Nanoscale particulate hybrid reinforced titanium matrix composite powder and method of making same

Abstract

The application discloses a kind of nanoscale particle hybrid reinforced titanium matrix composite powder and preparation method thereof, comprising the following steps: alloy block is pressed into alloy block with multiple reinforcement powders;Vacuum non-consumable melting is carried out to the alloy block, and embedded reinforcement alloy ingot is prepared;The alloy ingot is atomized to powder by ultrasonic, and the embedded uniform distribution nanoscale particle hybrid reinforced titanium matrix composite spherical powder is prepared.By the method of the application, not only can embedded reinforcement particle hybrid reinforced titanium matrix composite powder be prepared, but also the obtained powder has high sphericity, good surface quality, no porosity or fragmentation in the powder, and no satellite ball or adhesion phenomenon in the powder.

Description

Technical Field

[0001] The present invention relates to the technical field of metal powder preparation, in particular to a nano-level particle hybrid reinforced titanium-based composite material powder and a preparation method thereof. Background Art

[0002] Titanium-based composites, as a high-performance metal-based composite material, use titanium or titanium alloy as a matrix, and embed reinforcements such as fibers or particles into the matrix to significantly improve its mechanical properties. This material has the advantages of wear resistance, heat resistance, high strength and high hardness. It is widely used in aerospace, automotive and high-performance engineering applications, and shows great development potential. Traditional titanium-based composite preparation methods mainly include powder metallurgy and casting, both of which utilize in-situ reactions between the matrix and additives to synthesize reinforcements. However, due to the poor thermal conductivity of titanium-based composites, the introduction of hard reinforcements and the difficulty of processing, it is difficult to achieve near-net-shape processing of its integrated components, which limits its application in fields with high processing precision requirements such as biomedicine and high-end equipment manufacturing.

[0003] As a near-net-shape forming process, additive manufacturing has been widely used and recognized in recent decades. Additive manufacturing is based on a three-dimensional digital model and constructs parts of complex shapes by accumulating materials layer by layer. Its advantage is that it greatly expands the degree of freedom of design and can produce complex and multi-component metal structures. Therefore, additive manufacturing technology provides a feasible way to achieve near-net-shape forming of complex components made of particle-reinforced titanium-based composite materials in one step. The raw materials in the additive manufacturing process exist in the form of metal powder, wire or strip. Metal powder has high fluidity and adjustability, and its compatibility with various printing technologies and flexibility in constructing parts with diverse geometries effectively promotes high-precision and high-performance printing results, meeting the high standards required for industrial applications. In the additive manufacturing process, the morphology, particle size distribution, performance and quality of the metal powder are crucial to the integrity and mechanical properties of the component.

[0004] The preparation of titanium-based composite powder raw materials for additive manufacturing usually uses a mechanical mixing method, that is, the matrix alloy powder and the reinforcement powder are mixed and then subjected to high-energy ball milling to make the reinforcement powder adhere to the matrix alloy powder to form an externally embedded composite powder, and then the composite powder is used for additive manufacturing. This powder making method has problems such as irregular powder particle shape, poor powder fluidity, and a large size span and uneven distribution of reinforcements. In addition, due to the short laser processing time and rapid cooling, and the melting point of the reinforcement raw material is usually much higher than that of the matrix, it is difficult to completely melt it during the additive manufacturing process, and it is eventually deposited in the matrix to form defects, causing stress concentration or cracks, etc., which seriously affect the quality and mechanical properties of additively manufactured components. Summary of the Invention

[0005] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a nano-scale particle mixed reinforced titanium-based composite material powder and a preparation method thereof, aiming to solve the problem that the composite powder prepared by the traditional method has irregular particle shape, poor fluidity, and a large size span and uneven distribution of the reinforcement, which makes it difficult to completely melt and form deposition during use.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] In a first aspect, a method for preparing nano-particle hybrid reinforced titanium-based composite material powder comprises:

[0008] Step 1: grinding the base alloy block, mixing multiple reinforcement powders by mechanical mixing, adding them to the ground base alloy block, and pressing them into a block;

[0009] Step 2: melting the block into a titanium-based composite ingot in a vacuum non-consumable arc furnace;

[0010] Step 3: Powdering the titanium-based composite material ingot by ultrasonic atomization to obtain titanium-based composite material powder.

