments; in addition, the addition of these elements will also cause phase separation in the alloy, hindering the movement of the magnetic domain wall of the soft magnetic material during magnetization and demagnetization, resulting in a sharp increase in the coercive force of the material.

[0003] Therefore, there is an urgent need to design a soft magnetic alloy that has both excellent mechanical properties and corrosion resistance to meet the application of soft magnetic materials in extremely complex marine environments. Summary of the invention

[0004] The purpose of the present invention is to propose a soft magnetic multi-principal component alloy with excellent mechanical properties and corrosion resistance, in order to address the contradiction between corrosion properties, mechanical properties and soft magnetic properties in traditional soft magnetic alloys. The soft magnetic multi-principal component alloy has excellent strong plasticity, corrosion resistance and soft magnetic properties.

[0005] It should be noted that, in the present invention, unless otherwise specified, the specific meaning of "including" in relation to composition limitations and descriptions includes both open-ended "including", "comprising", etc. and similar meanings, as well as closed-ended "composed of", "composed of", etc. and similar meanings.

[0006] To achieve the above object, the technical solution adopted by the present invention is: a soft magnetic multi-principal alloy with excellent mechanical properties and corrosion resistance, the general formula is Fe a Co b Cr c Si d V e Mo f Cu g, where 45%≤a≤70%, 0%≤b≤15%, 12%≤c≤25%, 2%≤d≤8%, 0%≤e≤5%, 0%≤f≤2%, 0%≤g≤3%, and a+b+c+d+e+f+g=100%, a, b, c, d, e, f and g are the molar percentages of the corresponding elements respectively.

[0007] Furthermore, the general formula of the soft magnetic multi-principal alloy having both excellent mechanical properties and corrosion resistance is Fe a Co b Cr c Si d V e Mo f Cu g Satisfies: 50.2%≤a≤70%, 0%<b≤10.8%, 15.5%≤c≤24.6%, 2.5%≤d≤7.6%, 0%<e≤4.5%, 0.5%≤f≤2% and 0%<g≤2.5%.

[0008] Furthermore, the soft magnetic multi-principal element alloy having both excellent mechanical properties and corrosion resistance has a saturation magnetization of 120emu / g to 170emu / g and a coercive force of 10A / m to 300A / m.

[0009] Furthermore, the soft magnetic multi-principal element alloy having both excellent mechanical properties and corrosion resistance has a room temperature tensile yield strength of 400MPa to 850MPa, a tensile strength of 500MPa to 900MPa, and an elongation after fracture of 8% to 30%.

[0010] Furthermore, the corrosion performance of the soft magnetic multi-principal alloy having both excellent mechanical properties and corrosion resistance in a 3.5wt.% NaCl aqueous solution is comparable to that of 316L stainless steel.

[0011] Another object of the present invention is to disclose a method for preparing a soft magnetic multi-principal alloy having both excellent mechanical properties and corrosion resistance, comprising the following steps:

[0012] Step 1, weigh the raw materials according to the molar percentage of each component in the general formula: Fe, Co, Cr, Si, V, Mo and Cu;

[0013] Step 2: Place the raw materials into a melting chamber of a non-consumable vacuum arc furnace or an electromagnetic induction melting furnace for melting, and cool naturally to obtain a Fe-Co-Cr-Si-V-Mo-Cu soft magnetic multi-principal alloy ingot;

[0014] Step three, the Fe-Co-Cr-Si-V-Mo-Cu soft magnetic multi-principal alloy ingot is subjected to hot rolling deformation treatment; then the sample is subjected to high-temperature solution treatment at 1000℃~1200℃ for 10~60min, and water quenching is performed to obtain the Fe-Co-Cr-Si-V-Mo-Cu soft magnetic multi-principal alloy with excellent mechanical properties and corrosion resistance.

[0015] Furthermore, the purity of the Fe, Co, Cr, Si, V, Mo and Cu raw materials is above 99wt.%.

[0016] Furthermore, in step 2, when a non-consumable vacuum arc furnace is used for melting, Fe, Co, Cr, Si, V and Cu raw materials are sequentially placed in the melting chamber of the vacuum arc furnace, and the Mo element with the highest melting point is placed at the top. That is, when arc melting is used, the Mo element with a high melting point needs to be placed at the top; when induction melting is used, it is placed in the middle of the crucible.

