Reinforced molybdenum alloy wire and preparation method thereof

Abstract

The invention provides a reinforced molybdenum alloy wire and a preparation method thereof. The alloy wire comprises the following components in percentage by weight: 2-22 wt% of Re, 0.5-50 wt% of W, 0.1-1.0 wt% of La and the balance of Mo. The molybdenum alloy wire with rhenium and tungsten as alloy strengthening elements and rare earth lanthanum oxide as a second strengthening phase is prepared by combining powder metallurgy with a hot drawing process, and the alloy composition proportion, the powder metallurgy process and the drawing hot processing process are optimized. The reinforced molybdenum alloy wire prepared by the method has relatively high room-temperature and high-temperature strength, relatively low elastic modulus and good winding and bending performance, and is suitable for alloy wires for high-temperature springs.

Description

Technical Field

[0001] The invention belongs to the technical field of metal materials and manufacturing, and particularly relates to a reinforced molybdenum alloy wire and a preparation method thereof. Background Art

[0002] Alloy wire for high temperature springs should have technical characteristics such as good winding performance, excellent room temperature and high temperature strength, and good resistance to high temperature creep. Alloy wire for high temperature springs is generally based on high temperature alloys, such as GH4145, GH4169, and GH2132, which are often used for springs below 650°C, and the maximum operating temperature of GH4141 and GH4282 is generally less than 950°C. For occasions where spring components are required at higher temperatures, the strength of high temperature alloy wire decreases sharply, resulting in the inability of the spring to effectively rebound and fail to play an elastic function. Therefore, the choice of wire for springs is greatly restricted.

[0003] Molybdenum and its alloys have been widely used in high-temperature fields due to their advantages such as high melting point, high high-temperature strength, suitable density and low linear expansion coefficient. However, after deep processing into wire, molybdenum has poor winding performance, easy splitting and insufficient high-temperature stability, and is generally not suitable for spring wire. However, after alloying and second-phase strengthening, the toughness and high-temperature stability of the material are significantly improved; by introducing rhenium into molybdenum, the toughness of the material can be greatly improved while playing a role of solid solution strengthening. The introduction of tungsten and trace rare earth second phases into molybdenum can significantly improve the high-temperature strength of the material and improve the high-temperature creep resistance of molybdenum-rhenium alloys.

[0004] In order to meet the demand for wire materials for springs above 1000℃, the reinforced molybdenum alloy with molybdenum as the main element, rhenium and tungsten as alloy strengthening elements, and rare earth lanthanum oxide as the second phase strengthening phase can meet the material system requirements of alloys for high-temperature springs.

[0005] Molybdenum alloy wire is generally produced by powder metallurgy combined with hot drawing, including powder pretreatment, screening, charging and pressing, sintering, forging, drawing and other processes. The preparation of reinforced molybdenum alloy by this process has the characteristics of high production efficiency, controllable cost, and suitability for mass production. It is a reasonable choice for the preparation of alloy wire for high-temperature springs.

[0006] Therefore, those skilled in the art are committed to developing a reinforced molybdenum alloy wire with higher room temperature and high temperature strength, lower elastic modulus, good winding and bending properties, and suitable for high temperature springs, and a preparation method thereof. Summary of the invention

[0007] The purpose of the present invention is to provide a reinforced molybdenum alloy wire with higher room temperature and high temperature strength, lower elastic modulus, good winding and bending properties, suitable for high temperature springs and a preparation method thereof in view of the corresponding deficiencies of the prior art.

[0008] The objective of the present invention is achieved by adopting the following scheme:

[0009] A reinforced molybdenum alloy wire material comprises, by weight percentage: Re 2-22wt%, W 0.5-50wt%, La 0.1-1.0wt%, and the balance Mo.

[0010] Further, calculated by weight percentage: Re 22wt%, W 25wt%, La 1.0wt%, and the balance is Mo.

