Micro-nano dual-scale particle reinforced titanium matrix composite material and preparation method thereof

Abstract

The application discloses a kind of micro-nano dual-scale particle reinforced titanium matrix composite and preparation method thereof, micro-nano dual-scale particle reinforced titanium matrix composite ingot is obtained by smelting, first, after cutting, micro-nano dual-scale particle reinforced titanium matrix composite ingot is solid solution heat treated, solid solution temperature is 1150 DEG C, solid solution time is 30 min;Micro-nano dual-scale particle reinforced titanium matrix composite ingot in solid solution state is water quenched, after sample is cooled to room temperature;Finally, aging heat treatment is carried out at 800 DEG C for 5h, after aging, air cooling is cooled to room temperature, and finally, micro-nano dual-scale particle reinforced titanium matrix composite is obtained.Compared with prior art, by solid solution aging heat treatment in sequence to micro-nano dual-scale particle reinforced titanium matrix composite ingot, the purpose that the size and distribution of Ti5Si3 particle can be effectively controlled without overburning phenomenon of composite material can be achieved, and finally, the mechanical properties of titanium matrix composite are improved.

Description

Technical Field

[0001] This invention relates to the field of titanium-based composite materials, and in particular to a micro / nano dual-scale particle-reinforced titanium-based composite material and its preparation method. Background Technology

[0002] Discontinuous particle-reinforced titanium matrix composites (DRTMCs) are considered one of the most promising candidate structural materials in high-tech fields such as automotive and aerospace due to their low density, high specific strength, good wear resistance, and excellent high-temperature performance. Traditional single-phase homogenized composite preparations of titanium matrix composites mainly focus on controlling the compatibility and distribution uniformity of the reinforcing phase with the interface. However, while introducing reinforcing phases such as particles, whiskers, and fibers improves strength and wear resistance, localized stress concentration and deformation mismatch between the reinforcing phase and the titanium matrix lead to a strength-toughness inversion problem. To address this strength-toughness inversion issue in traditional single-phase homogenized composite preparations of titanium matrix composites, emulating the multi-dimensional, multi-scale design of biomaterials in nature can enable materials to achieve excellent comprehensive properties. In ceramic-reinforced titanium matrix composites, reinforcing phases of different scales distributed at different levels can effectively improve the strength-toughness inversion phenomenon.

[0003] Heat treatment is considered one of the effective ways to optimize the properties of composite materials by regulating their phase transformation behavior and microstructure. Solution treatment (ST) aims to re-dissolve Si, rapid cooling via hardening (WQ) is used to suppress silicide precipitation, and air cooling (AC) after aging is used to induce the precipitation of the Ti5Si3 phase. Thus, heat treatment is used to control the distribution and size of Ti5Si3. The solution-quenching process is accompanied by allotropic transformations and martensitic transformations, resulting in a β-transformation microstructure (β...). T The primary α phase appears as coarse plates and is relatively large in size. However, the β phase... T It mainly consists of acicular martensitic α' phase and metastable β phase, or fine α and β phases. The aging heat treatment process decomposes the metastable β phase formed during solution heat treatment, resulting in smaller lamellar and strip-like secondary α phases. The morphology and size of the secondary α phase precipitated during aging heat treatment depend on the microstructure formed by solution heat treatment and the aging temperature. The higher the content or the worse the stability of the metastable β phase formed by solution heat treatment, the better the strengthening effect. After solution and aging heat treatment, titanium-based composite materials can obtain a metastable β phase and dispersed α phase, thereby further improving the mechanical properties of the material. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a micro / nano dual-scale particle-reinforced titanium-based composite material and its preparation method.

[0005] To achieve the above objectives, the present invention is implemented according to the following technical solution:

[0006] One objective of this invention is to provide a method for preparing micro / nano dual-scale particle-reinforced titanium-based composite materials, comprising the following steps:

[0007] S1. Using industrial-grade TC4 titanium alloy, C powder, and Si powder as raw materials, a vacuum non-consumable arc furnace was used for melting to obtain a cast titanium-based composite material. The mass percentages of each component in the cast titanium-based composite material were determined as follows: Si: 0.798–0.823 wt.%, C: 0.728–1.131 wt.%, Al: 5.628–6.382 wt.%, V: 3.726–4.451 wt.%, with the balance being Ti. Then, the cast titanium-based composite material was repeatedly melted on both sides 5–6 times to obtain a micro / nano dual-scale particle-reinforced titanium-based composite material ingot.