[0017] Furthermore, before preparing the alloy ingot, the vacuum degree of the arc furnace melting chamber needs to be pumped to 3.5×10 -3 ~5×10 -3 Pa, fill with high-purity argon gas to make the vacuum degree reach 0.05~0.04Mpa.

[0018] Furthermore, the elemental Ti needs to be smelted before smelting to allow it to fully react with the remaining O2.

[0019] Furthermore, when preparing the alloy ingot, the alloy melting current is 350-600A, the melting time is 2-5min, the sample is turned over after solidification and cooling, and the above operation is repeated 5-8 times. Preferably, the alloy melting current is 400-550A, the melting time is 2-3min, the sample is turned over after solidification and cooling, and the above operation is repeated 6-8 times.

[0020] Furthermore, the rolling temperature of the hot rolling deformation treatment is 900-1200° C., and the deformation amount is 50%-90%.

[0021] Furthermore, before hot rolling, the alloy ingot needs to be kept at the rolling temperature for 20 to 60 minutes depending on the sample size. After hot rolling, the sample is naturally cooled in the air, and the sample subjected to subsequent solution heat treatment is water-cooled.

[0022] Another object of the present invention is to disclose a use of a soft magnetic multi-principal element alloy having both excellent mechanical properties and corrosion resistance in the electromagnetic field.

[0023] Furthermore, the soft magnetic multi-principal alloy having both excellent mechanical properties and corrosion resistance is particularly suitable for the fields of drive motors, electronic devices and wind power generation metal parts in high load and corrosive environments.

[0024] Furthermore, the soft magnetic multi-principal alloy having both excellent mechanical properties and corrosion resistance is particularly suitable for the fields of drive motors, electronic devices and wind power generation metal parts in marine environments.

[0025] The soft magnetic multi-principal alloy of the present invention has both excellent mechanical properties and corrosion resistance, and its composition is scientific and reasonable, and its preparation method is simple and easy to implement. Compared with the prior art, it has the following advantages:

[0026] 1) The soft magnetic multi-principal alloy with excellent mechanical properties and corrosion resistance of the present invention contains specific element selection and reasonable ratio, among which high concentrations of Fe and Co elements ensure the saturation magnetization intensity of the alloy; a large amount of Cr elements form a dense oxide film, giving the alloy excellent corrosion resistance; Mo elements improve the material's pitting resistance, Si elements improve corrosion resistance and produce excellent strengthening effects at the same time, and the negative mixing enthalpy of V and Cu elements with Fe and Co elements drives the change of the local chemical composition of the material, thereby improving the mechanical properties of the material.

[0027] 2) The soft magnetic multi-principal alloy of the present invention having both excellent mechanical properties and corrosion resistance exhibits excellent room temperature tensile properties after simple thermomechanical treatment, with a yield strength of up to 780 MPa, a tensile strength of up to 792 MPa, and an elongation at break of up to 17.5%.

[0028] 3) The saturation magnetization intensity (Ms) of the Fe-Co-Cr-Si-V-Mo-Cu soft magnetic multi-principal alloy of the present invention, which has both excellent mechanical properties and corrosion resistance, exceeds 130emu / g, and the coercive force (Hc) is less than 2.29Oe, and has excellent soft magnetic properties.

[0029] 4) The raw materials of the Fe-Co-Cr-Si-V-Mo-Cu soft magnetic multi-principal alloy of the present invention are easy to obtain, the preparation process is simple and easy, and the excellent corrosion resistance, soft magnetic properties and mechanical properties are combined, so that the alloy has broad application prospects in the soft magnetic field under extremely complex environmental conditions in the ocean. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The Fe alloy prepared in Example 1 of the present invention has excellent mechanical properties and corrosion resistance. 56.8 Co 10 Cr 22 Si5V3Mo 1.2 Room temperature tensile engineering stress-strain curves of Cu2 soft magnetic multi-principal alloys;

[0031] Figure 2 The Fe alloy prepared in Example 1 of the present invention has excellent mechanical properties and corrosion resistance. 56.8 Co 10 Cr 22 Si5V3Mo1.2 Room temperature hysteresis loop of Cu2 soft magnetic multi-principal alloy (left) and a local enlarged view of the central area (right);