[0011] The present invention also provides a method for preparing the above-mentioned reinforced molybdenum alloy wire, comprising the following steps:

[0012] S1. Raw material ratio: Mo powder, NH4ReO4, LaN3O9·6H2O and W powder according to the ratio of claim 1 or 2;

[0013] S2. Evaporation crystallization: NH4ReO4 and LaN3O9·6H2O are mixed and crystallized to obtain a crystallization raw material;

[0014] S3. Mixing: The Mo powder, the crystallization raw material and the W powder are ball-milled to obtain a ball-milled mixture;

[0015] S4 Calcination: The ball milled mixture is placed in a hydrogen calciner to obtain a calcined mixture;

[0016] S5. Compounding: The calcined mixture is ball-milled to obtain a compound mixture;

[0017] S6. Reduction: The compounded mixture is reduced in a hydrogen reduction furnace to obtain a reduced pre-alloyed powder;

[0018] S7. Pressing: placing the reduced pre-alloyed powder in a mold and pressing it into an alloy compact;

[0019] S8. Vertical melting: The alloy pressed billet is vertically melted and sintered, and cooled to room temperature to obtain a billet after vertical melting;

[0020] S9. Rotary forging: Rotary forging the billet after vertical melting to forge it into a billet of φ3-5mm;

[0021] S10. Chain drawing: draw φ3~5mm billets into φ1.3~2mm wires;

[0022] S11. Fine drawing: drawing φ1.3~2mm wire into wire of required size;

[0023] S12. Electrolytic polishing: electrolytically polishing the wire of required size to remove fine defects on the surface of the wire of required size to obtain a polished wire;

[0024] S13. Heat treatment: The polished wire is subjected to continuous annealing treatment to obtain a finished wire product.

[0025] Further, in step S2, NH4ReO4 and LaN3O9·6H2O are mixed, deionized pure water is added at a ratio of not less than 1L / 100g, and the temperature is raised to 110°C under continuous stirring. After the raw materials are fully dissolved, the mixture is continuously stirred at a rate of 50 to 150 r / min to evaporate the solution and precipitate a crystalline mixture; after the raw materials are fully crystallized, they are cooled to room temperature and dried at 80°C for 5 to 20 hours, and then crushed and sieved at 120 mesh.

[0026] Further, in step S3, the ball milling mixing time is 25 h;

[0027] Furthermore, in step S4, the ball-milled mixture is calcined in a hydrogen calcining furnace at a temperature of 250 to 500° C. for 2 to 5 hours to obtain a calcined mixture.

[0028] Further, in step S5, the ball milling mixing time is 15 h;

[0029] Furthermore, in step S6, the compounded mixture is reduced in a hydrogen reduction furnace at a reduction temperature of 1100-1300° C. for 2-5 hours to obtain a reduced pre-alloyed powder.

[0030] Further, in step S7, the reduced pre-alloyed powder is placed in a rubber mold sleeve, and pressed in a cold isostatic press, with a pressing pressure of 180 to 250 MPa and a holding time of 60 to 200 seconds, and then taken out after decompression to obtain an alloy blank;

[0031] Furthermore, in step S8, the alloy blank is placed in a vertical melting furnace for vertical melting sintering, with a current of 2500-3500A and a holding time of 40-220min, and then cooled to room temperature in the furnace.

[0032] Further, in step S9, the vertically melted billet is placed on a rotary forging machine for rotary forging, with a forging temperature of 1350-1700° C. and a deformation amount of 10-15% to forge a billet of φ3-5 mm;

[0033] Furthermore, in step S10, the φ3-5 mm billet is placed in a chain drawing machine for chain drawing, with a drawing temperature of 600-1200° C., a deformation amount of 7-12%, and drawing to φ1.3-2 mm wire.

[0034] Furthermore, in step S11, a φ1.3-2 mm wire is placed in a drawing machine for fine drawing, with a drawing temperature of 500-1000° C. and a deformation amount of 5-10% per pass, until the wire is drawn to a required size;

[0035] Furthermore, in step S12, the wire of required size is electropolished in a NaOH solution, with an electrolytic wire washing rate of 150-300 r / min and an electrolytic current of 5-20 A to wash away fine defects on the surface of the wire.

[0036] Furthermore, in step S13, the electropolished wire is subjected to continuous annealing treatment in a hydrogen reduction furnace, with a heat treatment temperature of 1000-1300° C. and a wire feeding speed of 5-10 r / min.

[0037] The advantages of the present invention are:

[0038] (1) By using rhenium and tungsten as alloy strengthening elements and rare earth lanthanum oxide as the second phase strengthening phase, and optimizing the molybdenum alloy composition ratio, an alloy wire with excellent mechanical properties that can be used for spring winding was prepared. The wire has the technical characteristics of low elastic modulus, high yield strength, and relatively high high temperature strength.

