阅读说明：本技术 一种低熔点Bi基液态金属及其制备方法 (Bi-based liquid metal with low melting point and preparation method thereof ) 是由 王利民 冯士东 关子横 杜前湫 于 2021-09-06 设计创作，主要内容包括：本发明公开了一种低熔点Bi基液态金属及其合金化制备方法,其熔点温度约为40℃,所述液态金属由以下质量分数的组分组成：铋38.5～41％；铟16.5～18％；铅21～23％；锡10～11％；镉7～9％；镓1～5％。本发明通过基于合金化法的封管法制备六元Bi基液态金属BiInPbSnCdGa,通过微添加单质金属元素的方式对组分和比例进行微调整来降低液态金属的熔点温度,组分清晰,制备方法简单,只需简单抽真空封管后,熔炼使之均匀熔化即可,抽真空封管可保证液态金属的各组分的原始配比与熔样完成后的元素占比的一致性,保证液态金属的良好性能。(The invention discloses a low-melting-point Bi-based liquid metal and an alloying preparation method thereof, wherein the melting point temperature is about 40 ℃, and the liquid metal comprises the following components in percentage by mass: 38.5-41% of bismuth; 16.5-18% of indium; 21-23% of lead; 10-11% of tin; 7-9% of cadmium; 1-5% of gallium. According to the invention, the hexahydric Bi-based liquid metal BiInPbSnCdGa is prepared by a tube sealing method based on an alloying method, the melting point temperature of the liquid metal is reduced by micro-adjusting the components and the proportion in a mode of micro-adding a simple substance metal element, the components are clear, the preparation method is simple, the melting is carried out to uniformly melt the components after the tube sealing is simply carried out by vacuumizing, the consistency of the original proportion of each component of the liquid metal and the proportion of the element after the sample melting is finished can be ensured by vacuumizing the tube sealing, and the good performance of the liquid metal is ensured.)

1. A low melting Bi-based liquid metal, characterized in that the liquid metal consists of, in mass fractions:

38.5-41% of bismuth; 16.5-18% of indium; 21-23% of lead; 10-11% of tin; 7-9% of cadmium; 1-5% of gallium.

2. The low melting point Bi-based liquid metal of claim 1, wherein the liquid metal consists of, in mass fractions:

40-41% of bismuth; 17-18% of indium; 22-23% of lead; 10-11% of tin; 8-9% of cadmium; 1.1% of gallium.

3. The low melting point Bi-based liquid metal of claim 1, wherein the liquid metal consists of, in mass fractions:

39-40% of bismuth; 17-18% of indium; 21-22% of lead; 10-11% of tin; 8-9% of cadmium; and 2% of gallium.

4. The low melting point Bi-based liquid metal of claim 1, wherein the liquid metal consists of, in mass fractions:

39-40% of bismuth; 17-18% of indium; 21-22% of lead; 10-11% of tin; 7-8% of cadmium; and 3% of gallium.

5. The low melting point Bi-based liquid metal of claim 1, wherein the liquid metal consists of, in mass fractions:

38.5 to 39.5 percent of bismuth; 16.5-17.5% of indium; 21-22% of lead; 10-11% of tin; 7-8% of cadmium; 4% of gallium.

6. The low melting point Bi-based liquid metal of claim 1, wherein the liquid metal consists of, in mass fractions:

38.5 to 39.5 percent of bismuth; 16.5-17.5% of indium; 21-22% of lead; 10-11% of tin; 7-8% of cadmium; and 5% of gallium.

7. The method for producing a low-melting-point Bi-based liquid metal according to any one of claims 1 to 6, comprising the steps of:

(1) cutting raw materials of each component of the low-melting-point Bi-based liquid metal into samples according to the mixture ratio and then loading the samples into a reaction vessel;

(2) vacuumizing the reaction container filled with the cut sample in the step (1), filling inert protective gas, and sintering an opening of the reaction container to realize tube sealing operation;

(3) preheating: heating the reaction container after the tube sealing in the step (2) to 500-700 ℃ until the sample in the reaction container is completely melted to obtain a melt sample;

(4) and (4) carrying out ultrasonic dispersion treatment on the molten sample in the step (3) until the molten sample in the reaction container is uniform, thus obtaining the liquid metal.