[0011] Furthermore, in step 1, the base alloy block is a Ti6Al4V alloy block, and the surface of the Ti6Al4V alloy block is polished with sandpaper to remove the surface oxide layer and impurities.

[0012] Furthermore, in step 1, adding the reinforcement powder to the polished base alloy block and pressing it into a block comprises:

[0013] The mass fractions of Ti6Al4V alloy block, reinforcement Si powder and TiB2 powder are 95.85%, 2.19% and 1.96%, respectively. Subsequently, the reinforcement Si powder and the reinforcement TiB2 powder are mechanically mixed at 200 rpm for 2 hours using a powder mixer, and then pressed into a block with the matrix Ti6Al4V alloy.

[0014] Furthermore, in step 1, adding the reinforcement powder to the polished base alloy block and pressing it into a block comprises:

[0015] The mass fractions of Ti6Al4V alloy block, reinforcement C powder and reinforcement TiB2 powder are 97.43%, 0.69% and 1.88%, respectively. Subsequently, the reinforcement C powder and the reinforcement TiB2 powder are mechanically mixed at 200 rpm for 2 hours using a powder mixer, and then pressed into a block with the matrix Ti6Al4V alloy.

[0016] Furthermore, in step 1, adding the reinforcement powder to the polished base alloy block and pressing it into a block comprises:

[0017] The mass fractions of Ti6Al4V alloy block, reinforcement C powder and Si powder are 98.54%, 0.71% and 0.75%, respectively. Subsequently, the reinforcement C powder and the reinforcement Si powder are mechanically mixed at 200 rpm for 2 hours using a powder mixer, and then pressed into a block with the matrix Ti6Al4V alloy.

[0018] Furthermore, in step 2, melting the block into a titanium-based composite material ingot using a vacuum non-consumable arc furnace comprises:

[0019] First, clean the furnace of the electric arc furnace: use argon gas to wash the furnace of the electric arc furnace three times to minimize gas impurities such as oxygen, nitrogen, and hydrogen during the smelting process and reduce pollution sources. Then, vacuum the electric arc furnace to a vacuum degree of 1×10 -4 ~1×10 -5 Pa;

[0020] The block is placed on a water-cooled copper crucible in a vacuum non-consumable electric arc furnace, the door of the electric arc furnace is closed, and smelting is performed to obtain an ingot.

[0021] Furthermore, the smelting block parameters include:

[0022] The melting current was set to 1-3.5 kA, and the melting times were ≥5 times, among which the melting was performed once after flipping, and finally a titanium-based composite material ingot was obtained.

[0023] Furthermore, the step 3 includes:

[0024] First, the titanium-based composite material ingot is placed on an ultrasonic atomization table. The input heat source is the plasma generated by an arc melter, the current is 215A, and the melting temperature is above 1400°C. The ultrasonic frequency is set to 40kHz, the amplitude displacement is 100%, and the argon flow rate is set to 10NL / min, and finally the titanium-based composite material powder is obtained.

[0025] The technical solution adopted by the present invention has the following beneficial effects:

[0026] In the present application, the reinforcement powder is mixed with the matrix Ti6Al4V alloy in a corresponding mass ratio and pressed into a block, which is then placed in a water-cooled copper crucible in the furnace of a vacuum non-consumable arc furnace for arc melting. The reinforcement phase is directly generated by the in-situ autogenous reaction between the matrix alloy and the reinforcement to prepare a particle-reinforced Ti6Al4V-based composite ingot. The ingot is then placed on an ultrasonic atomization table and melted using an arc melter. The titanium-based composite ingot is then atomized into fine droplets under the action of ultrasound and solidified into metal powder during the outward spraying process. The titanium-based composite powder prepared by the embedded reinforcement preparation method has the advantages of high sphericity, no pores or broken particles, and a smooth surface without satellite balls. It solves the problems of irregular powder shape, rough surface, poor fluidity, wide particle size distribution, uneven reinforcement distribution and inconsistent powder properties existing in titanium-based composite powder prepared by traditional mechanical mixing or gas atomization methods. Therefore, ultrasonic atomization powder making technology can not only effectively prepare titanium-based composite material powder, but also the powder can be used as high-quality raw material in additive manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A flow chart for preparing powder of a nano-particle hybrid reinforced titanium-based composite material provided by the present invention;