[0032] Figure 3 The Fe alloy prepared in Example 1 of the present invention has excellent mechanical properties and corrosion resistance. 56.8 Co 10 Cr 22 Si5V3Mo 1.2 Potentiodynamic polarization curves of electrochemical corrosion test of Cu2 soft magnetic multi-principal alloy and 316L stainless steel in 3.5wt.% NaCl solution;

[0033] Figure 4 The Fe alloy prepared in Example 1 of the present invention has excellent mechanical properties and corrosion resistance. 56.8 Co 10 Cr 22 Si5V3Mo 1.2 XRD diffraction pattern of Cu2 soft magnetic multi-principal alloy;

[0034] Figure 5 The Fe alloy prepared in Example 1 of the present invention has excellent mechanical properties and corrosion resistance. 56.8 Co 10 Cr 22 Si5V3Mo 1.2 SEM microstructure morphology of Cu2 soft magnetic multi-principal alloy;

[0035] Figure 6 The Fe alloy prepared in Example 2 of the present invention has excellent mechanical properties and corrosion resistance. 57.8 Co 10 Cr 22 Si5V3Mo 1.2 Room temperature tensile engineering stress-strain curves of Cu1 soft magnetic multi-principal alloy;

[0036] Figure 7 The Fe alloy prepared in Example 2 of the present invention has excellent mechanical properties and corrosion resistance. 57.8 Co 10 Cr 22 Si5V3Mo 1.2 The hysteresis loop of Cu1 soft magnetic multi-principal alloy (left) and the enlarged view of the central area (right);

[0037] Figure 8 The Fe alloy prepared in Example 2 of the present invention has excellent mechanical properties and corrosion resistance. 57.8 Co 10 Cr 22 Si5V3Mo 1.2Potentiodynamic polarization curve of Cu1 soft magnetic multi-principal alloy in electrochemical corrosion test in 3.5wt.% NaCl solution;

[0038] Fig. 9 The Fe alloy prepared in Example 2 of the present invention has excellent mechanical properties and corrosion resistance. 57.8 Co 10 Cr 22 Si5V3Mo 1.2 XRD diffraction pattern of Cu1 soft magnetic multi-principal alloy;

[0039] Fig.10 The Fe alloy prepared in Example 2 of the present invention has excellent mechanical properties and corrosion resistance. 57.8 Co 10 Cr 22 Si5V3Mo 1.2 SEM microstructure of Cu1 soft magnetic multi-principal alloy. DETAILED DESCRIPTION

[0040] The present invention is further described below with reference to the examples. The description of the technical features described below is based on representative embodiments and specific examples of the present invention, but the present invention is not limited to these embodiments and specific examples. It should be noted that:

[0041] Unless otherwise stated, the units used in this specification are all international standard units, and the numerical values ​​and numerical ranges appearing in the present invention should be understood to include the inevitable systematic errors in industrial production.

[0042] In this specification, the numerical range expressed using "a numerical value A to a numerical value B" means a range including the endpoints A and B.

[0043] In this specification, the numerical range expressed using "above" or "below" means a numerical range including the number.

[0044] In this specification, the word "may" means both performing a certain process and not performing a certain process.

[0045] In this specification, the use of "optional" or "optional" indicates that certain substances, components, execution steps, application conditions and other factors are used or not used.

[0046] In this specification, when "normal temperature" or "room temperature" is used, the temperature may be 15-25°C.

[0047] In this manual, the reagents or instruments used without indicating the manufacturer are all conventional products that can be obtained through commercial purchase.

[0048] Example 1

[0049] This embodiment discloses a Fe-Co-Cr-Si-V-Mo-Cu soft magnetic multi-principal alloy having both excellent mechanical properties and corrosion resistance, and its general formula is Fe 56.8 Co 10 Cr 22 Si5V3Mo 1.2 Cu2.

[0050] In this embodiment, a preparation method of a Fe-Co-Cr-Si-V-Mo-Cu soft magnetic multi-principal alloy having both excellent mechanical properties and corrosion resistance is as follows:

[0051] Step 1: weigh industrial-grade pure single-element raw materials such as Fe, Co, Cr, Si, V, Mo and Cu according to the general formula components.