8. The method for producing a low-melting-point Bi-based liquid metal according to claim 7, wherein in the step (1), the sequence of cutting the raw materials of the components and placing the cut raw materials in the reaction vessel is as follows: the cadmium cut sample is put in, and finally the gallium cut sample is put in.

9. The method for producing a low-melting-point Bi-based liquid metal as claimed in claim 7, wherein in the step (2), the degree of vacuum of the vacuum treatment is-0.1 to 0 Pa;

preferably, in the step (4), the temperature of the ultrasonic dispersion treatment is controlled to be 70-100 ℃, the ultrasonic frequency is controlled to be 25-50 KHz, and the ultrasonic power is 50-80W.

10. The method according to claim 7, wherein the melting point of the low-melting-point Bi-based liquid metal is 40 to 40.6 ℃.

Technical Field

The invention relates to the technical field of alloy materials, in particular to a low-melting-point Bi-based liquid metal and a preparation method thereof.

Background

Bismuth (B)i) The base liquid metal is a novel functional material with very unique physical and chemical properties, has the properties of strong electrical conductivity, high thermal conductivity, safety, no toxicity and the like, and has the low melting point characteristic which is not possessed by the conventional high-melting-point metal material. The unique sensing capability, motion capability, deformation capability, self-repairing capability and performance adjustability bring subversion to the development of the fields of energy sources, advanced manufacturing, national defense and military, flexible robots, biomedical health and the like. At present, the Bi-based liquid metal is widely applied to the fields of 3D printing forming, waste heat recovery, solar energy, thermal interface materials, microfluid and the like, and can greatly improve the product and the technical performance. However, there are some technical bottlenecks that restrict the development of Bi-based liquid metals, such as melting point and viscosity. Among them, five-element eutectic alloys Bi are described in the literature (White, Guy Kendall; Meepon, Philip J. (2002), Experimental techniques in low-temperature physics, Clarendon. pp.207. ISBN 9780198514275.)_40.76In_18.16Pb_22.17Sn_10.68Cd_8.22And a six-membered alloy Bi_40.3In_17.7Pb_22.2Sn_10.7Cd_8.1Tl_1.1The melting points of the two alloys are 46.5 ℃ and 41.5 ℃, respectively, and the applicant actually measures that the melting points of the two alloys are as follows: 48.11 ℃ and 41.9 ℃. Obviously, the melting point of the current Bi-based liquid metal is far from being suitable for various complicated conditions, so the development of the Bi-based liquid metal with low melting point is urgent.

Disclosure of Invention

Aiming at the technical problems, the invention provides a low-melting-point Bi-based liquid metal prepared by an alloying method, and the liquid metal with a low melting point is explored by controlling the component proportion and the sample preparation method, wherein the melting point temperature of the liquid metal is about 40 ℃, the melting point of the liquid metal is obviously reduced, the service interval of the liquid metal in a medium-temperature section is expanded, and the application of the liquid metal in the medium-temperature field is expanded.

In order to achieve the purpose, the invention adopts the technical scheme that:

the invention provides a low-melting-point Bi-based liquid metal, which comprises the following components in percentage by mass:

38.5-41% of bismuth; 16.5-18% of indium; 21-23% of lead; 10-11% of tin; 7-9% of cadmium; 1-5% of gallium.

Preferably, the liquid metal consists of the following components in mass fraction: 40-41% of bismuth; 17-18% of indium; 22-23% of lead; 10-11% of tin; 8-9% of cadmium; 1.1% of gallium.

Preferably, the liquid metal consists of, in mass fraction:

39-40% of bismuth; 17-18% of indium; 21-22% of lead; 10-11% of tin; 8-9% of cadmium; and 2% of gallium.

Preferably, the liquid metal consists of the following components in mass fraction:

39-40% of bismuth; 17-18% of indium; 21-22% of lead; 10-11% of tin; 7-8% of cadmium; and 3% of gallium.