[0008] S2. Cut the obtained micro / nano dual-scale particle-reinforced titanium matrix composite ingot;

[0009] S3. First, the cut micro-nano dual-scale particle reinforced titanium matrix composite ingot is subjected to solution heat treatment at a temperature of 1150℃ for 30 minutes. Then, the solution-treated micro-nano dual-scale particle reinforced titanium matrix composite ingot is water-quenched until the sample cools to room temperature.

[0010] S4. Finally, the material is subjected to aging heat treatment at 800℃ for 5 hours, followed by air cooling to room temperature to obtain a micro / nano dual-scale particle-reinforced titanium matrix composite material.

[0011] Preferably, the purity of the C powder is 99.8% and the average particle size is 100 nm.

[0012] Preferably, the purity of the Si powder is 99% and the average particle size is 800 nm.

[0013] The second objective of this invention is to provide a micro / nano dual-scale particle reinforced titanium matrix composite material prepared by the above preparation method. This micro / nano dual-scale particle reinforced titanium matrix composite material is a (3 vol.% TiC + 3 vol.% Ti5Si3) / TC4 composite material with a compressive strength ≥1850 MPa and a compressive plasticity ≥26.79%.

[0014] The principle of this invention is as follows: the purpose of the solution treatment is to re-dissolve the Si element; the rapid cooling by quenching is to suppress the precipitation of silicides; and the air cooling after aging is to allow the Ti5Si3 phase to precipitate, thereby controlling the distribution and size of Ti5Si3 through heat treatment; the solution quenching process is accompanied by allotropic transformation and martensitic transformation, resulting in a β-transformation microstructure (β... T The primary α phase appears as coarse plates and is relatively large in size; however, the β phase... TIt mainly contains acicular martensitic α' phase and metastable β phase or fine α and β phase; after solution quenching at 1150℃, most of the Si element is dissolved back into the matrix, and the Ti5Si3 particles are completely dissolved.

[0015] Compared with existing technologies, this invention, by sequentially performing solution-aging heat treatment on micro / nano dual-scale particle-reinforced titanium matrix composite ingots, can effectively control the size and distribution of Ti5Si3 particles without overheating, ultimately improving the mechanical properties of the titanium matrix composite. Compared with existing (TiB+TiC) / Ti-based composites, this invention reduces costs, achieves effective control of the reinforcing phase through heat treatment, and obtains titanium matrix composites with a wider controllability range and higher overall mechanical properties. Attached Figure Description

[0016] Figure 1 Microstructure of cast titanium-based composite materials.

[0017] Figure 2 Microstructure of solid solution titanium-based composite material (1150℃ / 30min / WQ).

[0018] Figure 3 Microstructure of aged (800℃ / 5h / AC) titanium-based composite material.

[0019] Figure 4 XRD pattern of heat-treated titanium-based composite material.

[0020] Figure 5 Room temperature compression performance curves of heat-treated titanium-based composite materials.

[0021] Figure 6 Microstructure of aged (700℃ / 5h / AC) titanium-based composite material.

[0022] Figure 7 Microstructure of aged (900℃ / 5h / AC) titanium-based composite material. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. The specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention.

[0024] Example 1

[0025] 1) Industrial-grade TC4 titanium alloy, C powder (99.8% purity, average particle size 100nm), and Si powder (99% purity, average particle size 800nm) were selected as raw materials. A vacuum non-consumable arc furnace was used for melting. The experimental materials were placed separately in water-cooled copper crucibles. The carbon powder and silicon powder were wrapped in aluminum foil to prevent splashing during melting. A cast titanium-based composite material was obtained, and the mass percentage of each component in the cast titanium-based composite material was determined as follows: Si: 0.79 The composition was 8–0.823 wt.%, C: 0.728–1.131 wt.%, Al: 5.628–6.382 wt.%, V: 3.726–4.451 wt.%, with the balance being Ti. The cast titanium matrix composite was then subjected to 5–6 repeated melting processes on both sides to obtain a micro / nano dual-scale particle-reinforced titanium matrix composite ingot. SEM was used to observe the microstructure of the ingot, revealing a uniform distribution of the reinforcing phase without significant aggregation. Figure 1 As shown.

[0026] 2) A cylindrical rod with a diameter of 4 mm and a height of 6 mm was cut from the center of the micro-nano dual-scale particle-reinforced titanium matrix composite ingot;

[0027] 3) First, the cylindrical rod was subjected to solution heat treatment at 1150℃ for 30 minutes; the solution-treated micro / nano dual-scale particle-reinforced titanium matrix composite ingot was then water-quenched until the sample cooled to room temperature; the microstructure of the solution-treated state was then observed using SEM. Figure 2 As shown, by Figure 2 It can be seen that after the composite material was subjected to solution treatment at 1150℃ / 30min / WQ, no obvious overheating phenomenon was observed in the microstructure, and most of the Si elements were dissolved back into the matrix, the Ti5Si3 particles were completely dissolved, and some dendritic TiC melted.