[0028] Figure 2 The technical route of the method for manufacturing nano-particle hybrid reinforced titanium-based composite material powder provided by the present invention and the scanning electron microscope image of the spherical powder;

[0029] Figure 3 This is a scanning electron microscope image of the powder cross section of a nano-particle hybrid reinforced titanium-based composite material powder provided by the present invention. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0031] In the first aspect, in this embodiment, the present invention provides a nano-particle hybrid reinforced titanium-based composite material powder, which has the advantages of high sphericity, no pores or broken particles, and a smooth surface without satellite balls, and can be used as a high-quality titanium-based composite material powder raw material in additive manufacturing; wherein, please refer to Figure 1 The preparation method of nano-particle hybrid reinforced titanium-based composite material powder is as follows:

[0032] Example 1

[0033] Preparation of ingot raw materials

[0034] In order to improve the quality of the ingot after smelting, the surface of the Ti6Al4V alloy block is first polished with sandpaper to remove the surface oxide layer and impurities, thereby reducing inclusions during the smelting process and ensuring the purity and uniformity of the ingot.

[0035] The mass fractions of Ti6Al4V, reinforcement Si powder and TiB2 powder added to prepare titanium-based composite ingots are 95.85%, 2.19% and 1.96%, respectively. Subsequently, the reinforcement Si powder and the reinforcement TiB2 powder are mechanically mixed at 200 rpm for 2 hours using a powder mixer and then pressed into blocks with the matrix Ti6Al4V alloy. The purpose of powder mixing is to mix the reinforcement powders evenly and distribute them evenly on the matrix Ti6Al4V alloy after being pressed into blocks, so as to ensure that the reinforcements are evenly distributed in the organization during the subsequent smelting process, avoid segregation during the smelting process, and improve the uniformity and consistency of the titanium-based composite ingots.

[0036] The pressed block is then placed on a water-cooled copper crucible in a vacuum non-consumable electric arc furnace, and the furnace door is closed. In order to produce high-purity, low-impurity titanium-based composite materials, the furnace chamber of the electric arc furnace is purged three times with argon gas to minimize gas impurities such as oxygen, nitrogen, and hydrogen during the smelting process, reduce pollution sources, and ensure high purity of the ingot. The electric arc furnace is then evacuated to a vacuum degree of 1×10 -4 ~1×10 -5 Pa. A vacuum degree lower than this value range may result in gas contamination of the ingot, increased porosity and decreased surface quality.

[0037] In order to ensure the full melting of the matrix alloy and the reinforcement powder and the complete in-situ autogenous reaction, the melting current is 1~3.5kA. At the same time, in order to ensure the uniformity and melting quality of the smelting ingot, the melting times are ≥5 times (including one melting after the ingot is turned over), and finally a titanium-based composite ingot is obtained.

[0038] Ultrasonic atomization powder making;

[0039] The entire powder-making process is completed in a stainless steel vacuum chamber. First, a titanium-based composite ingot is placed on an ultrasonic atomization table. The heat source is plasma generated by an arc melter, with a current of 215A and a melting temperature of 1400°C. Temperatures below this limit prevent the ingot from fully melting, affecting the melt's fluidity and surface tension, and consequently, the powder particle size, distribution, powder-making efficiency, and yield.