Preferably, the liquid metal consists of the following components in mass fraction:

38.5 to 39.5 percent of bismuth; 16.5-17.5% of indium; 21-22% of lead; 10-11% of tin; 7-8% of cadmium; 4% of gallium.

Preferably, the liquid metal consists of the following components in mass fraction:

38.5 to 39.5 percent of bismuth; 16.5-17.5% of indium; 21-22% of lead; 10-11% of tin; 7-8% of cadmium; and 5% of gallium.

In the technical scheme of the invention, the melting point of the liquid metal is reduced along with the reduction of the gallium proportion.

The second aspect of the present invention provides a method for preparing the low-melting-point Bi-based liquid metal, comprising the steps of:

(1) cutting the raw materials of each component of the low-melting-point Bi-based liquid metal according to the mixture ratio and quality, and then loading the cut samples into a reaction vessel;

(2) vacuumizing the reaction container filled with the cut sample in the step (1), filling inert protective gas, and sintering an opening of the reaction container to realize tube sealing operation;

(3) preheating: heating the reaction container after the tube sealing in the step (2) to 500-700 ℃ until the sample in the reaction container is completely melted to obtain a melt sample;

(4) and (4) carrying out ultrasonic dispersion treatment on the molten sample in the step (3) until the molten sample in the reaction container is uniform, thus obtaining the liquid metal.

In a preferred embodiment, in step (1), the raw material of the low-melting-point Bi-based liquid metal component is subjected to a cleaning and drying treatment after removing surface scales by sanding. The processed component raw materials are cut into samples according to the mass ratio and then are filled into a reaction container.

Preferably, the order of placing the cut samples into the reaction vessel is: cadmium is prepared firstly, and because the cadmium is easily heated to generate brown yellow smoke to cause loss (presumably cadmium oxide), the cadmium is placed at the bottommost part of the reaction vessel to avoid excessive loss of cadmium element. Secondly, bismuth, indium, lead and tin are put into the sample cutter in any order, and finally gallium is put into the sample cutter, because gallium is easy to oxidize in the air, and the sample preparation is completed, and the sample melting and tube sealing treatment is immediately carried out, so that the excessive loss of gallium elements is avoided.

Preferably, in the step (2), the vacuum degree of the vacuumizing treatment is-0.1-0 Pa;

preferably, in the step (4), the temperature of the ultrasonic dispersion treatment is controlled to be 70-100 ℃, the ultrasonic frequency is controlled to be 20-50 KHz, and the ultrasonic power is 50-80W.

In some specific embodiments, the filling of the inert shielding gas after the vacuum-pumping treatment is performed by: pumping the vacuum degree in the reaction container filled with the sample to-0.1-0 pa, pumping to-0.1-0 pa again after filling inert protective gas for gas washing, repeatedly washing for 3 times, and finally filling the inert protective gas.

In the technical scheme of the invention, a tube sealing method is adopted to vacuumize the reaction container and fill inert protective gas into the reaction container, and then the reaction container is sintered, so that the vacuum degree in the reaction container is fully ensured, and the wall sticking phenomenon of sample cutting in the sample melting process can be avoided, thereby ensuring that the sample is completely melted uniformly, avoiding the manual operation error in the experimental process, and ensuring the consistency of the original proportion of each component of liquid metal and the element proportion after the sample melting is finished.

In the technical scheme of the invention, the melting point of the low-melting-point Bi-based liquid metal is 40-40.6 ℃.

The technical scheme has the following advantages or beneficial effects:

the invention prepares the hexahydric Bi-based liquid metal BiInPbSnCdGa with low melting point on the basis of a quinary alloy BiInPbSnCd and 1-5% of Ga, and the melting point of the hexahydric Bi-based liquid metal BiInPbSnCdGa is about 40 ℃. The invention reduces the melting point temperature of the liquid metal by micro-adjusting the components and the proportion by micro-adding simple substance metal elements, has clear components and simple preparation process, only needs simple vacuum tube sealing and then smelting to uniformly melt the components, can ensure the consistency of the original proportion of each component of the liquid metal and the proportion of the elements after sample melting is finished, and is a preparation method for efficiently reducing the melting point and ensuring the good performance of the liquid metal.

