阅读说明：本技术 一种磷化硼填充铝基热管理材料及其制备方法 (Boron phosphide-filled aluminum-based heat management material and preparation method thereof ) 是由 夏鸿雁 杨婷 汪胜和 胡佳军 王凯 侯鑫广 史忠旗 王继平 于 2020-12-25 设计创作，主要内容包括：本发明公开了一种磷化硼填充铝基热管理材料及其制备方法,所述制备方法包括以下步骤：将磷化硼粉和铝粉球磨,获得磷化硼和铝粉混合粉末；将磷化硼和铝粉混合粉末烧结获得磷化硼填充铝基热管理材料。本发明采用磷化硼填充铝材料,其优势在于磷化硼(BP)是一种超硬III-V半导体,为闪锌矿结构,热导率和硬度高,将其作为增强相提高铝基材料的强度。将磷化硼作为增强相加入到纯铝中可以显著提高其硬度。磷化硼具有约490W/m·K的高热导率和较低的密度,具有作为耐火材料和高导热器件的潜力。本发明得到的磷化硼填充铝基热管理材料可应用到导热基板和航空航天等领域。(The invention discloses a boron phosphide-filled aluminum-based heat management material and a preparation method thereof, wherein the preparation method comprises the following steps: ball milling boron phosphide powder and aluminum powder to obtain mixed boron phosphide and aluminum powder; and sintering the mixed powder of boron phosphide and aluminum powder to obtain the boron phosphide-filled aluminum-based thermal management material. The invention adopts the boron phosphide filling aluminum material, has the advantages that Boron Phosphide (BP) is a superhard III-V semiconductor, has a sphalerite structure and high thermal conductivity and hardness, and is used as a reinforcing phase to improve the strength of an aluminum-based material. The hardness of pure aluminum can be obviously improved by adding boron phosphide as a reinforcing phase into the pure aluminum. Boron phosphide has a high thermal conductivity of about 490W/m.k and a relatively low density, and has potential as a refractory material and a high thermal conductive device. The boron phosphide-filled aluminum-based thermal management material obtained by the invention can be applied to the fields of heat-conducting substrates, aerospace and the like.)

1. A preparation method of a boron phosphide-filled aluminum-based heat management material is characterized by comprising the following steps:

ball milling boron phosphide powder and aluminum powder to obtain mixed boron phosphide and aluminum powder;

and sintering the mixed powder of boron phosphide and aluminum powder to obtain the boron phosphide-filled aluminum-based thermal management material.

2. The preparation method of the boron phosphide-filled aluminum-based heat management material as claimed in claim 1, wherein in the step of ball milling the boron phosphide powder and the aluminum powder to obtain the mixed powder of the boron phosphide and the aluminum powder, the mass ratio of the boron phosphide powder to the aluminum powder is 1 (10-50).

3. The method for preparing the boron phosphide-filled aluminum-based heat management material as claimed in claim 1, wherein the step of ball milling boron phosphide powder and aluminum powder to obtain mixed powder of boron phosphide and aluminum powder comprises:

weighing boron phosphide powder and aluminum powder according to the mass ratio of 1 (10-50), adding the weighed raw materials into a ball milling tank, and adding absolute ethyl alcohol and silicon nitride balls; putting the ball milling tank into a planetary ball mill for ball milling;

transferring the ball-milled solution, performing rotary evaporation by using a rotary evaporator, drying at constant temperature, and sieving to obtain boron phosphide and aluminum powder mixed powder.

4. The method for preparing the boron phosphide-filled aluminum-based heat management material as claimed in claim 3, wherein the sieving is performed by a 100-200 mesh sieve.

5. The method for preparing the boron phosphide-filled aluminum-based heat management material as claimed in claim 3, wherein the temperature of rotary evaporation is 50-55 ℃ and the temperature of constant temperature drying is 80 ℃.

6. The method of claim 1, wherein the boron phosphide powder has a particle size of 0.02-100 μm.

7. The method for preparing the boron phosphide-filled aluminum-based heat management material as claimed in claim 1, wherein the aluminum powder is pure aluminum powder or aluminum alloy powder, and the particle size is 1-100 μm.

