WO2014154135A1

WO2014154135A1 - Aluminum oxide dispersion-strengthened titanium aluminum nitride ceramic composite and method for preparing same

Info

Publication number: WO2014154135A1
Application number: PCT/CN2014/074049
Authority: WO
Inventors: 郑卓; 李菊英; 崔玉友; 杨锐
Original assignee: 中国科学院金属研究所
Priority date: 2013-03-26
Filing date: 2014-03-25
Publication date: 2014-10-02
Also published as: CN103183511A; CN103183511B

Abstract

An aluminum oxide (Al₂O₃) dispersion-strengthened titanium aluminum nitride (Ti₄AlN₃) ceramic composite and a method for preparing same. Said composite consists essentially of a Ti₄AlN₃ matrix and an Al₂O₃ strengthening phase, an Al₂O₃ particle dispersion being distributed in the Ti₄AlN₃ matrix, the Al₂O₃ particles being 1-2 microns, and the volume fraction of the Al₂O₃ being 35-45%. The preparation method employs raw powders in the form of in-situ generated of Al₂O₃ particles and in-situ reaction-generated Ti₄AlN₃. The generated Al₂O₃ particles are tiny, constitute a distributed dispersion, and have a volume fraction that can be adjusted to as high as 40%.

Description

Aluminum oxide dispersion-strengthened titanium tetra-aluminum-nitrogen three-ceramic composite material and preparation method thereof

The invention relates to the field of ceramic composite materials, in particular to a titanium tetraaluminum nitride (Ti ₄ AlN ₃ ) ceramic composite material dispersed by using aluminum oxide (Al _{2 2} _{3 3} ) and a preparation method thereof.

Background technique

The crystal structure of Ti ₄ AlN ₃ was discovered by JCSchuster et al. in 1984 and was initially considered to be Ti ₃ Al ₂ N ₂ . After that, many scholars have conducted detailed research on Ti ₃ Al ₂ N ₂ materials. In 1997, HeeDong Lee and William TPetuskey found that Ti ₃ Al ₂ N ₂ did not fully meet the stoichiometric ratio, and proposed a more accurate measurement ratio of 3⁄4^.^ ₂ . On this basis, WMBousum et al. changed the chemical formula to Ti ₄ AlN ₃ and studied it into one of M _n+1 AX _n ternary ceramic materials. M in the M _n+1 AX _n material is a transition element, A is a main group element, X is C or N, where n is 1, 2 or 3, such as Ti ₃ SiC ₂ , Ti ₄ SiC ₃ , Ti ₂ AlN, Cr ₂ GaC and the like. These ternary ceramics have many things in common, such as softer than ordinary ceramics (3~6GPa), and are easy to process. They are different from traditional binary nitrides and carbide ceramics, and are difficult to process.

Ti ₄ AlN ₃ is a ternary nitride ceramic belonging to a close-packed hexagonal structure, and the space group is P63/mmc. The Ti ₆ N octahedron and the A1 atomic layer are periodically stacked along the c-axis direction. Since the intracellular metal bond, the covalent bond, and the ionic bond coexist, Ti ₄ AlN ₃ has the advantages of electrical conductivity and thermal conductivity of the metal, workability, high strength of the ceramic, and high modulus. Ti ₄ AlN _{3 is} generally made of TiH ₂ , A1N and TiN powders, and is isothermally pressed at 1275 ° C / 24 h / 70 MPa. A1 ₂ 0 ₃ is an ionic oxide with a slightly distorted close-packed hexagonal structure, 0 ² · is located at the hexagonal lattice point of the close-packed, and the Al ³⁺ interstitial is at the octahedral gap position of 0 ² ·. This structure also has good stability near the melting point. Due to the density of A1 ₂ 0 ₃ and Ti ₄ AlN ₃ , the thermal expansion coefficient is very close, and the hardness and compressive strength complement each other. It is selected in A1 ₂ 0 ₃ dispersion strengthened Ti ₄ AlN. ₃ matrix, can improve its high temperature strength and oxidation resistance. The main properties of A1 ₂ 0 ₃ and Ti ₄ AlN ₃ are shown in Table 1.

