A kind of dense niobium aluminum silicon carbon solid solution material and preparation method thereof

An aluminum-silicon-carbon, solid solution technology, applied in the field of ceramic materials, can solve problems such as no reports, and achieve the effects of simple process, improved toughness and hardness, and dense structure

Active Publication Date: 2016-08-31
NANJING TECH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Currently, with respect to Nb 4 AlC 3 There is no report on the solid solution modification research at home and abroad

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] The raw material powder is weighed according to the molar ratio n(Nb):n(Al):n(Si):n(C)=4:1.02:0.08:2.7, then dry-mixed in a polyethylene tank for 24 hours, and then placed on the surface coated with BN is cold-pressed in a graphite mold and hot-pressed and sintered in an argon atmosphere. Raise the temperature to 1700°C at a rate of 25°C / min, pressurize to a pressure of 30MPa after reaching the sintering temperature, and sinter in-situ reaction hot pressing for 1h. The obtained bulk material is Nb 4 Al 0.92 Si 0.08 C 3 , the apparent porosity measured by the Archimedes method is 0.41%, the three-point bending strength of the material tested on the universal testing machine reaches 528MPa, and the fracture toughness of the material measured by the unilateral notched beam method reaches 7.9MPa m 1 / 2 , the Vickers hardness of the material measured by the indentation method reached 3.5GPa, and the electrical conductivity of the material measured by the four-probe method...

Embodiment 2

[0019] The raw material powder is weighed according to the molar ratio n(Nb):n(Al):n(Si):n(C)=4:1.05:0.05:2.7, then dry-mixed in a polyethylene tank for 24 hours, and then placed on the surface to be coated with BN is cold-pressed in a graphite mold and hot-pressed and sintered in an argon atmosphere. Raise the temperature to 1680°C at a rate of 15°C / min, and pressurize to a pressure of 30MPa after reaching the sintering temperature for in-situ reaction hot-pressing sintering for 2h. The obtained bulk material is Nb 4 Al 0.95 Si 0.05 C 3 , the apparent porosity measured by the Archimedes method is 0.37%, the three-point bending strength of the material tested on the universal testing machine reaches 518MPa, and the fracture toughness of the material measured by the unilateral notched beam method reaches 7.7MPa m 1 / 2 , the Vickers hardness of the material measured by the indentation method reached 3.3GPa, and the electrical conductivity of the material measured by the four-...

Embodiment 3

[0021] The raw material powder is weighed according to the molar ratio n(Nb):n(Al):n(Si):n(C)=4:1.07:0.03:2.7, then dry-mixed in a polyethylene tank for 24 hours, and then placed on the surface coated with BN is cold-pressed in a graphite mold and hot-pressed and sintered in an argon atmosphere. Raise the temperature to 1720°C at a rate of 20°C / min, and pressurize to a pressure of 25MPa after reaching the sintering temperature for in-situ reaction hot-pressing sintering for 1h. The obtained bulk material is Nb 4 Al 0.97 Si 0.03 C 3 Solid solution, the apparent porosity measured by Archimedes method is 0.31%, the three-point bending strength of the material tested on the universal testing machine reaches 462MPa, and the fracture toughness of the material measured by the unilateral notched beam method reaches 7.3MPa m 1 / 2 , the Vickers hardness of the material measured by the indentation method reached 2.8GPa, and the electrical conductivity of the material measured by the f...

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Abstract

The invention relates to a dense niobium-aluminum-silicon-carbon solid solution material and a preparation method thereof; the chemical structural formula of the niobium-aluminum-silicon-carbon solid solution material is Nb 4 al 1‑x Si x C 3 , where the value range of x is 0.03≤x≤0.08. Synthesis by in-situ hot pressing process: the molar ratio of raw materials niobium powder, aluminum powder, silicon powder and graphite powder is: n(Nb):n(Al):n(Si):n(C)=4: (1.02 ~ 1.07): (0.03 ~ 0.08): 2.7 After mixing evenly by physical and mechanical methods, put it into a graphite mold coated with a BN protective coating on the surface for cold pressing, and then place it in a vacuum hot pressing furnace with a protective atmosphere Hot pressing and sintering. The invention has simple process and excellent material performance.

Description

Technical field: [0001] The invention relates to the field of ceramic materials, in particular to a dense niobium-aluminum-silicon-carbon solid solution material and a preparation method thereof. Background technique: [0002] Niobium aluminum carbon (Nb 4 AlC 3 ) is a new type of ternary layered ceramic material, which combines many advantages of metal and ceramics, has high electrical conductivity and thermal conductivity, excellent damage tolerance, ductility and high temperature plasticity, and can be machined. At the same time, it has low density, high melting point and elastic modulus, low friction coefficient and good self-lubricating properties. More importantly, Nb 4 AlC 3 It has very excellent high-temperature mechanical properties and has broad application prospects in high-temperature structural materials and electrode or brush materials. But Nb 4 AlC 3 The strength and hardness at room temperature are not ideal, and the oxidation resistance is poor, which...

Claims

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Application Information

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Patent Type & AuthorityPatents(China)
IPC IPC(8): C04B35/52C04B35/622
Inventor杨建张波潘丽梅丘泰
OwnerNANJING TECH UNIV