[0039] (2) The reinforced molybdenum alloy wire prepared by this method has uniform microstructure in the processed state and uniform microstructure after heat treatment without abnormal growth. This is beneficial to maintain the high-temperature microstructure stability of the alloy wire, and further to maintain the performance stability of the spring under high-temperature working conditions.

[0040] (3) The surface quality of the reinforced molybdenum alloy wire prepared by this method is good, the surface is smooth, and there is no burr or cracking.

[0041] (4) The reinforced molybdenum alloy wire prepared by this method has good torsion and bending properties, which ensures the batch spring winding of coiled wire and realizes engineering application.

[0042] (5) Springs wound with reinforced molybdenum alloy wire can be used under working conditions in the range of 1400°C, which broadens the application range of high-temperature elastic components.

[0043] (6) Experimental verification: The room temperature tensile strength of the Φ1.0 mm alloy wire can reach 1230 MPa, the yield strength can reach 1079 MPa, and the elastic modulus is 260 GPa, with the technical characteristics of low elastic modulus and high yield strength. The tensile strength of the wire at 1200°C can reach 431 MPa, and the yield strength can reach 344 MPa. The tensile strength of the wire at 1400°C can reach 384 MPa, and the yield strength can reach 342 MPa, with the technical characteristics of high high temperature strength. In addition, the alloy wire has a unidirectional torsion fracture range of 18 to 25 cycles, and a repeated bending fracture range of 15 to 20 times. It has good torsion and bending properties, and is a reinforced molybdenum alloy wire suitable for high temperature springs and can be used for mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 is a process flow chart of the preparation method of the present invention;

[0045] Figure 2 The room temperature mechanical properties of the wire material of Example 1;

[0046] Figure 3 The high temperature mechanical properties of the wire of Example 1 (left: 1200°C; right: 1400°C);

[0047] Figure 4 The metallographic structure of the wire in the processed state of Example 1 (left: cross section; right: longitudinal section);

[0048] Figure 5 The metallographic structure of the wire in annealed state of Example 1 (left: cross section; right: longitudinal section);

[0049] Figure 6 The surface morphology of the wire material in Example 1;

[0050] Figure 7 The torsion and bending performance results of the wire material of Example 1 (left: unidirectional torsion; right: repeated bending). DETAILED DESCRIPTION

[0051] In order to enable those skilled in the art to understand the characteristics and effects of the present application, the following is a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used herein have the common meanings understood by those skilled in the art for the present application. In case of conflict, the definitions in this specification shall prevail.

[0052] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present application in any way, that is, the content of the present application can be implemented without being limited by any specific theory or mechanism.

[0053] As used herein, "this application" means "the present invention" or "the present disclosure".

[0054] The use of "one", "an", "a kind" or similar expressions to describe the components and technical features described in this application is merely for the convenience of expression and to provide a general meaning to the scope of this application. Therefore, such description should be understood to include one or at least one, and the singular also includes the plural, unless it is obvious that it refers to another meaning.

[0055] In this document, "or its combination" means "or any combination thereof", and "any one", "any one" means "any one", "any one" or "any one".

[0056] As used herein, the terms "comprises," "including," "having," "containing" or any other similar terms are open-ended transitional phrases, which are intended to cover non-exclusive inclusions. For example, a composition or product containing multiple elements is not limited to the elements listed herein, but may also include other elements that are not explicitly listed but are generally inherent to the composition or product. In addition, unless otherwise expressly stated, the term "or" refers to an inclusive "or" rather than an exclusive "or." For example, any of the following situations satisfies the condition "A or B": A is true (or exists) and B is false (or does not exist), A is false (or does not exist) and B is true (or exists), and both A and B are true (or exist). In addition, in this article, the terms "comprising", "including", "having", and "containing" should be interpreted as being specifically disclosed and simultaneously covering closed connections such as "consisting of", "consisting of", "the remainder of", and "substantially consisting of", "mainly consisting of", "mainly consisting of", "basically containing", "essentially consisting of", "essentially consisting of", "essentially containing", and other connecting words.