Drawings

FIG. 1 is a DSC melting point test result of the five-membered liquid metal system in comparative example 1;

FIG. 2 shows the liquid metal (Bi) in comparative example 3_40.7In_17.9Pb_22.4Sn_10.8Cd_8.2)₉₉DSC melting point test result chart of + 1% Ga (vacuum pumping method);

FIG. 3 shows the liquid metal (Bi) in comparative example 2_40.7In_17.9Pb_22.4Sn_10.8Cd_8.2)₉₉DSC melting point test result chart of + 1% Zn liquid metal;

FIG. 4 shows the liquid metal (Bi) in example 1_40.7In_17.9Pb_22.4Sn_10.8Cd_8.2)₉₉DSC melting point test result chart of + 1% Ga (tube sealing method);

FIG. 5 shows the liquid metal (Bi) in example 2_40.7In_17.9Pb_22.4Sn_10.8Cd_8.2)₉₈DSC melting point test result chart of + 2% Ga (tube sealing method);

FIG. 6 shows the liquid metal (Bi) in example 3_40.7In_17.9Pb_22.4Sn_10.8Cd_8.2)₉₇DSC melting point of + 3% Ga (tube sealing method) test junctionFruit graph;

FIG. 7 shows the liquid metal (Bi) in example 4_40.7In_17.9Pb_22.4Sn_10.8Cd_8.2)₉₆DSC melting point of + 4% Ga (tube sealing method) test result chart;

FIG. 8 shows the liquid metal (Bi) in example 5_40.7In_17.9Pb_22.4Sn_10.8Cd_8.2)₉₅DSC melting point of + 5% Ga (tube sealing method).

Detailed Description

The following examples are only a part of the present invention, and not all of them. Thus, the detailed description of the embodiments of the present invention provided below is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the invention without making creative efforts, belong to the protection scope of the invention.

The invention aims to provide a Bi-based liquid metal with a low melting point prepared based on alloying, wherein the liquid metal comprises the following components in percentage by mass: 38.5-41% of bismuth; 16.5-18% of indium; 21-23% of lead; 10-11% of tin; 7-9% of cadmium; 1-5% of gallium, and the melting point of the gallium is 40-40.6 ℃.

In some specific embodiments, the low melting point Bi-based liquid metal comprises the following components: the mass fraction of the bismuth element is 40-41%, preferably 40.3%, 17-18% of indium element, preferably 17.7%, 22-23% of lead element, preferably 22.2%, 10-11% of tin element, preferably 10.7%, 8-9% of cadmium element, preferably 8.1%, and 1% of gallium element.

In some specific embodiments, the liquid metal comprises the following components: 39-40% of bismuth element, preferably 39.89%, 17-18% of indium element, preferably 17.52%, 21-22% of lead element, preferably 21.98%, 10-11% of tin element, preferably 10.59%, 8-9% of cadmium element, preferably 8.02%, and 2% of gallium element.

In some specific embodiments, the liquid metal comprises the following components: 39-40% of bismuth element, preferably 39.49% of indium element, 17-18% of indium element, preferably 17.34% of lead element, preferably 21.75% of tin element, 10-11% of tin element, preferably 10.48% of cadmium element, 7-8% of cadmium element, preferably 7.94% of gallium element.

In some specific embodiments, the liquid metal comprises the following components: 38.5-39.5% of bismuth, preferably 39.08%, 16.5-17.5% of indium, preferably 17.16%, 21-22% of lead, preferably 21.53%, 10-11% of tin, preferably 10.38%, 7-8% of cadmium, preferably 7.85%, and 4% of gallium.

In some specific embodiments, the liquid metal comprises the following components: 38.5-39.5% of bismuth element, preferably 38.67%, 16.5-17.5% of indium element, preferably 17%, 21-22% of lead element, preferably 21.28%, 10-11% of tin element, preferably 10.26%, 7-8% of cadmium element, preferably 7.79% and 5% of gallium element.

