阅读说明：本技术 TiC与石墨晶须增强高熵合金基复合材料及其制备方法 (TiC and graphite whisker reinforced high-entropy alloy-based composite material and preparation method thereof ) 是由 孙晓东 朱和国 兰利娟 于 2018-06-09 设计创作，主要内容包括：本发明公开了一种TiC与石墨晶须增强高熵合金基复合材料及其制备方法,该方法具体为：按照原料配比称取反应试样块体原料；按照体积分数制备增强体试块；装样：将块体原料与增强体试块装入高频感应熔炼炉中；抽真空；通入氩气；原位反应合成：控制电流,输出功率；保温：待反应结束后,保温10分钟；冷却出炉：将保温后的熔融液态合金倒入铜坩埚中冷却,取出,得到细晶内生性高熵合金基复合材料。本发明工艺采用感应熔炼的方式合成内生性颗粒与晶须增强高熵合金基复合材料,合成的复合材料增强体与基体之间界面结合良好,增强体均匀分布于高熵合金基体中。(The invention discloses a TiC and graphite whisker reinforced high-entropy alloy-based composite material and a preparation method thereof, wherein the method specifically comprises the following steps: weighing bulk raw materials of the reaction sample according to the raw material proportion; preparing a reinforcement test block according to the volume fraction; sample loading: loading the block raw material and the enhanced test block into a high-frequency induction smelting furnace; vacuumizing; introducing argon; in-situ reaction synthesis: controlling current and outputting power; and (3) heat preservation: after the reaction is finished, preserving the heat for 10 minutes; cooling and discharging: and pouring the molten liquid alloy after heat preservation into a copper crucible for cooling, and taking out to obtain the fine-grain endogenous high-entropy alloy-based composite material. The process adopts an induction melting mode to synthesize the endogenous particle and whisker reinforced high-entropy alloy matrix composite material, the interface between the synthesized composite material reinforcement and the matrix is well combined, and the reinforcement is uniformly distributed in the high-entropy alloy matrix.)

1. A preparation method of a TiC and graphite whisker reinforced high-entropy alloy-based composite material is characterized by comprising the following steps:

Sequentially adding Cu particles, a reinforcement test block, Ni particles, Fe particles and Co particles into a graphite crucible, and adjusting the heating rate,

Firstly, performing a heating reaction stage, adjusting output high-frequency current to 400A, and after the color of the crucible is changed, adjusting the output current to 350A; after 5 minutes, entering an enhancement body generation stage, carrying out in-situ reaction, and emitting heat to emit white light; finally, alloying is carried out, the output current is adjusted to be 610A, the temperature reaches 1500-2000 ℃, until metal particles are melted and alloyed, and the reinforcement is uniformly distributed in the high-entropy alloy matrix by induction self-stirring;

And (5) final heat preservation and cooling: and after the temperature is preserved for 5 minutes, cooling the reaction molten alloy by water to obtain the fine-grain high-entropy alloy-based composite material.

2. The TiC and graphite whisker reinforced high-entropy alloy-based composite material preparation method according to claim 1, wherein the metal particles of Fe, Co, Ni, Cu are weighed as follows: weighing high-purity Fe, Co, Ni and Cu metal particles, wherein the mixing ratio is adjusted according to the volume fraction of the reinforcement required by the target composite material.

3. The TiC and graphite whisker reinforced high-entropy alloy-based composite material preparation method according to claim 2, wherein the Fe, Co, Ni, Cu particles are weighed in an equimolar ratio.

4. The method for preparing TiC and graphite whisker reinforced high-entropy alloy-based composite material as defined in claim 1, wherein the method for preparing the reinforcement test block comprises the following steps: weighing high-purity Ti powder, C powder and Fe powder according to the volume fraction of the reinforcement, ball-milling, mixing, drying and pressurizing to obtain the reinforcement test block.

5. TiC and graphite whisker reinforced high-entropy alloy-based composite material according to claim 1, 2 or 4

The method is characterized in that the volume fraction of the reinforcement is 5-10% of the volume of the composite material.

6. Preparation of TiC and graphite whisker reinforced high-entropy alloy-based composite material according to claim 4

The method is characterized in that the mass ratio of the ball powder is 4: 1; the ball milling speed is 300 p.r.m; the ball milling time is 4 h.