[0057] In this article, all features or conditions such as numerical values, quantities, contents and concentrations defined in the form of numerical ranges or percentage ranges are only for simplicity and convenience. Accordingly, the description of numerical ranges or percentage ranges should be deemed to have covered and specifically disclosed all possible sub-ranges and individual values ​​within the range (including integers and fractions), especially integer values. For example, the range description of "1.0 to 8.0" or "between 1.0 and 8.0" or "between 1.0 and 8.0" should be deemed to have specifically disclosed all sub-ranges such as 1.0 to 8.0, 1.0 to 7.0, 2.0 to 8.0, 2.0 to 6.0, 3.0 to 6.0, 4.0 to 8.0, 3.0 to 8.0, etc., and should be deemed to cover endpoint values, especially sub-ranges defined by integer values, and should be deemed to have specifically disclosed individual values ​​such as 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, etc. Unless otherwise indicated, the foregoing method of interpretation applies to all contents of the entire application, regardless of whether the scope is broad or not.

[0058] If the quantity, concentration or other numerical value or parameter is expressed as a range, a preferred range (or a better range) or a series of upper and lower limits, it should be understood that all ranges consisting of any pair of the upper limit or preferred value (or a better value) of the range and the lower limit or preferred value (or a better value) of the range have been specifically disclosed herein, regardless of whether these ranges are disclosed separately. In addition, if a numerical range is mentioned herein, unless otherwise specified, the range should include its endpoints and all integers and fractions within the range.

[0059] In this document, numerical values ​​should be understood to have the accuracy of the number of significant digits of the numerical value, provided that the purpose of the invention can be achieved. For example, the number 40.0 should be understood to cover the range of 39.50 to 40.49.

[0060] It should be understood that the features disclosed in the various embodiments herein may be arbitrarily combined to form the technical solution of the present application, as long as there is no contradiction in the combination of these features.

[0061] The present application will be described below with specific implementations and examples. It should be understood that these specific implementations and examples are merely illustrative and are not intended to limit the scope of the present application and its use.

[0062] Unless otherwise specified, the methods, reagents and conditions used in the preparation examples, comparative examples and embodiments below are conventional methods, reagents and conditions in the art. The following equipment and raw materials are from the following sources:

[0063] NH4ReO4: Manufacturer: Zhuzhou Purui Materials Co., Ltd., purity: 99.9%.

[0064] LaN3O9·6H2O: Manufacturer: Shanghai Aladdin Biochemical Technology Co., Ltd., purity: 99.99%.

[0065] Hydrogen roasting furnace: Manufacturer: Chongqing Tongda Industrial Furnace Co., Ltd., Model specification: non-standard.

[0066] Hydrogen reduction furnace: Manufacturer: Chongqing Feiyao Electric Furnace Co., Ltd., model specification: RX5-50-14.

[0067] Vertical melting furnace: Manufacturer: Xinzhou Jinda Tungsten Molybdenum Equipment Co., Ltd. Model specification: WCR2-C.

[0068] Rotary forging machine: Manufacturer: Northwest Machinery Factory, model specification: B202.

[0069] Chain drawing machine: Manufacturer: non-standard self-made, model specification: 1000 kg.

[0070] NaOH solution: NaOH is a common chemical reagent with a purity of AR and a solution concentration of 20-30 mol / L.

[0071] Example 1

[0072] Production 5Kg, Mo3Re 10 W~0.25La2O3,φ1.0mm alloy wire. Figure 1 Process flow diagram shown.

[0073] S1. Raw material ratio: Mo powder, NH4ReO4, LaN3O9·6H2O and W powder are mixed according to demand. 5 kg of raw materials require Mo: 4325 g, Re: 150 g, W: 500 g, La: 25 g, of which 216.1 g is required to convert Re into NH4ReO4, and 77.9 g is required to convert La into LaN3O9·6H2O.

[0074] S2. Evaporation crystallization: Mix NH4ReO4 and LaN3O9·6H2O to obtain a crystallization raw material. Place 216.1g NH4ReO4 and 77.9g LaN3O9·6H2O in an evaporation stirring container, add 3L of deionized pure water at a ratio of not less than 1L / 100g, and heat to 110°C under continuous stirring. After the raw material is fully dissolved, stir continuously at a rate of 100r / min to evaporate the solution and precipitate a crystal mixture. After the raw material is fully crystallized, cool it to room temperature and dry it in an oven at 80°C for 10h, then crush it and sieve it at 120 mesh.

