Preparation and use method for nb 5si 3 composite spheroidized powder

Abstract

A preparation and use method for an Nb5Si3 composite spheroidized powder. The preparation method comprises: A) mixing an Nb powder, an Si powder, PVA and water, and ball milling the resulting mixture to obtain a slurry; and subjecting the slurry to spray granulation and sieving, so as to obtain an Nb5Si3 composite agglomerated powder; and B) subjecting the Nb5Si3 composite agglomerated powder to plasma spheroidization to obtain the product. The use method comprises mixing the Nb5Si3 composite spheroidized powder with NbTiX, wherein X is three or more of Zr, Hf, V, Mo and Ta; Nb and Si in the raw materials are subjected to an in-situ reaction during a laser additive melting process; and in combination with a rapid solidification process, a submicron Nb5Si3 particle-reinforced Nb5Si3 / Nbss dual-phase alloy can be obtained. Compared with a cast alloy having the same components, the Nb5Si3 particle-reinforced phase can be greatly reduced from a size level of dozens of microns to a submicron level, which greatly reduces the brittleness of the particle-reinforced refractory alloy, and significantly improves the strength of the particle-reinforced refractory alloy.

Description

Preparation and use method of Nb5Si3 composite spheroidized powder

[0001] This application claims priority to the Chinese patent application filed with the Patent Office of China on December 6, 2023, with application number 202311667839.6 and invention name “A method for preparing and using Nb5Si3 composite spheroidized powder”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present invention belongs to the field of material technology, and in particular relates to a Nb5Si3 composite spheroidized powder, a preparation method thereof, and a method for using the composite powder. Background Art

[0003] Composed of Nb5Si3 high temperature strengthening phase and Nb solid solution (Nb SS ) Room temperature toughening phase composition Nb5Si3 / Nb SS Refractory duplex alloys have the potential to achieve a good balance of mechanical properties and are currently a hot topic in the development of a new generation of ultra-high temperature structural materials with a temperature range of 1200-1300°C. Traditional melting and casting processes inevitably produce problems such as segregation, uneven structure, and coarse grains. The size of the Nb5Si3 high-temperature strengthening phase is often as large as tens of microns, which seriously damages the alloy properties, especially toughness. As a result, the existing cast Nb5Si3 / Nb SS Refractory duplex alloys generally have a mismatch between strength and toughness at room temperature and at medium and low temperatures, among which insufficient room temperature plasticity and toughness is the most prominent problem, which seriously affects the Nb5Si3 / Nb SS Technical maturity and engineering applications of refractory duplex alloys. Summary of the Invention

[0004] In view of this, the object of the present invention is to provide a Nb5Si3 composite spheroidized powder. The size of the Nb-Si composite spheroidized powder provided by the present invention is reduced to the submicron level, and the Nb5Si3 particles are dispersed, which greatly reduces the brittleness of the particle-reinforced refractory alloy.

[0005] The present invention provides a method for preparing Nb5Si3 composite spheroidized powder, comprising the following steps:

[0006] A) mixing Nb powder, Si powder, PVA and water and ball milling to obtain a slurry; spray granulating the slurry and sieving to obtain a Nb-Si composite agglomerated powder;

[0007] B) The Nb-Si composite agglomerated powder is subjected to plasma spheroidization to obtain.

[0008] Preferably, the particle size of the Nb powder is 10-20 μm; the particle size of the Si powder is 1-5 μm.

[0009] Preferably, in step A), the mass ratio of the Nb powder, Si powder, PVA and water is (437.3-437.7): (262.3-262.7): (7.8-8.2): (1299.8-1300.2).

[0010] Preferably, the ball milling time in step A) is 12 hours, the ball-to-material ratio in the ball milling is 20:1, and the ball milling speed is 500 r·min -1 .

[0011] Preferably, the parameters of the spray granulation in step A) are: inlet temperature 300°C, outlet temperature 120°C, spray disk speed 40Hz, and feed rate 35rpm;

[0012] Preferably, the screening in step A) is specifically as follows: selecting 150-mesh and 300-mesh vibrating screens for screening, and setting the vibration amplitude to 0.2.