[0052] Step 2: Put the weighed raw materials into the vacuum arc melting furnace, with the high melting point Mo element at the top, melt and close the melting chamber, and pump the vacuum degree of the melting chamber to 3×10 -3 Pa, backfill with high-purity argon to 0.05MPa, first smelt the single Ti ingot for 80s to remove residual O2, then smelt the Fe-Co-Cr-Si-V-Mo-Cu alloy raw material at 500A for 3min, turn the sample over and repeat the operation 7 times to obtain the target alloy ingot.

[0053] Step 3: The obtained alloy ingot is rolled at 1100°C and then air-cooled, with a deformation of 90%. The rolled alloy is kept at 1200°C for 20 minutes and then water-cooled to obtain Fe alloy with excellent mechanical properties and corrosion resistance. 56.8 Co 10 Cr 22 Si5V3Mo 1.2 Cu2 soft magnetic multi-principal alloy.

[0054] Figure 1 The Fe alloy prepared in Example 1 has excellent mechanical properties and corrosion resistance. 56.8 Co 10 Cr 22 Si5V3Mo 1.2 The room temperature tensile engineering stress-strain curve of the Cu2 soft magnetic multi-principal alloy shows that its yield strength is 780MPa, its tensile strength is 792MPa, and its elongation at break is 17.5%. Figure 2 The Fe alloy prepared in Example 1 has excellent mechanical properties and corrosion resistance. 56.8 Co 10 Cr 22 Si5V3Mo 1.2 The hysteresis loop and the local enlarged image of the central area of ​​the Cu2 soft magnetic multi-principal element alloy, its saturation magnetization intensity (Ms) is 131.7emu / g, and the coercive force (Hc) is 2.29Oe. Figure 3 The Fe alloy prepared in Example 1 has excellent mechanical properties and corrosion resistance. 56.8 Co 10 Cr 22 Si5V3Mo 1.2 The potentiodynamic polarization curve of the Cu2 soft magnetic multi-principal alloy in the electrochemical corrosion test in 3.5wt.% NaCl solution shows that compared with the traditional 316L stainless steel, the alloy has a higher pitting potential and a wider passivation range. This shows that the alloy has excellent mechanical properties, corrosion resistance and soft magnetic properties, which can meet the use of soft magnetic materials in extreme marine environments. Figure 4 This is the XRD diffraction analysis spectrum of the soft magnetic multi-principal component alloy prepared in Example 1. The multi-principal component alloy exhibits a diffraction peak of a single BCC structure. Figure 5 This is a SEM microstructure image of the soft magnetic multi-principal component alloy prepared in Example 1, which shows that the alloy presents a single-phase equiaxed crystal structure.

[0055] Example 2

[0056] This embodiment discloses a Fe-Co-Cr-Si-V-Mo-Cu soft magnetic multi-principal alloy having both excellent mechanical properties and corrosion resistance, and its general formula is Fe 57.8 Co 10 Cr 22 Si5V3Mo 1.2 Cu1.

[0057] The preparation method of the Fe-Co-Cr-Si-V-Mo-Cu soft magnetic multi-principal alloy with excellent mechanical properties and corrosion resistance described in this embodiment is the same as that in Example 1.