The preparation method of liquid metal in the following examples and comparative examples comprises the following steps:

(1) polishing the raw materials for preparing the liquid metal by using sand paper to remove oxide skin, putting the raw materials into a sample bag, adding absolute ethyl alcohol, and cleaning by using an ultrasonic cleaner;

(2) drying the cleaned raw materials of each component, wiping the raw materials by using dust-free paper, cutting the sample according to the specified proportioning quality (the total weight of the sample is 6g), putting the cadmium cut sample in the sample, and putting the cadmium cut sample and the gallium cut sample in a long test tube (the inner diameter is 9mm, the outer diameter is 12mm, and the height is 29cm) in sequence;

(3) the test tube with the sample is vacuumized by a tube sealing machine (Partulab MRVS-1002; purchased from Bailibo science and technology (China)), and the operation is as follows: pumping the vacuum degree in the test tube to about-0.1-0 Pa, closing an air pumping valve at a vacuum pumping side, opening an air inlet valve at a high-purity argon side, displaying that the air pressure in the test tube rises, closing an air inlet valve after 5-6S, performing vacuum pumping operation again, repeatedly washing for 3 times, taking out impurity air in the tube to the maximum degree, and filling inert protective gas; then, opening a hydrogen production machine to prepare hydrogen, and sintering the test tube by using a hydrogen flame gun to realize tube sealing operation; the purpose of adopting the tube sealing machine is to realize vacuum pumping and inert gas filling, and finally the tube sealing is realized by hydrogen flame gun sintering.

(4) Preheating: heating and vibrating the reaction container by using an alcohol lamp (the heating temperature of the alcohol lamp is 500-;

(5) and (3) taking out the reaction container obtained in the step (4), placing the reaction container in a temperature-controlled ultrasonic machine, setting the temperature to be 70-100 ℃, turning on an ultrasonic switch (the ultrasonic frequency is 25-50 KHz, and the ultrasonic power is 50-80W), and keeping the time for 0.5-1 hour until the sample melting in the reaction container is uniform, thus obtaining the liquid metal.

In order to test whether all elements in the sample after sample melting are uniformly fused or not, the upper part and the lower part of the sample are respectively sampled to carry out melting point test, and the sample can be considered to be uniformly melted when the temperature difference of the melting points is within +/-0.5 ℃.

In the components of the six-element alloy BiInPbSnCd, the enthalpy of mixing between Ga and Bi, In, Pb, Sn and Cd is non-negative, five metals of Bi, In, Sn, Pb and Cd have lower melting points, and mostly form non-negative mixed heat, the acting force between atoms is not strong, so that a solid solution phase is favorably formed, and a compound with a higher melting point is unfavorable to form. In addition, the formula Δ G_mix＝ΔH_mix-TS_mixShown as (Δ G)_mixIs Gibbs free energy, Δ H_mixIs the enthalpy of mixing, S_mixAs entropy of mixing): three key factors of the magnitude of the free energy are the enthalpy of mixing, the entropy of mixing and the temperature. The mixing entropy and mixing enthalpy are mutually restricted, and the dominant factor determines whether the alloy forms a solid solution phase or an intermetallic compound. Meanwhile, it is known from Boltzmann formula Δ S ═ rln (n) (where R is a gas constant): the more constituent elements, the greater the number of atoms n, the greater the degree of disorder, and the greater the entropy. Therefore, the higher the entropy value of the alloy, the lower the free energy, thereby promoting mutual solubility of elements, simplifying the structure of the alloy, forming a simple body-centered cubic or face-centered cubic solid solution, and further improving the stability of the alloySuppressing the formation of intermetallic compounds. According to the invention, the hexabasic alloy liquid metal is prepared by alloying the micro-additive elements by utilizing the non-negative mixing enthalpy and the high entropy effect among the elements, the melting point is successfully reduced, and the melting point of the liquid metal is reduced to about 40 ℃.