8. The method of claim 1, wherein the sintering is sintering in a vacuum environment.

9. The method for preparing the boron phosphide-filled aluminum-based heat management material as claimed in claim 1, wherein the sintering temperature is 500 ℃ to 750 ℃ and the sintering time is 5min to 10 min.

10. A boron phosphide-filled aluminum-based thermal management material characterized by being produced by the production method as set forth in any one of claims 1 to 9.

Technical Field

The invention relates to the technical field of heat management materials, in particular to a boron phosphide filled aluminum-based heat management material and a preparation method thereof.

Background

Aluminum metal is considered to be a heat management material with excellent performance because of its high thermal conductivity (200W/m · K) and light weight. However, pure aluminum has low strength and rigidity, and a high thermal conductive ceramic reinforcing phase needs to be added to improve the strength and rigidity of an aluminum matrix. Ceramic reinforcing phases such as AlN, h-BN, SiC, Al have hitherto been used₂O₃CNTs (carbon nanotubes), graphene, and the like have been widely used in aluminum-based materials.

At present, the most studied high thermal conductivity ceramic materials are AlN, h-BN, CNTs, SiC and the like. The theoretical thermal conductivity of AlN single crystal can reach 320W/m · K, but due to inevitable impurity incorporation and defects during sintering, these impurities create various defects in the AlN lattice that reduce the mean degree of freedom of phonons, thereby greatly reducing its thermal conductivity. The AlN ceramic has the defects of long sintering time, high sintering temperature, high manufacturing cost of the AlN ceramic, easy moisture absorption, easy oxidation and the like. The h-BN has low mechanical property, low interlayer thermal conductivity and large thermal expansion coefficient. The theoretical thermal conductivity of SiC is very high and reaches 270W/m.K, and the SiCp/Al composite material is the most researched and widely applied aluminum-based composite material. However, because the ratio of the surface energy to the interfacial energy of SiC ceramic materials is low, i.e., the grain boundary energy is high, a high sintering temperature is required. The wettability of SiC with Al is poor, and therefore, when the volume fraction of SiC particles increases, the mechanical properties of the SiCp/Al composite material deteriorate.

The Carbon fiber or graphite is used as a reinforcement, and the Carbon/Al composite material prepared by compounding with aluminum has better machining performance compared with the SiCp/Al composite material, and can be processed and molded into various complex shapes or thin-wall components. But the mechanical property and the air tightness of the composite material are much poorer than those of SiCp/Al, and particularly, the control of the composite preparation process is improper, so that carbon and aluminum generate chemical reaction to generate a deliquescent brittle product Al₄C₃The composite material is easy to be powdered, and the service durability and reliability are sharply reduced.

Disclosure of Invention

The invention aims to provide a boron phosphide-filled aluminum-based heat management material and a preparation method thereof, and the prepared boron phosphide/aluminum composite material has the following characteristics: high thermal conductivity, high bending strength and high hardness. The boron phosphide-filled aluminum-based heat management material can be used as a heat management material for heat dissipation of military or civil high-power-density electronic devices.

In order to achieve the above purpose, the invention adopts the following technical scheme:

a preparation method of a boron phosphide-filled aluminum-based heat management material comprises the following steps:

ball milling boron phosphide powder and aluminum powder to obtain mixed boron phosphide and aluminum powder;

and sintering the mixed powder of boron phosphide and aluminum powder to obtain the boron phosphide-filled aluminum-based thermal management material.

The invention further improves the following steps: in the step of ball milling the boron phosphide powder and the aluminum powder to obtain the mixed powder of the boron phosphide and the aluminum powder, the mass ratio of the boron phosphide powder to the aluminum powder is 1 (10-50).

The invention further improves the following steps: the method comprises the following steps of ball milling boron phosphide powder and aluminum powder to obtain mixed powder of boron phosphide and aluminum powder, and specifically comprises the following steps:

weighing boron phosphide powder and aluminum powder according to the mass ratio of 1 (10-50), adding the weighed raw materials into a ball milling tank, and adding absolute ethyl alcohol and silicon nitride balls; putting the ball milling tank into a planetary ball mill for ball milling;

transferring the ball-milled solution, performing rotary evaporation by using a rotary evaporator, drying at constant temperature, and sieving to obtain boron phosphide and aluminum powder mixed powder.