[0013] Preferably, the parameters of the plasma spheroidization in step B) are: current 700A, main gas 120SCFH, auxiliary gas 10SCFH, carrier gas 11SCFH, and powder feeding rate 2.0r / min.

[0014] The present invention provides a Nb-Si composite spheroidized powder, which is prepared by the preparation method described in any one of the above technical solutions.

[0015] The present invention provides a Nb5Si3 / Nbss two-phase alloy, the raw materials of which include the Nb-Si composite spheroidized powder described in the above technical solution.

[0016] The present invention provides a method for preparing a Nb5Si3 / Nbss dual-phase alloy, comprising the following steps:

[0017] The Nb-Si composite spheroidized powder described in the above technical solution is mixed with Nbss and the mixture is manufactured by a laser additive manufacturing method.

[0018] Compared with the prior art, the present invention provides a method for preparing Nb-Si composite spheroidized powder, comprising the following steps: A) ball-milling Nb powder, Si powder, PVA, and water to obtain a slurry; spray-granulating the slurry and screening it to obtain Nb-Si composite agglomerated powder; and B) plasma spheroidizing the Nb-Si composite agglomerated powder. The present invention utilizes Nb powder and Si powder in conjunction with the in-situ reaction between Nb and Si in the molten state during laser additive manufacturing and the rapid solidification process to obtain a Nb5Si3 / Nbss refractory alloy reinforced with submicron Nb5Si3 particles. Compared to a cast refractory alloy of the same composition, the size of the Nb5Si3 particle reinforcement phase can be significantly reduced from tens of microns to submicron size, greatly reducing the brittleness of the particle-reinforced refractory alloy. Simultaneously, based on the Orowan strengthening principle, the strength of the particle-reinforced refractory alloy is significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1. Morphology of original Nb and Si particles;

[0020] FIG2 shows the spheroidized contour and slight surface melting of the Nb-Si composite spheroidized powder prepared by the present invention. DETAILED DESCRIPTION

[0021] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0022] In this application, the term "and / or" describes the association relationship between associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural.

[0023] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items.

[0024] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. Some or all of the steps can be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0025] The Nb-Si composite spheroidized powder prepared by the present invention is Nb5Si3.

[0026] The present invention provides a method for preparing Nb5Si3 composite spheroidized powder, comprising the following steps:

[0027] A) mixing Nb powder, Si powder, PVA and water and ball milling to obtain a slurry; spray granulating the slurry and sieving to obtain a Nb-Si composite agglomerated powder;

[0028] B) The Nb-Si composite agglomerated powder is subjected to plasma spheroidization to obtain.

[0029] The preparation method of the Nb-Si composite spheroidized powder provided by the present invention firstly comprises a Nb-Si composite powder granulation process.

[0030] The present invention firstly mixes Nb powder, Si powder, PVA and water and performs ball milling to obtain slurry.

[0031] According to the present invention, the particle size of the Nb powder is 10-20 μm; the particle size of the Si powder is 1-5 μm.

[0032] According to the present invention, the mass ratio of the Nb powder, Si powder, PVA and water is (437.3-437.7): (262.3-262.7): (7.8-8.2): (1299.8-1300.2).

[0033] That is, their mass ratios are: Nb powder: 437.5±0.2; Si powder: 262.5±0.2; PVA: 8±0.2; deionized water: 1300±0.2. They are placed in a ball mill, and then the ball mill is fixed on a planetary ball mill and ball milled for 12 hours to obtain the required slurry.

[0034] The parameters are as follows: the ball milling time is 12 h, the ball-to-material ratio is 20:1, and the rotor speed is 500 r·min -1 .

[0035] The slurry is spray granulated; according to the present invention, the parameters of the spray granulation are: inlet temperature 300°C, outlet temperature 120°C, spray disk speed 40Hz, and feed speed 35rpm.

[0036] The present invention preferably utilizes a spray dryer (LGZ-8) for spray granulation.

[0037] The spray granulation is followed by sieving to obtain Nb-Si composite agglomerated powder.