[0028] 4) Finally, the material is subjected to aging heat treatment at 800℃ for 5 hours, and then air-cooled to room temperature to obtain the micro-nano dual-scale particle reinforced titanium matrix composite material, namely (3 vol.% TiC + 3 vol.% Ti5Si3) / TC4 composite material.

[0029] The microstructure of the (3 vol.% TiC + 3 vol.% Ti5Si3) / TC4 composite material was observed using SEM (scanning electron microscopy). Figure 3 As shown, by Figure 3 It can be seen that after the composite material is aged at 800℃ for 5 hours, Ti5Si3 particles gradually precipitate at the α / β interface and gradually form a spherical distribution.

[0030] Phase analysis of the (3 vol.% TiC + 3 vol.% Ti5Si3) / TC4 composite material was performed using X-ray diffraction. Figure 4 As shown, after solution treatment and aging, the diffraction peaks of the Ti5Si3 phase in the composite material shifted, indicating that the dissolution of Si caused lattice distortion.

[0031] The (3 vol.% TiC + 3 vol.% Ti5Si3) / TC4 composite material was processed into standard specimens according to the national standard GB / T228.1-2010, and then subjected to room temperature compression testing on an MTS810 electronic universal testing machine with a compressive strain rate of 1.38 × 10⁻⁶. - 4 s -1 The room temperature compressive strength is 1850 MPa, the compressive plasticity is 26.79%, and the room temperature compression test performance is as follows: Figure 5 As shown.

[0032] Comparative Example 1

[0033] 1) Industrial-grade TC4 titanium alloy, C powder (99.8% purity, average particle size 100nm), and Si powder (99% purity, average particle size 800nm) were selected as raw materials. A vacuum non-consumable arc furnace was used for melting. The experimental materials were placed separately in water-cooled copper crucibles. The carbon powder and silicon powder were wrapped in aluminum foil to prevent splashing during melting. A cast titanium-based composite material was obtained, and the mass percentage of each component in the cast titanium-based composite material was determined as follows: Si: 0.79 The composition was 8–0.823 wt.%, C: 0.728–1.131 wt.%, Al: 5.628–6.382 wt.%, V: 3.726–4.451 wt.%, with the balance being Ti. The cast titanium matrix composite was then subjected to 5–6 repeated melting processes on both sides to obtain a micro / nano dual-scale particle-reinforced titanium matrix composite ingot. SEM was used to observe the microstructure of the ingot, revealing a uniform distribution of the reinforcing phase without significant aggregation. Figure 1 As shown.

[0034] 2) A cylindrical rod with a diameter of 4 mm and a height of 6 mm was cut from the center of the micro-nano dual-scale particle-reinforced titanium matrix composite ingot;

[0035] 3) First, the cylindrical bar is subjected to solution heat treatment at a temperature of 1150℃ for 30 minutes; the solution-treated micro-nano dual-scale particle-reinforced titanium matrix composite ingot is then water-quenched until the sample cools to room temperature.

[0036] 4) Finally, the material is subjected to aging heat treatment at 700℃ for 5 hours. After aging, it is cooled to room temperature by air cooling to obtain the micro-nano dual-scale particle reinforced titanium matrix composite material, namely (3 vol.% TiC + 3 vol.% Ti5Si3) / TC4 composite material.

[0037] The microstructure of the (3 vol.% TiC + 3 vol.% Ti5Si3) / TC4 composite material was observed using SEM (scanning electron microscopy). Figure 6 As shown, the number of precipitated Ti5Si3 particles is small and their distribution is uneven, indicating that the aging precipitation effect of Ti5Si3 is not obvious.

[0038] The experimental standards, sample dimensions, and experimental equipment used were exactly the same as those in the room temperature compression test of the example. Specifically, the room temperature compressive strength was 1690 MPa, the compressive plasticity was 20.76%, and the room temperature compression test performance was as follows: Figure 5 As shown, the compressive properties are improved compared to the solid solution composite material, but the compressive properties are lower than those of Example 1, and are not as good as those of Example 1.

