CN1611623A - Nickel-silicon base intermetallic compound composite material and its preparing method - Google Patents

Abstract

The invention discloses a nickel-silicon-based intermetallic compound composite material and a preparation method thereof. The raw material of the material is composed of 23.5-75.6 nickel, 3.7-12.1 silicon, 1.9-11.3 chromium trioxide, 6.3-37.3 chromium trioxide, 4.1-24.2 aluminum, and 0-1.2 (mass percentage) of activated carbon. The preparation method of the composite material adopts a combustion synthesis melting method, and utilizes the heat released by the chemical reaction itself to synthesize a high-purity dense Ni ₃ Si-based intermetallic compound composite material. Compared with the smelting method or the hot pressing sintering method, the method has simple process and required equipment, and the cost is obviously reduced, and the prepared material has good microstructure and performance.

Description

Nickel-silicon-based intermetallic compound composite material and preparation method thereof

technical field

The invention describes a nickel-silicon-based intermetallic compound composite material and a preparation method thereof.

Background technique

Ni ₃ Si-based intermetallic compounds and their composite materials have high strength, high hardness and excellent acid resistance and high temperature performance, and are high-temperature structural materials with important application prospects.

The traditional smelting or powder metallurgy method to prepare Ni ₃ Si-based intermetallic compounds and their composite materials requires a high temperature above 1200°C, and the powder metallurgy method also requires a pressure of 100 MPa. These methods require complex equipment, high energy consumption, long production cycle and high cost.

Contents of the invention

The object of the present invention is to overcome the deficiencies in the prior art and provide a nickel-silicon-based intermetallic compound composite material and a preparation method thereof.

A nickel-silicon-based intermetallic compound composite material, characterized in that the raw materials of the material are nickel 23.5-75.6, silicon 3.7-12.1, dichromium trioxide 1.9-11.3, chromium trioxide 6.3-37.3, aluminum 4.1-24.2, activated carbon 0 ~1.2 (mass percent) composition.

The preparation method of the composite material adopts a combustion synthesis melting method, and utilizes the heat released by the chemical reaction itself to synthesize a high-purity dense Ni ₃ Si-based intermetallic compound composite material. Due to the short-term melting process of the reaction products and the density difference and mutual melting characteristics between the reaction products, the reinforcement phase can be mixed spontaneously with the matrix and separated from impurities quickly, and composite materials with different self-generated phase reinforcements can be obtained conveniently. Pressurization with inert gas increases the density of the material and improves the microstructure of the material.

The preparation method of the _Ni3Si -based intermetallic compound composite material of the present invention is characterized in that the method comprises: nickel 23.5-75.6, silicon 3.7-12.1, dichromium trioxide 1.9-11.3, chromium trioxide 6.3-37.3 , aluminum 4.1-24.2, activated carbon 0-1.2 Weigh the powdered reaction materials and mix them evenly, place them in a graphite mold and press them into a reaction embryo with a pressure of 10-30MPa; place the graphite mold with the reaction embryo in the reaction vessel In the process, the reaction vessel is purged with an inert gas to remove the air therein; the billet is heated to 150°C-200°C, and kept at this temperature for 1-2 hours; then the gas desorbed from the surface of the reaction material is removed from the vessel, Pass in an inert gas of 3-10MPa; continue heating to about 250-300°C, and initiate the reaction through an igniter. The igniter is a mixture composed of permanganate, magnesium powder, and sulfide. Each component of permanganate : magnesium powder: the mass ratio of sulfide is (1.0-2.0): (1.5-2.5): (1-2.0), and the percentage by weight of igniter mixture accounts for 2～10% of total reaction mass; The material cooled to room temperature with the reaction vessel.

The Ni ₃ Si-based intermetallic compound material with high purity, compact microstructure and excellent performance was obtained by using the above process. Compared with traditional smelting and hot pressing sintering methods, the combustion synthesis and melting method for preparing Ni ₃ Si-based intermetallic compound materials adopted in the present invention requires a large reduction in the required external temperature, simple preparation process and required equipment, and significantly reduced preparation costs . The material prepared by the method has the advantages of high purity and compact structure, and the obtained material has high strength, high hardness and good wear resistance. The performance of the material prepared by the invention has good reproducibility, and the dispersion degree of the measured performance data is not more than 10%.

The invention adopts the combustion synthesis melting method to prepare the _Ni3Si -based intermetallic compound composite material, avoids the deficiency of the prior art, has simple equipment, simple process, short production cycle and low cost.