[0038] The screening method of the present invention is as follows: 150-mesh and 300-mesh vibrating screens are selected for screening, and the vibration amplitude is set to 0.2.

[0039] More preferably, the screening is specifically as follows: the agglomerated powder is screened using an oscillating sieving instrument, 150 mesh and 300 mesh vibrating sieves are selected for screening respectively, and the vibration amplitude is set to 0.2, so as to obtain Nb-Si composite agglomerated powder with a controllable particle size range.

[0040] The Nb-Si composite agglomerated powder is plasma spheroidized to obtain the product.

[0041] The Nb-Si composite agglomerated powder is placed into a plasma spheroidizing device to melt the surface of the Nb-Si composite agglomerated powder and to shape and spheroidize the powder.

[0042] The parameters of the plasma spheroidization of the present invention are: current 700A, main gas 120SCFH, auxiliary gas 10SCFH, carrier gas 11SCFH, and powder feeding rate 2.0r / min.

[0043] Finally, the Nb5Si3 composite spheroidized powder was detected and analyzed.

[0044] The detection and analysis of the Nb5Si3 composite spheroidized powder of the present invention are specifically as follows:

[0045] First, the surface and cross-sectional morphology of the composite spheroidized powder were observed by SEM to observe and analyze the sphericity, surface melting degree and density of the composite spheroidized powder. Then, the particle size analysis of the Nb5Si3 composite spheroidized powder was performed to obtain the characteristic values ​​of D10, D50 and D90 of this batch of powder, and all these test and analysis results were recorded.

[0046] The present invention provides a Nb-Si composite spheroidized powder, which is prepared by the preparation method described in any one of the above technical solutions.

[0047] The present invention has clearly described the above preparation method, which will not be repeated here.

[0048] The present invention provides a Nb5Si3 / Nbss two-phase alloy, the raw materials of which include the Nb-Si composite spheroidized powder described in the above technical solution.

[0049] The present invention provides a method for preparing a Nb5Si3 / Nbss dual-phase alloy, comprising the following steps:

[0050] The Nb-Si composite spheroidized powder described in the above technical solution is mixed with Nbss and the mixture is manufactured by a laser additive manufacturing method.

[0051] The present invention uses the prepared Nb-Si composite spheroidized powder, weighs the two powders according to the designed content ratio of Nb5Si3 and Nbss alloy, and obtains Nb5Si3 / Nbss refractory alloy reinforced with Nb5Si3 particles (submicron size) through laser additive manufacturing.

[0052] According to the present invention, the additive manufacturing is specifically: additive manufacturing is performed in the following manner:

[0053] According to the designed content ratio of Nb5Si3 and Nbss alloy, the two powders are weighed, mechanically mixed and then additively manufactured through a single-channel powder feeding method; the typical parameters of powder feeding laser additive manufacturing are laser power 800-1000W, scanning speed 600mm / min, and powder feeding rate 1000r / min.

[0054] The present invention does not limit the process parameters of the additive manufacturing, which are well known to those skilled in the art.

[0055] Using the Nb5Si3 composite spheroidized powder prepared by the present invention, the two powders are weighed according to the designed content ratio of Nb5Si3 and NbTiX (where X is three or more of Zr, Hf, V, Mo, and Ta) alloy, and laser additive manufacturing is used to obtain a Nb5Si3 particle-reinforced Nb5Si3 / Nbss two-phase refractory alloy, in which the Nb5Si3 particles are small and evenly distributed.

[0056] By using Si powder raw materials with a particle size of 2-5 microns and Nb powder raw materials with a particle size of 15-20 microns, granulated and composite spheroidized at an atomic ratio of 5:3, combined with the in-situ reaction between Nb and Si in the molten state during laser additive manufacturing and the rapid solidification process, a Nb5Si3 / Nbss refractory alloy reinforced with submicron-sized Nb5Si3 particles can be obtained. Compared with cast refractory alloys of the same composition, the size of the Nb5Si3 particles can be significantly reduced from tens of microns to submicron levels. The Nb5Si3 particles are also dispersed, greatly reducing the brittleness of the particle-reinforced refractory alloy. At the same time, based on the Orowan strengthening principle, the strength of the particle-reinforced refractory alloy is significantly improved. This is a significant technological advancement in this field.