Table 1 Physical and mechanical properties of Ti ₄ AlN ₃ and A1 ₂ 0 ₃

Performance Ti ₄ AlN ₃ Α1 ₂ 0 ₃

Density (g/cm ³ ) 4.61 3.9 Vickers hardness (GPa) 2.5 18 Compressive strength (MPa) 480 2600 Resistivity (μΩ·ιη) 2.64, 2.0 >1018

Thermal expansion coefficient (Κ ⁴ ) 9.7χ 10" ⁶ 8.3χ 10" ⁶ Young's Modulus (GPa) 310

386

Shear modulus (GPa) 127 175

Melting point 2054

Generally, the A1 ₂ 0 ₃ dispersion-strengthened Ti ₄ AlN ₃ composite material obtained by powder hot pressing or hot pressing is formed by the following methods:

(1) A1 ₂ 0 ₃ powder and Ti ₄ AlN ₃ powder are used, which are not in situ reaction type;

(2) A1 ₂ 0 ₃ powder and raw powder generated Ti ₄ AlN _3, belonging to the in situ reaction of Ti ₄ AlN ₃ type; the presence of a first and a second method is that uneven distribution of A1 ₂ 0 _3, Easy to agglomerate, the particle length is obvious, and this phenomenon becomes more obvious as the volume fraction of A1 ₂ 0 ₃ increases.

Summary of the invention

The object of the present invention is to provide a titanium tetra-aluminum-nitrogen three-ceramic composite material and a preparation method thereof by using aluminum oxide dispersion, the ceramic composite material has high hardness, high strength and good oxidation resistance, and has electrical conductivity and processing. Sex.

The technical solution of the present invention is:

A two-aluminum oxide dispersion-strengthened titanium tetra-aluminum-nitrogen three-ceramic composite material, which is mainly composed of a Ti ₄ AlN ₃ matrix and an A1 ₂ 0 ₃ strengthening phase, and the A1 ₂ 0 ₃ particles are dispersed in Ti ₄ AlN ₃ In the matrix, the A1 ₂ 0 ₃ particles are 1 to 2 μm, the volume fraction of A1 ₂ 0 ₃ is 35-45%, and the volume fraction of Ti ₄ AlN ₃ is 50 to 60%.

The aluminum oxide dispersion-strengthened titanium tetra-aluminum-nitrogen three-ceramic composite material preferably has a volume fraction of A1 ₂ 0 ₃ of 40%. The aluminum oxide dispersion-strengthened titanium tetra-aluminum-nitrogen three-ceramic composite material, the volume fraction of Ti ₄ AlN ₃ is preferably 50~

55%.

The aluminum oxide dispersion-strengthened titanium tetra-aluminum-nitrogen three-ceramic composite material preferably has an A1 ₂ 0 ₃ particle of 1.5 to 2 μm. The Al2O3 dispersion-strengthened titanium tetra-aluminum-nitrogen three-ceramic composite material, and the rest is a small amount of reaction phases Al ₃ Ti and A1N; wherein, the volume fraction of Al ₃ Ti is 0 to 7.5%, and the volume fraction of A1N is 0. ~7.5%.

The preparation method of the aluminum oxide dispersion-strengthened titanium tetra-aluminum-nitrogen three-ceramic composite material comprises the following steps: First, in a mixed atmosphere of N ₂ , H ₂ and Ar of 0.7 to 1.2 atmospheres, wherein N ₂ accounts for total 4 to 15% by volume, and the volume ratio of H ₂ to Ar is 1:0.8 to 1.2, and Ti _{3 ()} A is continuously supplied! Synthesis of composite nano-powder by hydrogen plasma metal reaction under the condition of ~ Ti ₆₍₎ Al master alloy rod;

Then, the nano-powder is densified by hot isostatic pressing method, the process parameters are: temperature is 1200 ° C ~ 1400 ° C, pressure is 100~160 MPa, time is l~2h, vacuum degree is 2xlO ^-2 ~ 5xl (r ³ Pa. The preparation method of the aluminum oxide dispersion-strengthened titanium tetra-aluminum-nitrogen three-ceramic composite material has an average particle diameter of 100 to 150 nm in the process of synthesizing the nano-powder of the composite material by the hydrogen plasma metal reaction method.