7. Preparation of TiC and graphite whisker reinforced high-entropy alloy-based composite material according to claim 4

The method is characterized in that the drying temperature is 110-120 ℃; extruding the mixture to form a billet sample under the pressure of 180 MPa.

8. The method of claim 1, wherein the TiC and graphite whisker reinforced high-entropy alloy-based composite material is pretreated by sequentially adding a reinforcement test block and Fe, Co, Ni, Cu metal particles as follows: vacuumizing and introducing protective gas, vacuumizing to 2Pa by using a mechanical pump, and vacuumizing to 10 Pa by using a molecular pump^-4Pa; after the pressure is stabilized, introducing protective gas (argon) to maintain the pressure at 10^-1Pa。

9. The preparation method of TiC and graphite whisker reinforced high-entropy alloy-based composite material according to claim 1, wherein the high-temperature melting time is 9-11 minutes when the temperature is raised to 1800-2000 ℃.

10. A TiC and graphite whisker reinforced high-entropy alloy-based composite material synthesized by the method of any one of claims 1 to 9, characterized in that the composite material is synthesized by induction melting, wherein the high-entropy alloy of Fe-Co-Ni-Cu-Ti-C series is used as a matrix, and the high-strength wear-resistant composite material consists of granular TiC particles and graphite whiskers which are used as composite reinforcements.

Technical Field

The invention relates to a TiC and graphite whisker reinforced high-entropy alloy-based composite material and a preparation method thereof, belonging to the field of material preparation.

Background

The preparation method for preparing the high-entropy alloy-based composite material by the vacuum induction melting technology is characterized in that an induction heating mode is adopted, so that the composite material is prepared by heating and melting the preparation raw materials by self eddy current induction. The preparation method is simple to operate and convenient for industrial production. The defects of low heating efficiency and small preparation quantity of the traditional process are overcome, and the vacuum induction melting can be used for batch production of materials. The automatic control type adjustable heating time, heating power, heat preservation time, heat preservation power and cooling time are provided; greatly improves the yield and the repeatability of heating, and simplifies the operation technology of workers. The high-entropy alloy-based composite material prepared by the method has high strength, high wear resistance and corrosion resistance. In the process of forming the high-entropy alloy, a nano Cu phase can be formed between crystals, so that the yield strength of the material can be increased, and a certain toughening effect on the material can be achieved. The prepared high-entropy alloy-based composite material also has excellent performances in the aspects of conductivity and magnetic permeability. In addition, the high-entropy alloy-based composite material has good application prospects in the aspects of impact-resistant pieces and high-temperature-resistant dies.

Literature (Cheng J, Liu D, Liang X, et al. evolution of microstructure and mechanical properties of in situ synthesized TiC-TiB 2/CoCrCuFeNi high order coatings [ J].Surface&In Coatings Technology,2015,281(7):109-116), TiC-TiB is prepared by vacuum arc melting Technology₂The melting process of the/CoCrCuFeNi composite reinforcement high-entropy alloy-based composite material is high in energy consumption, the quantity of prepared samples has certain limitation, only a small quantity of samples for electric arc heating can be prepared, the samples cannot be used for batch production, and the single particle reinforcing effect is poorer than the particle and whisker composite reinforcing effect. Luxinhua et al prepared FeCrCoNiCuTi/TiC high-entropy alloy composite material by adopting a synthesis method of mixing powder blocks and metal blocks, and the prepared sample tissue reinforcement body was not uniformly distributed in a matrix, and the interface bonding performance was poor, although the wear resistance of the sample was improved, the yield strength was reduced.