[0057] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. Some or all of the steps can be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0058] In order to further illustrate the present invention, a Nb-Si composite spheroidized powder and a preparation method thereof and a Nb5Si3 / Nbss dual-phase alloy provided by the present invention are described in detail below with reference to examples.

[0059] Example 1

[0060] (1) The particle size of Si powder raw material is selected to be 1-5 μm, and the particle size of Nb powder raw material is selected to be 10-20 μm (see Figure 1). Nb powder, Si powder, PVA, and deionized water are weighed in order according to the mass ratio. Their mass ratios are as follows: Nb powder: 437.5; Si powder: 262.5; PVA: 8; deionized water: 1300. They are placed in a ball mill, and then the ball mill is fixed on a planetary ball mill and ball milled for 12 hours to obtain the desired slurry.

[0061] Then spray granulation was performed: spray granulation was performed using a spray dryer (LGZ-8), and the process parameters for spray drying to prepare agglomerated powder were: inlet temperature 300°C, outlet temperature 120°C, spray disk speed 40Hz Hz, and feed rate 30rpm; then powder screening was performed: the agglomerated powder was screened using an oscillating sieving instrument, and 150-mesh and 300-mesh vibrating sieves were selected for screening respectively, and the vibration amplitude was set to 0.2 to obtain Nb-Si composite agglomerated powder with a controllable particle size range.

[0062] (2) 3 kg of Nb-Si composite agglomerated powder was weighed using an electronic balance and loaded into a plasma spheroidizing device for surface melting of the Nb-Si composite agglomerated powder and powder shaping and spheroidization. The process parameters of the plasma spheroidizing device were as follows: current 700 A, main gas 120 SCFH, auxiliary gas 10 SCFH, carrier gas 11 SCFH, and powder feeding rate 2.0 r / min.

[0063] (3) First, the surface and cross-sectional morphology of the composite spheroidized powder were observed by SEM to analyze the sphericity, surface melting degree, and density of the composite spheroidized powder. The particle size analysis of the Nb-Si composite spheroidized powder was then performed to obtain the characteristic values ​​of D10, D50, and D90 of this batch of powder. All these test and analysis results were recorded. As shown in Figures 1 and 2, Figure 1 shows the morphology of the original Nb and Si particles; Figure 2 shows the spheroidized contour and the surface melt consolidation state of the Nb-Si composite spheroidized powder prepared by the present invention.

[0064] The use effect of the above embodiment is as follows: using the prepared Nb-Si composite spheroidized powder (see Figure 2), the two powders are weighed according to the designed content ratio of Nb5Si3 and NbTiX (where X is three or more of Zr, Hf, V, Mo, and Ta) alloy (27:73). In this embodiment, NbTiX is specifically 20Ti-18Zr-20Hf-20Nb-12Ta-10Mo. Through laser additive manufacturing, a uniform and fine Nb5Si3 particle-reinforced Nb5Si3 / Nbss refractory alloy is obtained. The Nb5Si3 particle reinforcement phase generated by the in-situ reaction of Nb-Si during the laser additive manufacturing process is generally submicron in size, and the Nb5Si3 particles are dispersed. This greatly reduces the brittleness of the particle-reinforced refractory dual-phase alloy and significantly improves the strength of the particle-reinforced refractory alloy. The fracture toughness value of the alloy prepared using this process is 20.9MPa·m 1 / 2。 .

[0065] Example 2

[0066] A method for preparing and using Nb5Si3 composite spheroidized powder. The four steps (preparing a slurry containing Nb and Si powders, a Nb5Si3 composite powder spray granulation process, a Nb5Si3 composite powder plasma spheroidization process, and testing and analysis of the Nb5Si3 composite spheroidized powder) are the same as those in specific embodiment 1. However, it was found that after the initial plasma spheroidization treatment of the Nb5Si3 composite powder, the surface layer of the Nb5Si3 composite powder was not melted and consolidated, and the shaping and spheroidization effects were poor. Therefore, the process parameters in the plasma spheroidization process were appropriately adjusted, and the composite powder was subjected to a secondary plasma spheroidization treatment. Testing and analysis of the composite powder confirmed that the effects of surface melting and powder spheroidization were achieved.