In the following examples, the melting point of the liquid metal was tested as follows: and taking out the liquid metal sample after sample melting, and performing platen treatment on the core part of the sample to prepare a DSC test sample. In the experimental process, about 10mg of samples are cut each time to perform DSC melting point test. For the crucible used for the DSC test, an aluminum platen was selected. Due to the corrosion effect of gallium on aluminum, a part of a sample to be measured is cut and pressed before an experiment, a pressed aluminum disc is placed in a vacuum drying oven at 60 ℃ for heat preservation for 1 hour, and the Al disc is not corroded basically in the process.

During low-temperature DSC test, the initial temperature is set to 30 ℃, the temperature is kept for 1min, the temperature is increased to 60 ℃ at the temperature rising rate of 5 ℃/min, the temperature is kept for 1min, and the temperature is decreased to 30 ℃ at the temperature decreasing rate of 5 ℃/min. After the test was finished, Onset temperature was chosen as the melting temperature of the sample by software analysis.

Example 1

In this example, the liquid metal is (Bi)_40.7In_17.9Pb_22.4Sn_10.8Cd_8.2)₉₉+ 1% of Ga (mass percentage, bismuth 40.3%, indium 17.7%, lead 22.2%, tin 10.7%, cadmium 8.1%, gallium 1%), the preparation method comprising the following steps:

(1) polishing the raw materials for preparing the liquid metal by using sand paper to remove oxide skin, putting the raw materials into a sample bag, adding absolute ethyl alcohol, and cleaning by using an ultrasonic cleaner;

(2) drying the cleaned alloy raw materials, wiping the cleaned alloy raw materials by using dust-free paper, cutting samples according to the specified proportioning quality (the total weight of the samples is 6g), and then loading the samples into a long test tube (the inner diameter is 9mm, the outer diameter is 12mm, and the height is 29cm) according to the sequence of Cd, Bi, In, Pb, Sn and Ga;

(3) vacuumizing the test tube with the sample by using a tube sealing machine, wherein the vacuumizing in the tube sealing machine needs 5-6 min until-0.1 Pa is obtained by pumping, then opening a hydrogen production machine to prepare hydrogen, and sintering the opening of the test tube by using a hydrogen flame gun to realize tube sealing operation;

(4) preheating: heating and shaking the test tube by using an alcohol lamp (500-700 ℃), until the sample in the test tube is completely melted;

(5) and (4) taking out the test tube obtained in the step (4), placing the test tube in a temperature-controlled ultrasonic machine, setting the temperature to be 80 ℃, turning on an ultrasonic switch (the ultrasonic frequency is 40KHz, the ultrasonic power is 80W), and keeping the time for 0.75 hour until the sample melting in the test tube is uniform, thus obtaining the liquid metal. Melting point temperature 40.15 ℃ by DSC test (see FIG. 4).

Example 2

In this example, the liquid metal is (Bi)_40.7In_17.9Pb_22.4Sn_10.8Cd_8.2)₉₈+ 2% of Ga, the specific ratio is: bi_{39.8 9}In_17.54Pb_21.95Sn_10.58Cd_8.04Ga₂(ii) a The preparation method of the system (mass percent, bismuth 39.89%, indium 17.54%, lead 21.95%, tin 10.58%, cadmium 8.04%, gallium 2%) comprises the following steps:

(1) polishing an alloy raw material for preparing liquid metal by using abrasive paper to remove oxide skin, putting the alloy raw material into a sample bag, adding absolute ethyl alcohol, and cleaning by using an ultrasonic cleaner;

(2) drying the cleaned alloy raw materials, wiping the cleaned alloy raw materials by using dust-free paper, cutting samples according to the specified proportioning quality (the total weight of the samples is 6g), and then loading the samples into a long test tube (the inner diameter is 9mm, the outer diameter is 12mm, and the height is 29cm) according to the sequence of Cd, Bi, In, Pb, Sn and Ga;