[0040] Since different ultrasonic frequencies and amplitude displacements can have a significant impact on the yields of different powder particle size ranges, in order to prepare the powder with the highest yield in the target particle size range (50-100 μm) and promote melt breakage and atomization to improve atomization efficiency, the ultrasonic frequency was set to 40 kHz and the amplitude displacement was set to 100%.

[0041] To promote the condensation of tiny droplets generated by melt atomization into powder, while ensuring efficient collection of the powder and preventing its oxidation, the argon flow rate was set at 10 NL / min. The final powder particle size distribution, yield, and sphericity are shown in the table below.

[0042]

[0043] Example 2

[0044] Preparation of ingot raw materials

[0045] In order to improve the quality of the ingot after smelting, the surface of the Ti6Al4V alloy block is first polished with sandpaper to remove the surface oxide layer and impurities, thereby reducing inclusions during the smelting process and ensuring the purity and uniformity of the ingot.

[0046] The mass fractions of Ti6Al4V, reinforcement C powder and reinforcement TiB2 powder added to prepare titanium-based composite ingots are 97.43%, 0.69% and 1.88%, respectively. Subsequently, the reinforcement C powder and the reinforcement TiB2 powder are mechanically mixed at 200 rpm for 2 hours using a powder mixer and then pressed into blocks with the matrix Ti6Al4V alloy. The purpose of powder mixing is to mix the reinforcement powders evenly and distribute them evenly on the matrix Ti6Al4V alloy after being pressed into blocks, so as to ensure that the reinforcements are evenly distributed in the organization during the subsequent smelting process, avoid segregation during the smelting process, and improve the uniformity and consistency of the titanium-based composite ingots.

[0047] The pressed block is then placed on a water-cooled copper crucible in a vacuum non-consumable electric arc furnace, and the furnace door is closed. In order to produce high-purity, low-impurity titanium-based composite materials, the furnace chamber of the electric arc furnace is purged three times with argon gas to minimize gas impurities such as oxygen, nitrogen, and hydrogen during the smelting process, reduce pollution sources, and ensure high purity of the ingot. The electric arc furnace is then evacuated to a vacuum degree of 1×10 -4 ~1×10 -5 Pa. A vacuum degree lower than this value range may result in gas contamination of the ingot, increased porosity and decreased surface quality.

[0048] In order to ensure the full melting of the matrix alloy and the reinforcement powder and the complete in-situ autogenous reaction, the melting current is 1~3.5kA. At the same time, in order to ensure the uniformity and melting quality of the smelting ingot, the melting times are ≥5 times (including one melting after the ingot is turned over), and finally a titanium-based composite ingot is obtained.

[0049] Ultrasonic atomization powder making

[0050] The entire powder-making process is completed in a stainless steel vacuum chamber. First, a titanium-based composite ingot is placed on an ultrasonic atomization table. The heat source is plasma generated by an arc melter, with a current of 215A and a melting temperature of 1400°C. Temperatures below this limit prevent the ingot from fully melting, affecting the melt's fluidity and surface tension, and consequently, the powder particle size, distribution, powder-making efficiency, and yield.

[0051] Because different ultrasonic frequencies and amplitude displacements significantly affect powder yields in different particle size ranges, the ultrasonic frequency was set to 40 kHz and the amplitude displacement to 100% to maximize yield within the target particle size range (50-100 μm) and promote melt breakup and atomization, thereby improving atomization efficiency. To promote condensation of the tiny droplets produced by melt atomization into powder while ensuring efficient powder collection and preventing oxidation, the argon flow rate was set to 10 nL / min. The final powder particle size distribution, yield, and sphericity are shown in the table below.