The preparation method of the aluminum oxide dispersion-strengthened titanium tetra-aluminum-nitrogen three-ceramic composite material, in the process of synthesizing the nano-powder of the composite material by the hydrogen plasma metal reaction method, N ₂ preferably accounts for 6 to 12% of the total volume content.

The preparation method of the aluminum oxide dispersion-strengthened titanium tetra-aluminum-nitrogen three-ceramic composite material preferably has a temperature of 1250 ° C to 1350 ° C during densification of the nano powder by a hot isostatic pressing method.

The A1 ₂ 0 ₃ dispersion-strengthened Ti ₄ AlN ₃ ceramic composite material provided by the invention and the preparation method thereof have the advantages of:

1. The invention directly uses the raw material powder to generate A1 ₂ 0 ₃ particles in situ and in situ to form Ti ₄ AlN ₃ type, and the in situ generated A1 ₂ 0 ₃ particles are fine and dispersed, and the volume fraction can be adjusted up to 40%.

2. The Ti ₄ AlN ₃ matrix and the A1 ₂ _{3 3} strengthening phase in the composite material of the invention are both formed in situ, and the A1 ₂ 0 ₃ particles are 1~

2 microns, dispersed in the Ti ₄ AlN ₃ matrix.

3. The microhardness of the ceramic composite prepared by the invention is 2.6 times that of Ti ₄ AlN ₃ , and the strengthening effect is remarkable.

4. The invention adopts the nano powder synthesis block to react quickly and has a short time, which can save a lot of energy.

5. The composite material of the invention has good comprehensive properties, the density is 4.2~4.4 g/cm ³ , the Vickers hardness is 6.5~7.5 GPa, the compressive strength is 1750~1850 MPa, and the resistivity is 0.6~0.8 μΩ·ιη.

DRAWINGS

Figure 1 shows the morphology of an alloy nanopowder prepared by a hydrogen plasma metal reaction method, which is a spherical powder (inside is a TV diffraction spectrum). Figure 2 shows the morphology of the alloy nanopowder prepared by the hydrogen plasma metal reaction method, which is a cubic powder (the inside is an electron diffraction spectrum).

Fig. 3 is a particle size distribution diagram of the total nanopowder prepared by the hydrogen plasma metal reaction method.

Figure 4 is an external view of the prepared ceramic composite.

Figure 5 is a metallographic photograph of the prepared ceramic composite.

Figure 6 is an X-ray diffraction pattern of the prepared ceramic composite.

Figure 7 is a graph showing the relationship between the microhardness and the load of the prepared ceramic composite.

detailed description

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

The aluminum oxide dispersion-enhanced titanium tetra-aluminum-nitrogen three-ceramic composite material is mainly composed of a Ti ₄ AlN ₃ matrix and a Α1 ₂ 0 ₃ strengthening phase, and the Α1 ₂ 0 ₃ particles are dispersed and distributed in the Ti ₄ AlN ₃ matrix, A1 ₂ 0 ₃ particles are 1~2 microns, A1 ₂ 0 ₃ volume fraction is 35~45% (preferably 40%), Ti ₄ AlN ₃ volume fraction is 50~60%, and the rest is a small amount of reaction phase Al ₃ Ti And ΑΙΝο The preparation method of the aluminum oxide dispersion-strengthened titanium tetra-aluminum-nitrogen three-ceramic composite material comprises the following steps: First, in a mixed atmosphere of N ₂ , H ₂ and Ar of 0.7 to 1.2 atmospheres, wherein N ₂ accounts for the total volume The content of 4 to 15%, the ratio of 3⁄4 to Ar is 1:0.8 to 1.2, and the Ti ₃₀ A is continuously supplied! ~ Ti ₆₀ Al (Ti atomic percentage is 30~ ₆₀ %) Under the condition of master alloy rod, the nano-powder of composite material is synthesized by hydrogen plasma metal reaction method; the projection electron microscope morphology of nano-powder is shown in Figure 1, Figure 2, There are two typical morphologies: one is spherical or nearly spherical particles (Figure 1), and the other is square particles (Figure 2). Electron diffraction analysis shows that the square particles are TiN; Hydrogen plasma metal reaction preparation The particle size distribution of the nanopowder is shown in Fig. 3, and the macroscopic photograph of the ceramic composite is shown in Fig. 4. It can be seen that the average particle size of the nanopowder is 120 nm.