The invention further improves the following steps: the sieving is specifically 100-200 mesh sieving.

The invention further improves the following steps: the rotary evaporation temperature is 50-55 deg.C, and the constant temperature drying temperature is 80 deg.C.

The invention further improves the following steps: the particle size of the boron phosphide powder is 0.02-100 mu m.

The invention further improves the following steps: the aluminum powder is pure aluminum powder or aluminum alloy powder, and the particle size is 1-100 mu m.

The invention further improves the following steps: the sintering is sintering in a vacuum environment.

The invention further improves the following steps: the vacuum environment is 0.01-0.1 Mpa.

The invention further improves the following steps: the sintering temperature is 500-750 ℃, and the sintering time is 5-10 min.

The invention further improves the following steps: the method for obtaining the boron phosphide-filled aluminum-based heat management material by sintering the mixed powder of boron phosphide and aluminum powder specifically comprises the following steps:

and (2) sieving the dried boron phosphide and aluminum powder mixed powder through a 100-plus-200-mesh sieve, loading the sieved mixed powder into a graphite mold, putting the graphite mold into a hot-pressing sintering furnace, pressurizing the mold to 20-80MPa, heating the mold to 500-plus-750 ℃ from room temperature under the vacuum condition of 0.01-0.1MPa, preserving heat for 5-10min, sintering, and naturally cooling along with the furnace.

The boron phosphide filled aluminum-based heat management material is prepared by the preparation method.

Compared with the prior art, the invention has the advantages that:

1. the invention adopts the boron phosphide filling aluminum material, has the advantages that Boron Phosphide (BP) is a superhard III-V semiconductor, has a sphalerite structure and high thermal conductivity and hardness, and is used as a reinforcing phase to improve the strength of an aluminum-based material.

2. To date, ceramic reinforcing phases such as SiC, B4C, CNTs (carbon nanotubes), graphene, etc. have been widely used in aluminum-based materials. Early studies found that boron phosphide has a higher hardness than silicon carbide (22GPa), and thus the addition of boron phosphide as a reinforcing phase to pure aluminum significantly increases the hardness.

3. Boron phosphide has a high thermal conductivity of about 490W/m.k and a relatively low density, and has potential as a refractory material and a high thermal conductive device. The boron phosphide-filled aluminum-based thermal management material obtained by the invention can be applied to the fields of heat-conducting substrates, aerospace and the like.

Drawings

FIG. 1 is an XRD pattern of a boron phosphide-filled aluminum-based thermal management material prepared in example 1;

FIG. 2 is an enlarged view of the weak peak of FIG. 1;

FIG. 3 is an EDS spectrum of a boron phosphide-filled aluminum-based thermal management material prepared in example 1.

Detailed Description

BP and¹¹BP has thermal conductivity of 490 and 540W/m.K, which exceeds that of traditional high thermal conductivity materials, such as Ag, Cu, BeO, and SiC. In addition, Boron Phosphide (BP) has not only high thermal conductivity but also low thermal expansion coefficient (3.65X 10)^-6/. degree.C.), low density (2.97 g/cm)³) High hardness (32GPa), high chemical and thermal stability, acid and alkali resistance, oxidation resistance below 1000 ℃ when exposed in air, stability of the compound at 2500 ℃ under high pressure, and the like. According to the invention, boron phosphide is used as a reinforcing phase and added into the aluminum material to improve the strength and rigidity of the aluminum-based material, and simultaneously, the high heat conduction and low thermal expansion performance of the composite material can be ensured.