[0052]

[0053] Example 3

[0054] Preparation of ingot raw materials

[0055] To improve the quality of the ingot after smelting, the surface of the Ti6Al4V alloy block was first polished with sandpaper to remove the surface oxide layer and impurities, thereby reducing inclusions during the smelting process and ensuring the purity and uniformity of the ingot. The mass fractions of Ti6Al4V, reinforcement C powder, and Si powder added to prepare the titanium-based composite ingot were 98.54%, 0.71%, and 0.75%, respectively. Subsequently, the reinforcement C powder and reinforcement Si powder were mechanically mixed at 200 rpm for 2 hours and then pressed into a block with the matrix Ti6Al4V alloy. The purpose of the powder mixing is to ensure that the reinforcement powder is evenly mixed and evenly distributed on the matrix Ti6Al4V alloy after being pressed into a block. This ensures that the reinforcement is evenly distributed in the microstructure during the subsequent smelting process, avoids segregation during the smelting process, and improves the uniformity and consistency of the titanium-based composite ingot.

[0056] The pressed block is then placed on a water-cooled copper crucible in a vacuum non-consumable electric arc furnace, and the furnace door is closed. To produce a high-purity, low-impurity titanium-based composite material, the furnace chamber is purged three times with argon gas. This minimizes gaseous impurities such as oxygen, nitrogen, and hydrogen during the smelting process, reduces pollution sources, and ensures the high purity of the ingot.

[0057] Then the arc furnace is vacuumed to a vacuum degree of 1×10 -4 ~1×10 -5 Pa. A vacuum degree lower than this value range may cause gas contamination of the ingot, increased porosity, and decreased surface quality. In order to ensure the full melting of the matrix alloy and reinforcement powder and the complete in-situ autogenous reaction, the melting current is 1~3.5kA. At the same time, in order to ensure the uniformity and melting quality of the smelting ingot, the melting number is ≥5 times (including one melting after the ingot is turned over), and finally a titanium-based composite ingot is obtained.

[0058] Ultrasonic atomization powder making

[0059] The entire powder-making process is completed in a stainless steel vacuum chamber. First, a titanium-based composite ingot is placed on an ultrasonic atomization table. The heat source is plasma generated by an arc melter, with a current of 215A and a melting temperature of 1400°C. Temperatures below this limit prevent the ingot from fully melting, affecting the melt's fluidity and surface tension, and consequently, the powder particle size, distribution, powder-making efficiency, and yield.

[0060] Because different ultrasonic frequencies and amplitude displacements significantly affect powder yields in different particle size ranges, the ultrasonic frequency was set to 40 kHz and the amplitude displacement to 100% to maximize yield within the target particle size range (50-100 μm) and promote melt breakup and atomization, thereby improving atomization efficiency. To promote condensation of the tiny droplets produced by melt atomization into powder while ensuring efficient powder collection and preventing oxidation, the argon flow rate was set to 10 nL / min. The final powder particle size distribution, yield, and sphericity are shown in the table below.

[0061]

[0062] In this example, see Figure 2The present invention aims to provide a high-quality embedded uniformly distributed nano-particle hybrid reinforced titanium-based composite material powder for additive manufacturing and a preparation method thereof. The powder of the reinforcement body is mixed in a corresponding mass ratio and then pressed into a block with a matrix Ti6Al4V alloy. The block is then placed in a water-cooled copper crucible in the hearth of a vacuum non-consumable arc furnace for arc melting. The reinforcement phase is directly generated by an in-situ autogenous reaction between the matrix alloy and the reinforcement body to prepare a particle-reinforced Ti6Al4V-based composite material ingot. The ingot is then placed on an ultrasonic atomization table and melted by an arc melter. The titanium-based composite material ingot is then atomized into fine droplets under the action of ultrasound and solidified into metal powder during the outward spraying process.

[0063] See also Figure 3 , Figure 3 The scanning electron microscope image of the powder cross section is shown in the figure. It can be seen that the reinforcement is evenly distributed in the powder structure of the titanium-based composite material prepared by the embedded reinforcement preparation method, and there is no cracking or shrinkage cavity inside the particles.

[0064] The titanium-based composite powder produced using the embedded reinforcement preparation method in this invention exhibits high sphericity, no porosity or broken particles, and a smooth surface free of satellites. This overcomes the problems of irregular powder shape, rough surface, poor flowability, wide particle size distribution, uneven reinforcement distribution, and inconsistent powder properties often encountered in titanium-based composite powders produced using traditional mechanical mixing or aerosolization methods. Therefore, ultrasonic atomization powder production technology not only effectively produces titanium-based composite powders, but also allows the powder to serve as a high-quality raw material for additive manufacturing.