[0075] S3. Mixing: Mo powder, crystallization raw material and W powder are mixed according to the above-mentioned calculated ratio and ball-milled for 25 hours to obtain a ball-milled mixture.

[0076] S4. Calcination: The ball-milled mixture is placed in a hydrogen calcination furnace for calcination to obtain a calcined mixture at a temperature of 300° C. for 3 h.

[0077] S5. Compounding: ball milling the calcined mixture to obtain a mixture after compounding for 15 hours.

[0078] S6. Reduction: The compounded mixture is reduced in a hydrogen reduction furnace to obtain reduced pre-alloyed powder, the reduction temperature is 1300° C., and the time is 5 h.

[0079] S7. Pressing: Place the reduced pre-alloyed powder in a mold and press it into an alloy blank. Fill the reduced pre-alloyed powder into a φ40 (inner diameter) × 850mm rubber mold sleeve, seal both ends and press it in a cold isostatic press. The pressing pressure is 250MPa and the holding time is 150s. After decompression, take out the alloy blank to obtain a blank size of φ36×800mm.

[0080] S8. Vertical melting: The alloy billet is placed in a vertical melting furnace for vertical melting sintering, with a current of 3500A and a holding time of 220min. It is then cooled to room temperature with the furnace to obtain a billet after vertical melting. The size of the billet after vertical melting is φ28×520mm.

[0081] S9. Rotary forging: Place the billet after vertical melting on a rotary forging machine for rotary forging. The initial forging temperature is 1700°C, the subsequent forging temperature is 1600°C, the deformation per pass is 12%, and the billet is forged to φ5mm.

[0082] S10. Chain drawing: Put the φ5mm billet into the chain drawing machine for chain drawing, the drawing temperature is 800~1200℃, the deformation amount per pass is 10%, and the wire is drawn to φ2mm. ;

[0083] S11. Fine drawing: Put the φ2mm wire into the drawing machine for fine drawing. The fine drawing adopts a polycrystalline wire drawing die, the drawing temperature is 1000℃, the deformation amount per pass is 6%, and the wire is drawn to φ1.0mm.

[0084] S12. Electrolytic polishing: The φ1.0 mm wire is electropolished in a NaOH solution at a rate of 250 r / min and an electrolytic current of 18 A to wash away fine defects on the surface of the wire and obtain a polished wire.

[0085] S13. Heat treatment: The polished wire is subjected to continuous annealing treatment in a hydrogen reduction furnace at a heat treatment temperature of 1300° C. and a wire feed rate of 10 r / min, to finally obtain a reinforced molybdenum alloy wire product.

[0086] Example 2

[0087] Production 5Kg, Mo2Re 0.5 W~0.1La2O3,φ1.5mm alloy wire. Figure 1 Process flow diagram shown.

[0088] S1. Raw material ratio: Mo powder, NH4ReO4, LaN3O9·6H2O and W powder are mixed according to demand. 5 kg of raw materials require Mo: 4650 g, Re: 100 g, W: 250 g, La: 5 g, of which 144.1 g is required to be converted into NH4ReO4, and 15.6 g is required to be converted into LaN3O9·6H2O.

[0089] S2. Evaporation crystallization: Place 144.1g NH4ReO4 and 15.6g LaN3O9·6H2O in an evaporation stirring container, add 2L of deionized pure water at a ratio of not less than 1L / 100g, and heat to 110°C under continuous stirring. After the raw materials are fully dissolved, stir continuously at a rate of 80r / min to evaporate the solution and precipitate a crystalline mixture. After the raw materials are fully crystallized, cool to room temperature and dry in an oven at 80°C for 5h, then crush and sieve at 120 mesh.

[0090] S3. Mixing: Mo powder, crystallization raw material and W powder are mixed according to the above-mentioned calculated ratio and ball-milled for 25 hours to obtain a ball-milled mixture.

[0091] S4. Calcination: The ball-milled mixture is placed in a hydrogen calcination furnace for calcination to obtain a calcined mixture at a temperature of 280° C. for 3 h.

[0092] S5. Compounding: ball milling the calcined mixture to obtain a mixture after compounding for 15 hours.

[0093] S6. Reduction: The compounded mixture is reduced in a hydrogen reduction furnace to obtain reduced pre-alloyed powder, the reduction temperature is 1300° C., and the time is 5 h.