Among them, the hydrogen plasma metal reaction method uses conventional techniques, which can be found in the literature: [1] Sun Weimin, Jin Shouri. Preparation of M-TiN composite ultrafine particles by reactive plasma-metal reaction method. Materials Science and Technology. 1997, 5 (4): P26-29; [2] Li Xingguo, Liao Fuhui. Synthesis of metal and ceramic nanoparticles by DC arc plasma method. Chinese Journal of Process Engineering, 2002, 2(4): P295-300; [3] Lin Feng, Jiang Yanlin, Wen Yong Peng, Zhang Jianwei. Preparation of nano-powder technology by DC arc plasma and its application. Volkswagen Technology. 2012, 01: P99-103.

Then, the nanopowder is densified by a hot isostatic pressing method, and the process parameters are as follows: temperature is 1200 ° C to 1400 ° C, pressure is 100 to 160 MPa, time is 1 to 2 h, and vacuum degree is 2 χ 10 · ² 〜 5 χ 10· ³ Ρ. The prepared composites were subjected to metallographic observation, X-ray phase analysis, resistivity and hardness test. The metallographic morphology of the composites prepared is shown in Fig. 5. The black particles in the figure are Α1 ₂ 0 ₃ and the size is about 1.5 μm. , dispersed in the Ti ₄ AlN ₃ matrix. The X-ray diffraction pattern of the prepared composite is shown in Fig. 6. The results show that the composite mainly forms phases: A1 ₂ 0 ₃ and Ti ₄ AlN ₃ , and additionally contains a small amount of reaction phases Al ₃ Ti and A1N. See curve between the load microhardness composite material prepared 7, can be seen from this figure, the hardness of the composite is 2.6 Ti ₄ AlN ₃ times the hardness significantly strengthened Ti ₄ AlN _3-phase , and the hardness does not change significantly with the load.

Example 1

First, in a mixed atmosphere of 0.77 atmospheres of N ₂ , 3⁄4 and Ar, wherein N ₂ accounts for 9% of the total volume, and the volume ratio of 3⁄4 to Ar gas is 1:1, and the Ti ₄₈ Al (atomic percentage) is continuously supplied. Under the condition of the alloy bar, the nano-powder used for preparing the composite material was synthesized by a hydrogen plasma metal reaction method, and the average particle diameter of the nano-powder was 120 nm.

Then, nano powder was weighed 25g and placed in (p38mmx l5mm of titanium within the envelope, placed in a hot isostatic press, evacuated to a vacuum degree of 3x l0- ³ Pa, kept at 1280 ° C / 150MPa conditions 1 hour. In the obtained composite, the A1 ₂ 0 ₃ particles are 1 to 2 μm, the volume fraction of A1 ₂ 0 ₃ is 40%, the volume fraction of Ti ₄ AlN ₃ is 54%, and the rest is a small amount of reaction phase Al ₃ The volume fraction of Ti and A1N was 6%. In this example, the composite had a density of 4.3 g/cm ³ , a Vickers hardness of 6.86 GPa, a compressive strength of 1798 MPa, and a resistivity of 0.716 μΩ·ιη.

Example 2 First, in a mixed atmosphere of N ₂ , 3⁄4 and Ar at 1.0 atmosphere, wherein N ₂ accounts for 6% of the total volume, and the volume ratio of 3⁄4 to Ar gas is 1:1, and the Ti ₄₈ Al (atomic percentage) is continuously supplied. Under the condition of the alloy bar, the nanometer powder used for preparing the composite material is synthesized by a hydrogen plasma metal reaction method, and the average particle diameter of the nano powder is 110 nm.