Example 1

A preparation method of a boron phosphide-filled aluminum-based heat management material comprises the following steps:

(1) weighing prepared boron phosphide powder (with the particle size of 0.02-100 mu m) and aluminum powder (pure aluminum powder or aluminum alloy powder with the particle size of 1-100 mu m) according to the mass ratio of 1:40, adding the weighed raw materials into a ball milling tank, and adding absolute ethyl alcohol and silicon nitride balls with different sizes;

(2) putting the ball milling tank in the step (1) into a planetary ball mill for ball milling, wherein the ball milling rotation speed (revolution) is 200r/min, and the ball milling time is 2 hours;

(3) transferring the ball-milled solution in the step (2) into an eggplant-shaped bottle, performing rotary evaporation by using a rotary evaporation instrument at 50 ℃ for 0.5h, and drying the eggplant-shaped bottle subjected to rotary evaporation at a constant temperature of 80 ℃ for 4 h;

(4) sieving the mixed powder of boron phosphide and aluminum powder obtained by drying in the step (3) by a 200-mesh sieve, loading the sieved mixed powder into a graphite mold, and putting the graphite mold into a hot-pressing sintering furnace, wherein the mold is pressurized to 50 MPa; heating from room temperature to 530 ℃ under the vacuum condition of 0.05MPa, preserving heat for 10min, and then naturally cooling along with the furnace;

(5) and (3) polishing the sintered block by using sand paper, and removing graphite paper on the surface to obtain the boron phosphide-filled aluminum-based heat management material.

The boron phosphide-filled aluminum-based heat management material obtained in the embodiment has the bending strength of 435.3MPa, the Vickers hardness of 40.2HV1/10 and the thermal conductivity of 213.9W/(m × K).

Referring to the XRD pattern of FIG. 1, the sintered mass is shown with BP and Al present. Because of the low content of added BP, the peak of XRD of BP is not obvious, and can refer to the weak peak amplified in figure 2, and 34 degrees is the first strong peak of BP.

Referring to the EDS spectrum of FIG. 3, the sintered block is seen to have P by surface scanning, and O is present because the surface of the aluminum matrix composite is oxidized.

Example 2

A boron phosphide filled aluminum-based heat management material and a preparation method thereof comprise the following steps:

(1) weighing prepared boron phosphide powder (with the particle size of 0.02-100 mu m) and aluminum powder (pure aluminum powder or aluminum alloy powder with the particle size of 1-100 mu m) according to the mass ratio of 1:20, adding the weighed raw materials into a ball milling tank, and adding absolute ethyl alcohol and silicon nitride balls with different sizes;

(2) putting the ball milling tank in the step (1) into a planetary ball mill for ball milling, wherein the ball milling rotation speed (revolution) is 100r/min, and the ball milling time is 1 h;

(3) transferring the ball-milled solution in the step (2) into an eggplant-shaped bottle, performing rotary evaporation by using a rotary evaporation instrument at 50 ℃ for 0.5h, and drying the eggplant-shaped bottle subjected to rotary evaporation at a constant temperature of 80 ℃ for 4 h;

(4) sieving the mixed powder of boron phosphide and aluminum powder obtained by drying in the step (3) by a 200-mesh sieve, filling the sieved mixed powder into a graphite mold, and putting the graphite mold into a hot-pressing sintering furnace, wherein the mold is pressurized to 20 MPa; heating from room temperature to 500 deg.C under vacuum condition of 0.05MPa, maintaining for 8min, and naturally cooling with the furnace;

(5) and (3) polishing the sintered block by using sand paper, and removing graphite paper on the surface to obtain the boron phosphide-filled aluminum-based heat management material.

The boron phosphide-filled aluminum-based heat management material obtained in the embodiment has the bending strength of 335MPa, the Vickers hardness of 45.8HV1/10 and the thermal conductivity of 186W/(m × K).