[0067] The Nb5Si3 composite spheroidized powder after the above-mentioned secondary plasma spheroidization treatment was weighed with the Nb(X,Y,Z...) alloy in an appropriate proportion. Through laser additive manufacturing, a Nb5Si3 / Nbss refractory alloy reinforced with uniform and fine Nb5Si3 particles was obtained. The overall size level of the Nb5Si3 particle reinforcement phase was submicron, and the Nb5Si3 particles were dispersed. This not only reduced the brittleness of the particle-reinforced refractory dual-phase alloy, but also significantly improved the strength of the particle-reinforced refractory alloy.

[0068] The above description is only a preferred embodiment of the present invention and does not limit the scope of the patent of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification, for example, first preparing Nb(X,Y) binary or ternary alloy powder, where X,Y refer to elements such as Ti, Zr, V, Hf, etc.; and then preparing Nb(X,Y)-Si composite spheroidized powder, is similar in principle or the process flow is slightly extended and transformed, or is directly or indirectly applied to other related technical fields, are all included in the scope of patent protection of the present invention.

[0069] It should be noted that the above process operations can be applied in combination to different degrees. For the sake of simplicity, the implementation methods of various combinations will not be described in detail. Technical personnel in this field can flexibly adjust the order of the above operating steps according to actual needs, or flexibly combine the above steps.

[0070] The above embodiments are only used to illustrate the technical solutions of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. The specific embodiments described in the present invention may have different formulas, process names, etc. Any equivalent or simple changes based on the structure, features and principles described in the patent concept of the present invention are included in the patent protection scope of the present invention.

Claims

1. A method for preparing Nb5Si3 composite spheroidized powder, characterized in that: The steps include: A) mixing Nb powder, Si powder, PVA and water and ball-milling to obtain a slurry; spray-granulating the slurry and sieving to obtain a Nb5Si3 composite agglomerated powder; B) The Nb5Si3 composite agglomerated powder is plasma spheroidized to obtain.

2. The preparation method according to claim 1, characterized in that: The particle size of the Nb powder is 10-20 μm; the particle size of the Si powder is 1-5 μm.

3. The preparation method according to claim 1, characterized in that: In step A), the mass ratio of the Nb powder, Si powder, PVA and water is (437.3-437.7): (262.3-262.7): (7.8-8.2): (1299.8-1300.2).

4. The preparation method according to claim 1, characterized in that: Step A) The ball milling time is 12 hours, the ball-to-material ratio is 20:1, and the ball milling speed is 500 r·min -1 .

5. The preparation method according to claim 1, characterized in that: Step A) The parameters of the spray granulation are: inlet temperature 300°C, outlet temperature 120°C, spray disk speed 40Hz, feed speed 35rpm.

6. The preparation method according to claim 1, characterized in that: The screening in step A) is specifically as follows: 150-mesh and 300-mesh vibrating screens are selected for screening, and the vibration amplitude is set to 0.

2.

7. The preparation method according to claim 1, characterized in that: Step B) The parameters of plasma spheroidization are: current 700A, main gas 120SCFH, auxiliary gas 10SCFH, carrier gas 11SCFH, powder feeding rate 2.0r / min.

8. A Nb5Si3 composite spheroidized powder, characterized in that: The compound is prepared by the preparation method according to any one of claims 1 to 7.

9. A Nb5Si3 / Nbss dual-phase alloy, characterized in that: The raw material includes the Nb5Si3 composite spheroidized powder as described in claim 8.

10. A method for preparing a Nb5Si3 / Nbss dual-phase alloy, characterized in that: The steps include: The Nb5Si3 composite spheroidized powder according to claim 8 is mixed with NbTiX, and the mixture is obtained by a laser additive manufacturing method; wherein X is three or more of Zr, Hf, V, Mo, and Ta.

Images