[0094] S7. Pressing: Place the reduced pre-alloyed powder in a mold and press it into an alloy blank. Fill the reduced pre-alloyed powder into a φ40 (inner diameter) × 850mm rubber mold sleeve, seal both ends and press it in a cold isostatic press. The pressing pressure is 250MPa and the holding time is 150s. After decompression, take out the alloy blank to obtain a blank size of φ36×800mm.

[0095] S8. Vertical melting: The alloy billet is placed in a vertical melting furnace for vertical melting sintering, with a current of 3500A and a holding time of 220min. It is then cooled to room temperature with the furnace to obtain a billet after vertical melting. The size of the billet after vertical melting is φ28×520mm.

[0096] S9. Rotary forging: Place the billet after vertical melting on a rotary forging machine for rotary forging. The initial forging temperature is 1650°C, the subsequent forging temperature is 1600°C, the deformation per pass is 12%, and the billet is forged to φ5mm.

[0097] S10. Chain drawing: Put the φ5mm billet into the chain drawing machine for chain drawing, the drawing temperature is 800~1200℃, the deformation amount per pass is 10%, and the wire is drawn to φ2mm. ;

[0098] S11. Fine drawing: Put the φ2mm wire into the drawing machine for fine drawing. The fine drawing adopts a polycrystalline wire drawing die, the drawing temperature is 1000℃, the deformation amount per pass is 6%, and the wire is drawn to φ1.5mm.

[0099] S12. Electrolytic polishing: The φ1.5 mm wire is electropolished in a NaOH solution at a rate of 250 r / min and an electrolytic current of 15 A to wash away fine defects on the surface of the wire and obtain a polished wire.

[0100] S13. Heat treatment: The polished wire is subjected to continuous annealing treatment in a hydrogen reduction furnace at a heat treatment temperature of 1100° C. and a wire feed rate of 10 r / min, and finally a reinforced molybdenum alloy wire product is obtained.

[0101] Example 3

[0102] Production 5Kg, Mo 22 Re 25 W~1.0La2O3,φ0.8mm alloy wire. Figure 1 Process flow diagram shown.

[0103] S1. Raw material ratio: Mo powder, NH4ReO4, LaN3O9·6H2O and W powder are mixed according to demand. 5 kg of raw materials require Mo: 2600 g, Re: 1100 g, W: 1250 g, La: 50 g, of which 1584.7 g is required to convert Re into NH4ReO4, and 155.9 g is required to convert La into LaN3O9·6H2O.

[0104] S2. Evaporation crystallization: Place 1584.7g NH4ReO4 and 155.9LaN3O9·6H2O in an evaporation stirring container, add 20L of deionized pure water at a ratio of not less than 1L / 100g, and heat to 110°C under continuous stirring. After the raw materials are fully dissolved, stir continuously at a rate of 150r / min to evaporate the solution and precipitate a crystalline mixture. After the raw materials are fully crystallized, cool to room temperature and dry in an oven at 80°C for 20h, then crush and sieve at 120 mesh.

[0105] S3. Mixing: Mo powder, crystallization raw material and W powder are mixed according to the above-mentioned calculated ratio and ball-milled for 25 hours to obtain a ball-milled mixture.

[0106] S4. Calcination: The ball-milled mixture is placed in a hydrogen calcination furnace for calcination to obtain a calcined mixture at a temperature of 500° C. for 5 h.

[0107] S5. Compounding: ball milling the calcined mixture to obtain a mixture after compounding for 15 hours.

[0108] S6. Reduction: The compounded mixture is reduced in a hydrogen reduction furnace to obtain reduced pre-alloyed powder, the reduction temperature is 1300° C., and the time is 5 h.

[0109] S7. Pressing: Place the reduced pre-alloyed powder in a mold and press it into an alloy blank. Fill the reduced pre-alloyed powder into a φ40 (inner diameter) × 850mm rubber mold sleeve, seal both ends and press it in a cold isostatic press. The pressing pressure is 250MPa and the holding time is 150s. After decompression, take out the alloy blank to obtain a blank size of φ36×810mm.

[0110] S8. Vertical melting: The alloy billet is placed in a vertical melting furnace for vertical melting sintering, with a current of 3500A and a holding time of 220min. It is then cooled to room temperature with the furnace to obtain a billet after vertical melting. The size of the billet after vertical melting is φ28×525mm.