Then, weigh 25g of nano-powder, placed in a p38mmxl5mm pure titanium sheath, placed in a hot isostatic press, vacuumed, vacuum 3xlO- ³ Pa, and kept at 1250 °C / 145MPa for 1.5 hours In the obtained composite, the A1 ₂ 0 ₃ particles are 1 to 2 μm, the volume fraction of A1 ₂ 0 ₃ is 35%, the volume fraction of Ti ₄ AlN ₃ is 60%, and the rest is a small amount of reaction phase Al ₃ Ti and The volume fraction of A1N is 5%. In this embodiment, the composite has a density of 4.24 g/cm ³ , a Vickers hardness of 6.80 GPa, a compressive strength of 1789 MPa, and a resistivity of 0.788 μΩ·ιη.

Example 3

First, in a mixed atmosphere of Ν ₂ , Η ₂ and Ar at 0.9 atmospheres, wherein N ₂ accounts for 12% of the total volume, and the volume ratio of 3⁄4 to Ar gas is 1:1, and Ti ₄₈ Al (atomic percentage) is continuously supplied. Under the condition of the master alloy bar, the nanopowder used for preparing the composite material was synthesized by a hydrogen plasma metal reaction method, and the average particle diameter of the nanopowder was 130 nm.

Then, weigh 25g of nano-powder, placed in a p38mmxl5mm pure titanium sheath, placed in a hot isostatic press, vacuumed, vacuum 3xlO- ³ Pa, and kept at 1350 °C / 155MPa for 2 hours In the obtained composite, the A1 ₂ 0 ₃ particles are 1 to 2 μm, the volume fraction of A1 ₂ 0 ₃ is 45%, the volume fraction of Ti ₄ AlN ₃ is 50%, and the rest is a small amount of reaction phase Al ₃ Ti and The volume fraction of A1N is 5%. In this embodiment, the density of the composite material is 4.32 g/cm ³ , the Vickers hardness is 7.02 GPa, the compressive strength is 1804 MPa, and the electrical resistivity is 0.661 μΩ·ιη.

Example 4

First, in a mixed atmosphere of Ν ₂ , 3⁄4 and Ar at 0.8 atmospheres, wherein N ₂ accounts for 5% of the total volume, and the volume ratio of 3⁄4 to Ar gas is 1:1, and the Ti ₃₄ Al (atomic percentage) is continuously supplied. Under the condition of the alloy bar, the nanometer powder used for preparing the composite material is synthesized by a hydrogen plasma metal reaction method, and the average particle diameter of the nano powder is 100 nm.

Then, weigh 25g of nano-powder, placed in a p38mmxl5mm pure titanium sheath, placed in a hot isostatic press, vacuumed, vacuum 2xlO- ³ Pa, and incubated at 1400 °C / 120MPa for 1 hour In the obtained composite, the average particle size of A1 ₂ 0 ₃ is 1.5 μm, the volume fraction of A1 ₂ 0 ₃ is 36%, the volume fraction of Ti ₄ AlN ₃ is 52%, and the rest is a small amount of reaction phases Al ₃ Ti and A1N. The volume fraction is 12%. In this embodiment, the composite has a density of 4.23 g/cm ³ , a Vickers hardness of 6.95 GPa, a compressive strength of 1778 MPa, and a resistivity of 0.753 μΩ·ιη.

Example 5

First, in a mixed atmosphere of Ν ₂ , 3⁄4 and Ar at 1.2 atmospheres, where N ₂ is 10% of the total volume, and the volume ratio of 3⁄4 to Ar is 1:1, and the Ti _6Q Al (atomic percentage) is continuously supplied. Under the condition of the alloy bar, the nano powder used for preparing the composite material is synthesized by a hydrogen plasma metal reaction method, and the average particle diameter of the nano powder is 150 nm. Then, weigh 25g of nano-powder, placed in a p38mmx l5mm pure titanium sheath, placed in a hot isostatic press, vacuumed, vacuum 4x lO- ³ Pa, 1300 ° C / 130MPa conditions for 2 hours. composite material obtained in A1 ₂ 0 ₃ having an average particle of 1.2 micron, the volume fraction of A1 ₂ 0 ₃ is 42%, Ti volume fraction ₄ AlN ₃ is 54%, the rest phase Al ₃ Ti is a small amount of reaction The volume fraction of A1N is 4%. In this embodiment, the density of the composite material is 4.31 g/cm ³ , the Vickers hardness is 7.12 GPa, the compressive strength is 1816 MPa, and the electrical resistivity is 0.687 μΩ·ιη ₀