Disclosure of Invention

The invention aims to provide a TiC and graphite whisker reinforced high-entropy alloy-based composite material and a preparation method thereof.

the technical solution for realizing the purpose of the invention is as follows:

The high-entropy alloy-based composite material is an endogenous type, takes FeCoNiCu high-entropy alloy as a matrix phase and Takes (TiC)&graphite-whiskers)_xAs reinforcing phase, is noted as (TiC)&graphite-whiskers)_x/(FeCoNiCu)_1-xand x is 0.05 to 0.1.

the method for preparing the endogenous high-entropy alloy-based composite material comprises the following steps:

Sequentially adding Cu particles, a reinforcement test block, Ni particles, Fe particles and Co particles into a graphite crucible, and adjusting the heating rate,

Firstly, performing a heating reaction stage, adjusting output high-frequency current to 400A, and after the color of the crucible is changed, adjusting the output current to 350A; after 5 minutes, entering an enhancement body generation stage, carrying out in-situ reaction, and emitting heat to emit white light; finally, alloying is carried out, the output current is adjusted to be 610A, the temperature reaches 1500-2000 ℃, until metal particles are melted and alloyed, and the reinforcement is uniformly distributed in the high-entropy alloy matrix by induction self-stirring;

And (5) final heat preservation and cooling: and after the temperature is preserved for 5 minutes, cooling the reaction molten alloy by water to obtain the fine-grain high-entropy alloy-based composite material.

Further, the metal particles of Fe, Co, Ni, Cu are weighed as follows: weighing high-purity Fe, Co, Ni and Cu metal particles, wherein the mixing ratio is adjusted according to the volume fraction of the reinforcement required by the target composite material.

and further weighing the Fe, Co, Ni and Cu particles according to the equal molar ratio.

Further, the method for preparing the reinforcement test block comprises the following steps: weighing high-purity Ti powder, C powder and Fe powder according to the volume fraction of the reinforcement, ball-milling, mixing, drying and pressurizing to obtain the reinforcement test block.

Further, the volume fraction of the reinforcement is 5% -10% of the volume of the composite material.

Further, the mass ratio of the ball powder is 4: 1; the ball milling speed is 300 p.r.m; the ball milling time is 4 h.

Further, the drying temperature is 110-120 ℃; extruding the mixture to form a billet sample under the pressure of 180 MPa.

Further, the reinforcement test block and the Fe, Co, Ni and Cu metal particles are pretreated as follows before being sequentially added: vacuumizing to 2Pa by using a mechanical pump, and then vacuumizing to 10 Pa by using a molecular pump^-4Pa; after the pressure is stabilized, introducing protective gas (argon) to maintain the pressure at 10^-1Pa。

Further, the high-temperature smelting time is 9-11 minutes when the temperature is raised to 1800-2000 ℃.

Compared with the prior art, the invention has the following remarkable advantages: (1) the method has the advantages of lower synthesis activation energy than that of the conventional heating mode by using induction melting, lower reaction temperature, quick reaction, simple process operation, safety, reliability, energy conservation, time conservation and environmental friendliness. (2) The invention has the advantages of fast heating rate, short reaction process, inhibition of texture coarsening and dendrite segregation, obvious tissue refinement, self-stirring due to fast reaction heat release, effective purification of matrix due to high heat generated by reaction, and contribution to improving the performance of the material. (3) The high-entropy alloy matrix phase generated by the reaction of the invention has amplitude modulation decomposition and lattice distortion effect, thereby preventing the material from stress relaxation deformation caused by lattice movement. (4) The high-entropy alloy-based composite material generated by the reaction of the invention has a single face-centered cubic structure, has good material strength and shaping property, has a simple structure, does not generate a complex intermetallic compound phase, and is organized into a regular single-phase solid solution structure.

Drawings

Fig. 1 is an XRD diffractogram of the high-entropy alloy-based composite material of example 1 of the present invention.

FIG. 2 is a SEM (scanning electron microscope) image of the matrix of the high-entropy alloy-based composite material in example 1 of the invention.

Fig. 3 a, B, C are EDS spectra of the corresponding regions a, B, C of fig. 2.

In fig. 4, a and b are TEM scans of the high-entropy alloy-based composite material of example 1 of the present invention, and fig. 4c is a diffraction spot diagram of the TiC phase in the high-entropy alloy-based composite material of example 1 of the present invention.

FIG. 5 is an SEM scanning electron micrograph of the high-entropy alloy-based composite material of example 2 of the invention.

FIG. 6 is a graph comparing the tensile stress strain curves of examples 1 and 2 with FeCoNiCu high entropy alloy.

Detailed Description

The invention will be further explained with reference to the following examples and drawings