[0111] S9. Rotary forging: Place the billet after vertical melting on a rotary forging machine for rotary forging. The initial forging temperature is 1700℃, the subsequent forging temperature is 1650℃, the deformation amount per pass is 10%, and the billet is forged to φ5mm.

[0112] S10. Chain drawing: Put the φ5mm billet into the chain drawing machine for chain drawing, the drawing temperature is 900~1200℃, the deformation amount per pass is 10%, and the wire is drawn to φ1.5mm. ;

[0113] S11. Fine drawing: Place the φ1.5mm wire into the drawing machine for fine drawing. Fine drawing uses a polycrystalline wire drawing die, a drawing temperature of 1000℃, a deformation of 6% per pass, and is drawn to φ0.8mm wire.

[0114] S12. Electrolytic polishing: The φ1.5 mm wire was electropolished in a NaOH solution at a rate of 200 r / min and an electrolytic current of 15 A to wash away fine defects on the surface of the wire and obtain a polished wire.

[0115] S13. Heat treatment: The polished wire is subjected to continuous annealing treatment in a hydrogen reduction furnace at a heat treatment temperature of 1300° C. and a wire feed rate of 5 r / min, and finally a reinforced molybdenum alloy wire product is obtained.

[0116] The finished wire material obtained in Example 1 was subjected to the following tests, and the results were as follows:

[0117] 1. Conduct mechanical property test. The test is carried out on an electronic universal testing machine. The room temperature test is based on GB / T228.1 "Metallic material tensile test Part 1: Room temperature test method", and the high temperature test is based on GB / T228.2 "Metallic material tensile test Part 2: High temperature test method". The results are as follows: Figure 2 , Figure 3 shown.

[0118] 2. Observe the metallographic structure. Take the cross section and longitudinal section of the wire, mount them on the mounting machine, and then polish and etch them before observing them under a metallographic microscope. The observation magnification is 500 times. The results are as follows: Figure 4 , Figure 5 shown.

[0119] 3. Observe the surface of the finished wire under a magnifying glass with a magnification of 1.5 times. Figure 6 shown.

[0120] 4. Randomly select 5 parts of the finished coiled wire and place them on the torsion tester and bending tester respectively. Test them according to GBT239.1 "Metallic wire Part 1: Unidirectional torsion test method" and GBT 238 "Metallic wire repeated bending test method". The results are as follows: Figure 7 shown.

[0121] in conclusion

[0122] 1. The room temperature tensile strength of Φ1.0mm alloy wire can reach 1230MPa, the yield strength can reach 1079MPa, and the elastic modulus is 260GPa, with the technical characteristics of low elastic modulus and high yield strength. The tensile strength of the wire at 1200℃ can reach 431MPa, and the yield strength can reach 344MPa. The tensile strength of the wire at 1400℃ can reach 384MPa, and the yield strength can reach 342MPa, with the technical characteristics of high high temperature strength.

[0123] 2. The Φ1.0mm reinforced molybdenum alloy wire has uniform structure in the processed state. After heat treatment, the wire structure is recrystallized and has uniform structure without abnormal growth.

[0124] 3.Φ1.0mm reinforced molybdenum alloy wire has good surface quality, smooth surface, no burrs or cracks

[0125] 4. The unidirectional torsion fracture of Φ1.0mm reinforced molybdenum alloy wire is in the range of 18 to 25 cycles, and the repeated bending fracture is in the range of 15 to 20 times, and it has good torsion and bending performance.

[0126] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification made to the present invention by those skilled in the art without departing from the spirit of the present invention shall fall within the protection scope of the present invention.

Claims

1. A reinforced molybdenum alloy wire, characterized in that: Calculated by weight percentage: Re 2~22wt%, W 0.5~50wt%, La 0.1~1.0wt%, and the balance is Mo.

2. The reinforced molybdenum alloy wire according to claim 1, characterized in that: Calculated by weight percentage: Re 22wt%, W 25wt%, La 1.0wt%, and the balance is Mo.