[0058] Figure 6 The Fe prepared in Example 2 57.8 Co 10 Cr 22 Si5V3Mo 1.2 The room temperature tensile engineering stress-strain curve of the Cu1 soft magnetic multi-principal alloy shows that the yield strength, tensile strength and elongation at break are 653MPa, 696MPa and 28% respectively. Figure 7 The Fe prepared in Example 2 57.8 Co 10 Cr 22 Si5V3Mo 1.2 The hysteresis loop and the local enlarged image of the central area of ​​the Cu1 soft magnetic multi-principal element alloy, its saturation magnetization intensity (Ms) and coercive force (Hc) are 134.72mu / g and 2.015Oe respectively. Figure 8 The Fe prepared in Example 2 57.8 Co 10 Cr 22 Si5V3Mo1.2 The potentiodynamic polarization curve of the Cu1 soft magnetic multi-principal alloy in the electrochemical corrosion test in 3.5wt.% NaCl solution shows excellent corrosion resistance. Fig. 9 The figure shows the Fe prepared in Example 2. 57.8 Co 10 Cr 22 Si5V3Mo 1.2 XRD diffraction pattern and SEM microstructure of Cu1 soft magnetic multi-principal alloy. The diffraction pattern shows that the alloy is composed of BCC phase. Combined with the SEM image, the alloy presents a single BCC equiaxed crystal structure.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A soft magnetic multi-principal alloy having both excellent mechanical properties and corrosion resistance, characterized in that: The general formula is Fe a Co b Cr c Si d V e Mo f Cu g , where 45%≤a≤70%, 0%≤b≤15%, 12%≤c≤25%, 2%≤d≤8%, 0%≤e≤5%, 0%≤f≤2%, 0%≤g≤3%, and a+b+c+d+e+f+g=100%, a, b, c, d, e, f and g are the molar percentages of the corresponding elements respectively.

2. A method for preparing the soft magnetic multi-principal alloy having excellent mechanical properties and corrosion resistance as claimed in claim 1, characterized in that: The following steps are involved: Step 1, weigh the raw materials according to the molar percentage of each component in the general formula: Fe, Co, Cr, Si, V, Mo and Cu; Step 2: placing the raw materials into a melting chamber of a non-consumable vacuum arc furnace or an electromagnetic induction melting furnace for melting, and naturally cooling to obtain a Fe-Co-Cr-Si-V-Mo-Cu soft magnetic multi-principal alloy ingot; Step three, the Fe-Co-Cr-Si-V-Mo-Cu soft magnetic multi-principal alloy ingot is subjected to hot rolling deformation treatment; then the sample is subjected to high-temperature solution treatment at 1000℃~1200℃ for 10~60min, and water-cooled to obtain a soft magnetic multi-principal alloy with excellent mechanical properties and corrosion resistance.

3. The method for preparing the soft magnetic multi-principal alloy having excellent mechanical properties and corrosion resistance according to claim 2, characterized in that: The purity of the raw materials of Fe, Co, Cr, Si, V, Mo and Cu is all above 99wt.%.

4. The method for preparing the soft magnetic multi-principal alloy having excellent mechanical properties and corrosion resistance according to claim 2, characterized in that: Step 2: When a non-consumable vacuum arc furnace is used for smelting, Fe, Co, Cr, Si, V and Cu raw materials are sequentially placed in the melting chamber of the vacuum arc furnace, and the Mo element with the highest melting point is placed on the top.

5. The method for preparing the soft magnetic multi-principal alloy having excellent mechanical properties and corrosion resistance according to claim 2, characterized in that: Before preparing alloy ingots, the vacuum degree of the arc furnace melting chamber needs to be pumped to 3.5×10 -3 ~5×10 -3 Pa, fill with high-purity argon gas to make the vacuum degree reach 0.05~0.04Mpa.

6. The method for preparing the soft magnetic multi-principal alloy having excellent mechanical properties and corrosion resistance according to claim 2, characterized in that: Before smelting, the elemental Ti needs to be smelted to allow it to fully react with the remaining O2.

7. The method for preparing the soft magnetic multi-principal alloy having excellent mechanical properties and corrosion resistance according to claim 2, characterized in that: When preparing alloy ingots, the alloy melting current is 350-600A, the melting time is 2-5min, and the sample is turned over after solidification and cooling, and the above operation is repeated 5-8 times.

8. The method for preparing the soft magnetic multi-principal alloy having both excellent mechanical properties and corrosion resistance according to claim 2, characterized in that: The rolling temperature of the hot rolling deformation treatment is 900-1200° C., and the deformation amount is 50%-90%.

9. The method for preparing the soft magnetic multi-principal alloy having excellent mechanical properties and corrosion resistance according to claim 2, characterized in that: Before hot rolling, the alloy ingot needs to be kept at the rolling temperature for 20 to 60 minutes according to the sample size. After hot rolling, the sample is naturally cooled in the air. After the recrystallization recovery heat treatment, the sample is water quenched.

10. Use of the soft magnetic multi-principal component alloy having excellent mechanical properties and corrosion resistance as claimed in claim 1 or 2 in the electromagnetic field.

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