Compact and superhard high-entropy boride ceramic as well as preparation method and application thereof

A boride, high-entropy technology, applied in the field of ceramic materials, can solve problems such as high brittleness, and achieve the effect of preventing particle growth, excellent mechanical properties, and reducing particle size

Active Publication Date: 2019-07-12
GUANGDONG UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The high energy ball milling process is used to reduce the particle size. Although a solid solution can be formed, the pollution generated during the high energy milling process cannot be avoided.
At

Method used

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  • Compact and superhard high-entropy boride ceramic as well as preparation method and application thereof
  • Compact and superhard high-entropy boride ceramic as well as preparation method and application thereof
  • Compact and superhard high-entropy boride ceramic as well as preparation method and application thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032] 1. With HfO 2 (powder purity 99.9%, particle size 1μm), ZrO 2 (powder purity 99.9%, particle size 1μm), Nb 2 o 5 (powder purity 99.9%, particle size 2μm), TiO 2 (powder purity 99.9%, particle size 1μm) and Ta 2 o 5 (the purity of the powder is 99.9%, and the particle size is 1 μm). The powder is proportioned in equal atomic proportions, and B 4 C (purity 99.9% of the powder, particle diameter 2 μm) is mixed according to the excess 20wt% of the above-mentioned oxide mixed total amount according to the metering ratio, and the content of graphite powder (purity 99.9%, particle diameter 1 μm) is correspondingly reduced.

[0033] 2. Graphite powder, B 4 C and HfO 2 / ZrO 2 / TiO 2 The molar ratio is 9:6:2, graphite powder, B 4 C and Nb 2 o 5 / Ta 2 o 5 The molar ratio is 14:6:5.

[0034] 3. Put the mixed powder into the graphite crucible, heat up to 900°C at a rate of 10°C / min and keep it for 1 hour, then raise the temperature to 1600°C for 2 hours at a rate of 1...

Embodiment 2

[0039] 1. With HfO 2 (powder purity 99.9%, particle size 1μm), ZrO 2 (powder purity 99.9%, particle size 1μm), Nb 2 o 5 (powder purity 99.9%, particle size 1μm), TiO 2 (powder purity 99.9%, particle size 1μm) and MoO 3 (the purity of the powder is 99.9%, and the particle size is 1 μm). The powder is proportioned in equal atomic proportions, and B 4 C (purity 99.9% of powder, particle size 1 μm) is mixed according to the excess 20wt% of the above-mentioned oxide mixed total amount according to the metering ratio, and the content of graphite powder (purity 99.9%, particle size 1 μm) is correspondingly reduced.

[0040] 2. Graphite powder, B 4 C and HfO 2 / ZrO 2 / TiO 2 The molar ratio of all is 9:6:2, the graphite powder, B 4 C and Nb 2 o 5 The molar ratio is 14:6:5, graphite powder, B 4 C and MoO 3 The molar ratio is 19:6:10.

[0041] 3. Put the final green body after the mixed powder molding into the graphite crucible, raise the temperature to 1000°C at a rate of ...

Embodiment 3

[0046] 1. With HfO 2 (powder purity 99.9%, particle size 2μm), MoO 3 (powder purity 99.9%, particle size 1μm), Nb 2 o 5 (powder purity 99.9%, particle size 2μm), TiO 2 (powder purity 99.9%, particle size 1μm) and Ta 2 o 5 (the purity of the powder is 99.9%, and the particle size is 2 μm) the powder is proportioned in equal atomic proportions, and B 4 C (purity 99.9% of the powder, particle diameter 2 μm) is mixed according to the excess 20wt% of the above-mentioned oxide mixed total amount according to the metering ratio, and the content of graphite powder (purity 99.9%, particle diameter 1 μm) is correspondingly reduced.

[0047] 2. Graphite powder, B 4 C and HfO 2 / TiO 2 The molar ratio of all is 9:6:2, the graphite powder, B 4 C and Nb 2 o 5 / Ta 2 o 5 The molar ratio is 20:6:7, graphite powder, B 4 C and MoO 3 The molar ratio is 19:6:10.

[0048] 3. Put the mixed powder into the graphite crucible, raise the temperature to 1100°C at a rate of 10°C / min and kee...

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Abstract

The invention belongs to the technical field of ceramic materials and discloses novel compact and superhard high-entropy boride ceramic as well as a preparation method and an application thereof. (M1xM2yM3zM4nM5m)B2 ceramic is prepared as follows: metal oxide, B4C and graphite powder are used as raw materials and pressed into a body after ball milling and mixing; high-entropy boride ceramic powderis obtained after thermal treatment; protective atmosphere is charged after the powder is heated to 1,000-1,400 DEG C, then, the powder is heated to 1,800-2,200 DEG C for calcination, and compact andsuperhard (M1xM2yM3zM4nM5m)B2 ceramic is prepared, wherein x is larger than or equal to 0.1 and smaller than or equal to 0.9, y is larger than or equal to 0.1 and smaller than or equal to 0.9, z is larger than or equal to 0.1 and smaller than or equal to 0.9, n is larger than or equal to 0.1 and smaller than or equal to 0.9, m is larger than or equal to 0.1 and smaller than or equal to 0.9, and the sum of x, y, z, n and m is 1. The ceramic material has relative density larger than 98%, hardness of 32-45 GPa, fracture toughness of 3-10 MPa.m<1/2 >and carbon content of 0.1wt%-1wt%.

Description

technical field [0001] The invention belongs to the technical field of ceramic materials, and more specifically relates to a dense superhard high-entropy boride ceramic and its preparation method and application. Background technique [0002] High-entropy ceramics, a new class of crystalline solid-phase solutions containing five or more elements, have attracted much attention due to their unique physical properties and potential applications. So far, much research has focused on high-entropy alloys, which exhibit excellent mechanical, corrosion-resistant, and thermal properties. In contrast to metallic high-entropy alloys, some high-entropy ceramics, especially non-oxide systems, have been discovered. Among them, carbides, borides, and nitrides of transition metals are considered as ultrahigh-temperature ceramics (UHTCs), and the development of high-entropy UHTCs is of great significance for further broadening their applications as structural elements. [0003] Regarding t...

Claims

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Application Information

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IPC IPC(8): C04B35/58C04B35/626C04B35/64
CPCC04B35/58064C04B35/62675C04B35/6268C04B35/64C04B2235/3232C04B2235/3241C04B2235/3244C04B2235/3251C04B2235/3256C04B2235/3821C04B2235/425C04B2235/6562C04B2235/6567C04B2235/666C04B2235/721C04B2235/96
Inventor 郭伟明张岩吴利翔张威林华泰
Owner GUANGDONG UNIV OF TECH
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