[0065] Other embodiments of the present invention will readily occur to those skilled in the art after considering the specification and practicing the embodiments disclosed herein. The present invention is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the invention being indicated by the claims.

Claims

1. A method for preparing nano-particle hybrid reinforced titanium-based composite material powder, characterized in that: include: Step 1: grinding the base alloy block, mixing multiple reinforcement powders by mechanical mixing, adding them to the ground base alloy block, and pressing them into a block; In step 1, the base alloy block is a Ti6Al4V alloy block, and the surface of the Ti6Al4V alloy block is polished with sandpaper to remove the surface oxide layer and impurities; In step 1, adding a plurality of reinforcement powders to the polished base alloy block and pressing the block into a block comprises: The mass fractions of Ti6Al4V alloy block, reinforcement Si powder and TiB2 powder were 95.85%, 2.19% and 1.96%, respectively. The reinforcement Si powder and the reinforcement TiB2 powder were then mechanically mixed at 200 rpm for 2 h in a powder mixer and then pressed into blocks with the matrix Ti6Al4V alloy. Step 2: melting the block into a titanium-based composite ingot in a vacuum non-consumable arc furnace; Step 3: Powdering the titanium-based composite material ingot by ultrasonic atomization to obtain titanium-based composite material powder; In step 3, the titanium-based composite material ingot is first placed on an ultrasonic atomization table, the input heat source is the plasma generated by the arc melter, the current is 215A, and the melting temperature is above 1400°C; the ultrasonic frequency is set to 40kHz, the amplitude displacement is 100%; the argon flow rate is set to 10NL / min, and finally the titanium-based composite material powder is obtained.

2. The method for preparing nano-particle hybrid reinforced titanium-based composite material powder according to claim 1, characterized in that: In step 1, adding a plurality of reinforcement powders to the polished base alloy block and pressing the block into a block comprises: The mass fractions of Ti6Al4V alloy block, reinforcement C powder and reinforcement TiB2 powder are 97.43%, 0.69% and 1.88%, respectively. Subsequently, the reinforcement C powder and the reinforcement TiB2 powder are mechanically mixed at 200 rpm for 2 hours using a powder mixer, and then pressed into a block with the matrix Ti6Al4V alloy.

3. The method for preparing nano-particle hybrid reinforced titanium-based composite material powder according to claim 1, characterized in that: In step 1, adding a plurality of reinforcement powders to the polished base alloy block and pressing the block into a block comprises: The mass fractions of Ti6Al4V alloy block, reinforcement C powder and Si powder are 98.54%, 0.71% and 0.75%, respectively. Subsequently, the reinforcement C powder and the reinforcement Si powder are mechanically mixed at 200 rpm for 2 hours using a powder mixer, and then pressed into a block with the matrix Ti6Al4V alloy.

4. The method for preparing nano-particle hybrid reinforced titanium-based composite material powder according to claim 1, characterized in that: In step 2, the block is melted into a titanium-based composite material ingot using a vacuum non-consumable arc furnace, which includes: First, clean the furnace of the electric arc furnace: use argon gas to wash the furnace of the electric arc furnace three times to minimize gas impurities such as oxygen, nitrogen, and hydrogen during the smelting process and reduce pollution sources. Then, vacuum the electric arc furnace to a vacuum degree of 1×10 -4 ~1×10 -5 Pa; The block is placed on a water-cooled copper crucible in a vacuum non-consumable electric arc furnace, the door of the electric arc furnace is closed, and smelting is performed to obtain an ingot.

5. The method for preparing nano-particle hybrid reinforced titanium-based composite material powder according to claim 4, characterized in that: Melt block parameters include: The melting current was set to 1-3.5 kA, and the melting times were ≥5 times, among which the melting was performed once after flipping, and finally a titanium-based composite material ingot was obtained.

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