Method for synthesizing Nb/Nb5Si3 composite materials at high temperature through microwave induced self propagating

A self-propagating high-temperature, composite material technology, applied in the field of microwave-induced self-propagating high-temperature synthesis of Nb/Nb5Si3 composite materials, can solve the problem of no Nb5Si3 formation, and achieve the effect of avoiding oxidation reactions

Inactive Publication Date: 2010-07-28
HUAZHONG UNIV OF SCI & TECH
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

And the patent "A Iridium Niobium Silicon Superalloy Material and Its Preparation Method" (Patent Publication No. 1786236) and the patent "Chromium Modified Silicide Coating Resistant to High Temperature Oxidation and its Preparation Method" (Patent Publication No. 1818124) It also only involves the formation of niobium silicon and other elements together to form high-temperature materials, and there is no formation of Nb5Si3

Method used

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  • Method for synthesizing Nb/Nb5Si3 composite materials at high temperature through microwave induced self propagating
  • Method for synthesizing Nb/Nb5Si3 composite materials at high temperature through microwave induced self propagating
  • Method for synthesizing Nb/Nb5Si3 composite materials at high temperature through microwave induced self propagating

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Embodiment 1

[0033] Nb-37.5at% Si sample has been self-propagating sintering under the protection of argon after evacuation, and Nb and Si powder are pressed by Nb 5 Si 3 The chemical formula of the preparation Nb:Si atomic ratio is the composite powder of 62.5:37.5, ball milled in the planetary ball mill for 10h, the ball milling medium is alcohol, the ball-to-material ratio is 3:1, and 2wt% stearic acid is added as a process control agent. The samples after ball milling were dried and molded under a pressure of 300MPa. The molded sample is placed in a microwave cavity, vacuumed to 2Pa, then filled with fluid argon, and self-propagating sintering is carried out under the protection of argon. Start the microwave source, the heating rate is 10-40°C / min, the sintering temperature is 1200°C, and the holding time is 15min. After the furnace cools down, take out the sample. The fired sample is mainly composed of niobium oxide, SiO 2 and a small amount of Nb 3 Si and Nb 5 Si 3 composition...

Embodiment 2

[0035] Nb-18.7at% Si samples embedded in Al 2 o 3 Self-propagating sintering in +SiC+C powder

[0036] Prepare Nb and Si powders according to the eutectic composition into composite powders with an atomic ratio of Nb:Si of 81.3:18.7, and mill them in a planetary ball mill for 10 hours. Fatty acid as a process control agent. The samples after ball milling were dried and molded under a pressure of 100 MPa. The molded sample was embedded in Al 2 o 3 +SiC+C powder and then put it into the microwave cavity, vacuumize to 2Pa, fill it with fluid argon, and carry out self-propagating sintering under the protection of argon. The ratio of the above-mentioned protective powder is Al 2 o 3 : 20wt%, SiC: 78wt%, C: 2wt%. Start the microwave source, the heating rate is 10-40°C / min, the sintering temperature is 1300°C, and the holding time is 30min. After the furnace cools down, take out the sample. The fired sample is mainly composed of Nb, Nb 5 Si 3 and a small amount of Nb 3 Si...

Embodiment 3

[0038] Nb-18.7at% Si samples embedded in Al 2 o 3 Self-propagating sintering in +SiC+Al powder

[0039] Prepare Nb and Si powders according to the eutectic composition into composite powders with an atomic ratio of Nb:Si of 81.3:18.7, and mill them in a planetary ball mill for 10 hours. Fatty acid as a process control agent. The samples after ball milling were dried and molded under a pressure of 300MPa. The molded sample was embedded in Al 2 o 3 +SiC+Al powder and then put it into the microwave cavity, vacuumize to 2Pa, fill it with fluid argon, and carry out self-propagating sintering under the protection of argon. The ratio of the above-mentioned protective powder is Al 2 o 3 : 18wt%, SiC: 80wt%, Al: 2wt%. Start the microwave source, the heating rate is 10-40°C / min, the sintering temperature is 1300°C, and the holding time is 30min. After the furnace cools down, take out the sample. The fired sample is mainly composed of Nb, Nb 5 Si 3 and a small amount of Nb 3 ...

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Abstract

The invention provides a method for synthesizing Nb/Nb5Si3 composite materials at a high temperature through microwave induced self propagating, which consists of an ingredient recipe and a synthesis technology, wherein the ingredient recipe comprises pure niobium powder and pure silicon powder according to a mixing ratio of Nb-(5-37.5 at.%)Si, and the synthesis technology comprises the following steps: (1), firstly, proportionally and uniformly mixing all ingredient powder in the ingredient recipe to obtain composite powder; (2) grinding the composite powder into fine powder with the granularity of 800 meshes; (3) forming the ground composite powder at the pressure between 100 and 300 MPa; and (4) placing the formed materials into a microwave cavity for self propagating sintering by the microwaves under the protection of argon gas, and flowing argon gas is inflated into the microwave cavity during the self propagating sintering after vacuum pumping. The invention fully utilizes the advantages of the microwave sintering technology and the self propagating high-temperature synthesis, synthesized test samples do not contain oxide, the preparation time is short, and the reaction is complete.

Description

technical field [0001] The invention relates to microwave technology and high-temperature structural material technology, specifically a microwave-induced self-propagating high-temperature synthesis of Nb / Nb 5 Si 3 Composite methods. A kind of in situ synthesis of Nb / Nb 5 Si 3 A new approach to high-temperature structural composites. Background technique [0002] Due to their high melting point, low density and thermal conductivity, especially their excellent high-temperature performance at high temperature, transition metal silicides have attracted widespread attention at home and abroad. Silicides used as structures are mainly produced in Mo-Si, Nb-Si and Ti-Si systems. Nb 5 Si 3 (2480°C) has a higher melting point and a lower density (7.16g / cm 3 ). Moreover, the compound also has good oxidation resistance and electrical conductivity. Therefore, it has potential application prospects in high-temperature structural materials. Although Nb 5 Si 3 It has potential...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B22F3/23
Inventor 王爱华杨妮闫华宋武林董选普李建军
Owner HUAZHONG UNIV OF SCI & TECH
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