The results of the examples show that the ceramic composite of the present invention mainly consists of a Ti ₄ AlN ₃ matrix and a Α1 ₂ 0 ₃ strengthening phase, and the Α1 ₂ 0 ₃ particles are dispersed in the Ti ₄ AlN ₃ matrix. The invention directly uses the raw material powder to generate A1 ₂ 0 ₃ particles in situ and in situ to form Ti ₄ AlN ₃ type, and the in situ generated A1 ₂ 0 ₃ particles are fine and dispersed, and the volume fraction can be adjusted up to 40%. about. The ceramic composite material of the invention has high hardness, high strength and good oxidation resistance, and has electrical conductivity and workability.

Claims

Rights request

1. An aluminum oxide dispersion strengthened titanium tetraaluminum nitrogen three ceramic composite material, characterized in that the ceramic composite material is mainly composed of a Ti ₄ AlN ₃ matrix and an A1 ₂ 0 ₃ strengthening phase, and the A1 ₂ 0 ₃ particles are dispersed Distributed in the Ti ₄ AlN ₃ matrix, the A1 ₂ 0 ₃ particles are 1 to 2 microns, the volume fraction of A1 ₂ 0 ₃ is 35 to 45%, and the volume fraction of Ti ₄ AlN ₃ is 50 to 60%.

2. The aluminum oxide dispersion-strengthened titanium tetraaluminum nitrogen three ceramic composite material according to claim 1, characterized in that,

The volume fraction of A1 ₂ 0 ₃ is preferably 40%.

3. The aluminum oxide dispersion-strengthened titanium tetraaluminum nitride ceramic composite material according to claim 1, characterized in that the volume fraction of Ti ₄ AlN ₃ is preferably 50 to 55%.

4. The aluminum oxide dispersion-strengthened titanium tetraaluminum nitride ceramic composite material according to claim 1, characterized in that the A1 ₂ 0 ₃ particles are preferably 1.5 to 2 microns.

5. The aluminum oxide dispersion-strengthened titanium tetraaluminum nitrogen three ceramic composite material according to claim 1, characterized in that the remainder is a small amount of reaction phases Al ₃ Ti and A1N; wherein the volume fraction of Al ₃ Ti is 0 ~7.5%, the volume fraction of A1N is 0~7.5%.

6. A method for preparing the aluminum oxide dispersion-strengthened titanium tetraaluminum nitride ceramic composite material according to claim 1, characterized in that it includes the following steps:

First, in a mixed atmosphere of N ₂ , H ₂ and Ar at 0.7 to 1.2 atmospheric pressure, in which N ₂ accounts for 4 to 15% of the total volume content, the volume ratio of H ₂ to Ar is 1:0.8 to 1.2, in a continuous supply Ti ₃₍₎ A! ~ Under the conditions of Ti ₆₍₎ Al master alloy rod, the nanopowder of the composite material is synthesized using the hydrogen plasma metal reaction method;

Then, the hot isostatic pressing method is used to densify the nanopowder. Process parameters: temperature is 1200°C~1400°C, pressure is 100~160MPa, time is 1~2h, vacuum degree is 2xlO ^-2 ~5xl(r ³ Pa.

7. The preparation method of aluminum oxide dispersion-strengthened titanium tetraaluminum nitride ceramic composite material according to claim 6, characterized in that, in the process of synthesizing the nanopowder of the composite material using the hydrogen plasma metal reaction method, the nanopowder The average particle size is 100~150 nanometers.

8. The method for preparing the aluminum oxide dispersion-strengthened titanium tetraaluminum nitrogen three ceramic composite material according to claim 6, characterized in that, in the process of synthesizing the nanopowder of the composite material using the hydrogen plasma metal reaction method, N ₂ is preferably Accounting for 6~12% of the total volume content.

9. The preparation method of aluminum oxide dispersion-strengthened titanium tetraaluminum nitride ceramic composite material according to claim 6, characterized in that, during the densification process of nanopowder using hot isostatic pressing method, the temperature is preferably 1250°C °C~1350°C _o