The hardness measurement conditions are as follows: a load of 500 g and a loading duration of 5 s. The flexural strength of the material was measured by a three-point bending test. The sample size was 30×3×3mm, the span was 25mm, and the downward movement speed of the indenter was 0.1mm/min. The wear test is carried out on a ball-disc type SRV fretting friction and wear testing machine. The disc is the material of the present invention, the size is 19×19×4mm, and the pair is a G Cr15 steel ball of Φ10mm. The load is 40N, the amplitude is 1mm, the frequency is 25Hz, and the running time is 30 minutes.

Detailed ways

Example 1:

Weigh the powdered reaction materials with mass percentages of nickel: 62.7, silicon: 10.0, chromium trioxide: 4.3, chromium trioxide: 14, aluminum: 9.0; dry mix the reaction materials in a ball mill for 10 hours; mix the Weigh 50g of a good material and press it into a green body with a pressure of 30MPa in a graphite mold; at the same time, weigh 5g of the igniter and press it into a block with a pressure of 30MPa; place the graphite mold with the reaction green body and igniter block on In the reaction vessel, flush the reaction vessel with an inert gas to remove the air in it; heat the blank to 200°C and keep it at this temperature for 1 hour; then remove the gas desorbed from the surface of the reaction material from the vessel, and then pass it into 5MPa inert gas; continue heating to about 260°C, the igniter initiates the reaction at this temperature; after the reaction is completed, the material is cooled to room temperature with the reaction container, and then taken out from the container.

The microhardness, flexural strength and wear rate of the materials are listed in Table 1.

Table 1 Hardness, flexural strength and wear rate of Ni ₃ Si-Cr composites Hardness (GPa) Bending strength (MPa) Wear rate (10 ^-14 m ³ .N ^-1 .m ^-1 ) Ni ₃ Si-Cr composite material 7.5 897 0.75

Example 2:

Take by weighing mass percent respectively, nickel: 62.5, silicon: 10.0, dichromium trioxide: 4.3, chromium trioxide: 14, aluminum: the powdery reaction material of 9.0; Activated carbon: the powdery reaction material of 0.2; Dry mix in a ball mill for 10 hours; weigh 50g of the mixed material and press it into a green body in a graphite mold with a pressure of 30MPa; at the same time, weigh 5g of the ignition agent and press it into a block with a pressure of 30MPa; put the reaction green body and The graphite mold of the igniter block is placed in the reaction vessel, and the reaction vessel is purged with an inert gas to remove the air; the billet is heated to 200°C and kept at this temperature for 1 hour; then the reaction material is removed from the vessel The gas desorbed on the surface is then fed with 5MPa inert gas; continue to heat to about 260°C, and the igniter initiates the reaction at this temperature; after the reaction is completed, the material is cooled to room temperature with the reaction container, and then taken out of the container.

The microhardness, flexural strength and wear rate of the materials are listed in Table 2.

Table 2 Hardness, flexural strength and wear rate of Ni ₃ Si-Cr composites containing C Hardness (GPa) Bending strength (MPa) Wear rate (10 ^-14 m ³ .N ^-1 .m ^-1 ) Ni ₃ Si-Cr Composite Material Containing C 9.8 1010 1.5

Claims (2)

1. A nickel-silicon-based intermetallic compound composite material, characterized in that the raw materials of the material are nickel 23.5-75.6, silicon 3.7-12.1, dichromium trioxide 1.9-11.3, chromium trioxide 6.3-37.3, aluminum 4.1-24.2, Activated carbon is composed of 0-1.2 (mass percentage). 2. The preparation method of the material according to claim 1, characterized in that the method comprises: nickel 23.5-75.6, silicon 3.7-12.1, dichromium trioxide 1.9-11.3, chromium trioxide 6.3-37.3, aluminum 4.1 to 24.2, activated carbon 0 to 1.2 Weigh the powdered reaction materials and mix them evenly, place them in a graphite mold and press them into a reaction embryo with a pressure of 10 to 30 MPa; place the graphite mold with the reaction embryo in the reaction container, Purge the reaction container with an inert gas to remove the air; heat the billet to 150 ° C ~ 200 ° C, and keep it at this temperature for 1 ~ 2 hours; then remove the gas desorbed from the surface of the reaction material from the container, and feed 3 ~ 10MPa inert gas; continue to heat to about 250 ~ 300 ° C, and initiate the reaction through the igniter. The igniter is a mixture composed of permanganate, magnesium powder, and sulfide. The components of permanganate: magnesium Powder: the mass ratio of sulfide is (1.0-2.0): (1.5-2.5): (1-2.0), and the weight percentage composition of igniter mixture accounts for 2～10% of total reaction material; The reaction vessel was cooled to room temperature.