3. A method for preparing the reinforced molybdenum alloy wire according to claim 1 or 2, characterized in that: The following steps are involved: S1. Raw material ratio: Mo powder, NH4ReO4, LaN3O9·6H2O and W powder according to the ratio of claim 1 or 2; S2. Evaporation crystallization: NH4ReO4 and LaN3O9·6H2O are mixed and crystallized to obtain a crystallization raw material; S3. Mixing: The Mo powder, the crystallization raw material and the W powder are ball-milled to obtain a ball-milled mixture; S4 Calcination: The ball milled mixture is placed in a hydrogen calciner to obtain a calcined mixture; S5. Compounding: The calcined mixture is ball-milled to obtain a compound mixture; S6. Reduction: The compounded mixture is reduced in a hydrogen reduction furnace to obtain a reduced pre-alloyed powder; S7. Pressing: placing the reduced pre-alloyed powder in a mold and pressing it into an alloy compact; S8. Vertical melting: The alloy pressed billet is vertically melted and sintered, and cooled to room temperature to obtain a billet after vertical melting; S9. Rotary forging: Rotary forging the billet after vertical melting to forge it into a billet of φ3-5mm; S10. Chain drawing: draw φ3~5mm billets into φ1.3~2mm wires; S11. Fine drawing: drawing φ1.3~2mm wire into wire of required size; S12. Electrolytic polishing: electrolytically polishing the wire of required size to remove fine defects on the surface of the wire of required size to obtain a polished wire; S13. Heat treatment: The polished wire is subjected to continuous annealing treatment to obtain a finished wire product.

4. The method for preparing the reinforced molybdenum alloy wire according to claim 3, characterized in that: In step S2, NH4ReO4 and LaN3O9·6H2O are mixed, and deionized pure water is added at a ratio of not less than 1L / 100g, and the temperature is raised to 110°C under continuous stirring. After the raw materials are fully dissolved, the mixture is continuously stirred at a rate of 50 to 150 r / min to evaporate the solution and precipitate a crystalline mixture; after the raw materials are fully crystallized, they are cooled to room temperature and dried at 80°C for 5 to 20 hours, and then crushed and sieved at 120 mesh.

5. The method for preparing the reinforced molybdenum alloy wire according to claim 3, characterized in that: In step S3, the ball milling mixing time is 25 h; In step S4, the ball-milled mixture is calcined in a hydrogen calcining furnace at a temperature of 250-500° C. for 2-5 hours to obtain a calcined mixture.

6. The method for preparing the reinforced molybdenum alloy wire according to claim 3, characterized in that: In step S5, the ball milling mixing time is 15 hours; In step S6, the compounded mixture is reduced in a hydrogen reduction furnace at a reduction temperature of 1100-1300° C. for 2-5 hours to obtain reduced pre-alloyed powder.

7. The method for preparing the reinforced molybdenum alloy wire according to claim 3, characterized in that: In step S7, the reduced pre-alloyed powder is placed in a rubber mold sleeve, and pressed in a cold isostatic press at a pressing pressure of 180 to 250 MPa and a holding time of 60 to 200 seconds. After decompression, the alloy blank is taken out to obtain; In step S8, the alloy blank is placed in a vertical melting furnace for vertical melting sintering, with a current of 2500-3500A and a holding time of 40-220min, and then cooled to room temperature in the furnace.

8. The method for preparing the reinforced molybdenum alloy wire according to claim 3, characterized in that: In step S9, the vertically melted billet is placed on a rotary forging machine for rotary forging, with a forging temperature of 1350-1700°C and a deformation amount of 10-15% to forge a billet of φ3-5 mm; In step S10, a φ3-5 mm billet is placed in a chain drawing machine for chain drawing at a drawing temperature of 600-1200° C. and a deformation amount of 7-12% to draw the billet into a φ1.3-2 mm wire.

9. The method for preparing the reinforced molybdenum alloy wire according to claim 3, characterized in that: In step S11, a φ1.3-2 mm wire is placed in a drawing machine for fine drawing, with a drawing temperature of 500-1000° C. and a deformation amount of 5-10% per pass, until the wire is drawn to a required size; In step S12, the wire of required size is electropolished in a NaOH solution, with an electrolytic wire washing rate of 150-300 r / min and an electrolytic current of 5-20 A to wash away fine defects on the surface of the wire.

10. The method for preparing the reinforced molybdenum alloy wire according to claim 3, characterized in that: In step S13, the electropolished wire is subjected to continuous annealing treatment in a hydrogen reduction furnace, with a heat treatment temperature of 1000-1300°C and a wire feeding speed of 5-10 r / min.

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