Example 3

A boron phosphide filled aluminum-based heat management material and a preparation method thereof comprise the following steps:

(1) weighing prepared boron phosphide powder (with the particle size of 0.02-100 mu m) and aluminum powder (pure aluminum powder or aluminum alloy powder with the particle size of 1-100 mu m) according to the mass ratio of 1:50, adding the weighed raw materials into a ball milling tank, and adding absolute ethyl alcohol and silicon nitride balls with different sizes;

(2) putting the ball milling tank in the step (1) into a planetary ball mill for ball milling, wherein the ball milling rotation speed (revolution) is 400r/min, and the ball milling time is 0.5 h;

(3) transferring the ball-milled solution in the step (2) into an eggplant-shaped bottle, performing rotary evaporation by using a rotary evaporation instrument at 55 ℃ for 0.5h, and drying the eggplant-shaped bottle subjected to rotary evaporation at a constant temperature of 80 ℃ for 4 h;

(4) sieving the mixed powder of boron phosphide and aluminum powder obtained by drying in the step (3) by a 200-mesh sieve, filling the sieved mixed powder into a graphite mold, and putting the graphite mold into a hot-pressing sintering furnace, wherein the mold is pressurized to 80 MPa; heating from room temperature to 750 deg.C under vacuum condition of 0.05MPa, maintaining for 5min, and naturally cooling with the furnace;

(5) and (3) polishing the sintered block by using sand paper, and removing graphite paper on the surface to obtain the boron phosphide-filled aluminum-based heat management material.

The boron phosphide-filled aluminum-based heat management material obtained in the example has the bending strength of 297.8MPa, the Vickers hardness of 49HV1/10 and the thermal conductivity of 150W/(m × K).

Example 4

A boron phosphide filled aluminum-based heat management material and a preparation method thereof comprise the following steps:

(1) weighing prepared boron phosphide powder (with the particle size of 0.02-100 mu m) and aluminum powder (pure aluminum powder or aluminum alloy powder with the particle size of 1-100 mu m) according to the mass ratio of 1:10, adding the weighed raw materials into a ball milling tank, and adding absolute ethyl alcohol and silicon nitride balls with different sizes;

(2) putting the ball milling tank in the step (1) into a planetary ball mill for ball milling, wherein the ball milling rotation speed (revolution) is 200r/min, and the ball milling time is 2 hours;

(3) transferring the ball-milled solution in the step (2) into an eggplant-shaped bottle, performing rotary evaporation by using a rotary evaporation instrument at a rotary evaporation temperature of 53 ℃ for 0.5h, and drying the eggplant-shaped bottle subjected to rotary evaporation at a constant temperature of 80 ℃ for 4 h;

(4) sieving the mixed powder of boron phosphide and aluminum powder obtained by drying in the step (3) by a 200-mesh sieve, loading the sieved mixed powder into a graphite mold, and putting the graphite mold into a hot-pressing sintering furnace, wherein the mold is pressurized to 60 MPa; heating from room temperature to 650 ℃ under the vacuum condition of 0.05MPa, preserving heat for 10min, and then naturally cooling along with the furnace;

(5) and (3) polishing the sintered block by using sand paper, and removing graphite paper on the surface to obtain the boron phosphide-filled aluminum-based heat management material.

The boron phosphide-filled aluminum-based heat management material obtained in the example has the bending strength of 281.7MPa, the Vickers hardness of 66.2HV1/10 and the thermal conductivity of 134.3W/(m.K).

The boron phosphide-filled aluminum-based heat management material has the advantages that Boron Phosphide (BP) is a superhard III-V semiconductor, is of a sphalerite structure, has high heat conductivity, low thermal expansion coefficient (3.65 multiplied by 10 < -6 >/DEG C), low density (2.97g/cm3), high hardness (32GPa), good chemical and thermal stability, acid and alkali resistance, can resist oxidation below 1000 ℃ when exposed in air, and can still keep the stability of a compound at 2500 ℃ under high pressure. Therefore, the boron phosphide is added into the aluminum material as a reinforcing phase, so that the strength and the rigidity can be improved, and the high heat conduction and the low thermal expansion performance of the composite material can be ensured. The preparation method greatly reduces the sintering time, and can rapidly sinter to ensure that the sample is densified. The prepared boron phosphide-filled aluminum-based thermal management material can be applied to the fields of heat-conducting substrates, aerospace and the like.

It will be appreciated by those skilled in the art that the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The embodiments disclosed above are therefore to be considered in all respects as illustrative and not restrictive. All changes which come within the scope of or equivalence to the invention are intended to be embraced therein.