[0039] Comparative Example 2

[0040] 1) Industrial-grade TC4 titanium alloy, C powder (99.8% purity, average particle size 100nm), and Si powder (99% purity, average particle size 800nm) were selected as raw materials. A vacuum non-consumable arc furnace was used for melting. The experimental materials were placed separately in water-cooled copper crucibles. The carbon powder and silicon powder were wrapped in aluminum foil to prevent splashing during melting. A cast titanium-based composite material was obtained, and the mass percentage of each component in the cast titanium-based composite material was determined as follows: Si: 0.79 The composition was 8–0.823 wt.%, C: 0.728–1.131 wt.%, Al: 5.628–6.382 wt.%, V: 3.726–4.451 wt.%, with the balance being Ti. The cast titanium matrix composite was then subjected to 5–6 repeated melting processes on both sides to obtain a micro / nano dual-scale particle-reinforced titanium matrix composite ingot. SEM was used to observe the microstructure of the ingot, revealing a uniform distribution of the reinforcing phase without significant aggregation. Figure 1 As shown.

[0041] 2) A cylindrical rod with a diameter of 4 mm and a height of 6 mm was cut from the center of the micro-nano dual-scale particle-reinforced titanium matrix composite ingot;

[0042] 3) First, the cylindrical bar is subjected to solution heat treatment at a temperature of 1150℃ for 30 minutes; the solution-treated micro-nano dual-scale particle-reinforced titanium matrix composite ingot is then water-quenched until the sample cools to room temperature.

[0043] 4) Finally, the material is subjected to aging heat treatment at 900℃ for 5 hours. After aging, it is cooled to room temperature by air cooling to obtain the micro-nano dual-scale particle reinforced titanium matrix composite material, namely (3 vol.% TiC + 3 vol.% Ti5Si3) / TC4 composite material.

[0044] The microstructure of the (3 vol.% TiC + 3 vol.% Ti5Si3) / TC4 composite material was observed using SEM (scanning electron microscopy). Figure 7 As shown, the precipitated Ti5Si3 particles are relatively large in size and fewer in number, indicating poor aging precipitation of Ti5Si3. The excessively high aging temperature leads to the growth of Ti5Si3 particles.

[0045] The experimental standards, sample dimensions, and experimental equipment used were exactly the same as those in the room temperature compression test of the example. Specifically, the room temperature compressive strength was 1740 MPa, the compressive plasticity was 24.85%, and the room temperature compression test performance was as follows: Figure 5 As shown, the compressive properties are improved compared to the solid solution composite material, but the compressive properties are lower than those of Example 1, and are not as good as those of Example 1.

[0046] In summary, this invention provides a solution-aging heat treatment process for a micro / nano dual-scale (3 vol.% TiC + 3 vol.% Ti5Si3) / TC4 composite material: 1150℃ / 30min / WQ + 800℃ / 5h / AC. Using this process, the size and distribution of Ti5Si3 particles can be effectively controlled without overheating, ultimately improving the mechanical properties of the titanium-based composite material. Specifically, the room temperature compressive strength reaches 1850 MPa, and the compressive plasticity reaches 26.79%.

[0047] The technical solutions of the present invention are not limited to the specific embodiments described above. Any technical modifications made in accordance with the technical solutions of the present invention fall within the protection scope of the present invention.

Claims

1. A method for preparing a micro / nano dual-scale particle-reinforced titanium-based composite material, characterized in that, Includes the following steps: S1. Using industrial-grade TC4 titanium alloy, C powder, and Si powder as raw materials, a vacuum non-consumable arc furnace was used for melting to obtain a cast titanium-based composite material. The mass percentages of each component in the cast titanium-based composite material were determined as follows: Si: 0.798–0.823 wt.%, C: 0.728–1.131 wt.%, Al: 5.628–6.382 wt.%, V: 3.726–4.451 wt.%, with the balance being Ti. Then, the cast titanium-based composite material was repeatedly melted on both sides 5–6 times to obtain a micro / nano dual-scale particle-reinforced titanium-based composite material ingot. S2. Cut the obtained micro / nano dual-scale particle-reinforced titanium matrix composite ingot; S3. First, the cut micro-nano dual-scale particle reinforced titanium matrix composite ingot is subjected to solution heat treatment at a temperature of 1150℃ for 30 minutes. Then, the solution-treated micro-nano dual-scale particle reinforced titanium matrix composite ingot is water-quenched until the sample cools to room temperature. S4. Finally, the material is subjected to aging heat treatment at 800℃ for 5 hours, followed by air cooling to room temperature to obtain a micro / nano dual-scale particle-reinforced titanium matrix composite material.

2. The method for preparing micro / nano dual-scale particle-reinforced titanium-based composite materials according to claim 1, characterized in that: The purity of the C powder is 99.8%, and the average particle size is 100 nm.

3. The method for preparing micro / nano dual-scale particle-reinforced titanium-based composite materials according to claim 1, characterized in that: The Si powder has a purity of 99% and an average particle size of 800 nm.

4. A micro / nano dual-scale particle-reinforced titanium-based composite material prepared by the preparation method according to any one of claims 1-3.

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