(3) vacuumizing the test tube with the sample by using a tube sealing machine, wherein the vacuumizing in the tube sealing machine needs 5-6 min until-0.05 Pa is obtained by pumping, then opening a hydrogen production machine to prepare hydrogen, and sintering the test tube by using a hydrogen fire gun to realize tube sealing operation;

(4) preheating: heating and shaking the test tube by using an alcohol lamp (500-700 ℃), until the sample in the test tube is completely melted;

(5) and (4) taking out the test tube obtained in the step (4), placing the test tube in a temperature-controlled ultrasonic machine, setting the temperature to be 70 ℃, turning on an ultrasonic switch (the ultrasonic frequency is 40KHz, the ultrasonic power is 80W), and keeping the time for 1 hour until the sample melting in the test tube is uniform, thus obtaining the liquid metal. Melting point temperature 40.18 ℃ by DSC test (see FIG. 5).

Example 3

In this example, the liquid metal is (Bi)_40.7In_17.9Pb_22.4Sn_10.8Cd_8.2)₉₇+ 3% of Ga, the specific ratio is: bi_{39.4 8}In_17.36Pb_21.73Sn_10.48Cd_7.95Ga₃(ii) a The preparation method of the system (mass percent, bismuth 39.48%, indium 17.36%, lead 21.73%, tin 10.48%, cadmium 7.95%, gallium 3%) comprises the following steps:

(1) polishing an alloy raw material for preparing liquid metal by using abrasive paper to remove oxide skin, putting the alloy raw material into a sample bag, adding absolute ethyl alcohol, and cleaning by using an ultrasonic cleaner;

(2) drying the cleaned alloy raw materials, wiping the cleaned alloy raw materials by using dust-free paper, cutting samples according to the specified proportioning quality (the total weight of the samples is 6g), and then loading the samples into a long test tube (the inner diameter is 9mm, the outer diameter is 12mm, and the height is 29cm) according to the sequence of Cd, Bi, In, Pb, Sn and Ga;

(3) vacuumizing the test tube with the sample by using a tube sealing machine, wherein the vacuumizing in the tube sealing machine needs 5-6 min until the pressure is 0Pa, then opening a hydrogen production machine to prepare hydrogen, and sintering the test tube by using a hydrogen fire gun to realize tube sealing operation;

(4) preheating: heating and shaking the test tube by using an alcohol lamp (500-700 ℃), until the sample in the test tube is completely melted;

(5) and (4) taking out the test tube obtained in the step (4), placing the test tube in a temperature-controlled ultrasonic machine, setting the temperature to be 100 ℃, turning on an ultrasonic switch (the ultrasonic frequency is 40KHz, the ultrasonic power is 80W), and keeping the time for 1 hour until the sample melting in the test tube is uniform, thus obtaining the liquid metal. Melting point temperature 40.38 ℃ by DSC test (see FIG. 6).

Example 4

In this example, the liquid metal is (Bi)_40.7In_17.9Pb_22.4Sn_10.8Cd_8.2)₉₆+ 4% of Ga, the specific ratio is: bi_{39.0 7}In_17.18Pb_21.50Sn_10.37Cd_7.88Ga₄(ii) a The preparation method of the system (mass percent, bismuth 39.07%, indium 17.18%, lead 21.50%, tin 10.37%, cadmium 7.88%, gallium 4%) comprises the following steps:

(1) polishing an alloy raw material for preparing liquid metal by using abrasive paper to remove oxide skin, putting the alloy raw material into a sample bag, adding absolute ethyl alcohol, and cleaning by using an ultrasonic cleaner;

(2) drying the cleaned alloy raw materials, wiping the cleaned alloy raw materials by using dust-free paper, cutting samples according to the specified proportioning quality (the total weight of the samples is 6g), and then loading the samples into a long test tube (the inner diameter is 9mm, the outer diameter is 12mm, and the height is 29cm) according to the sequence of Cd, Bi, In, Pb, Sn and Ga;

(3) vacuumizing the test tube with the sample by using a tube sealing machine, wherein the vacuumizing in the tube sealing machine needs 5-6 min until the vacuumizing is about-0.1-0 Pa, then opening a hydrogen production machine to prepare hydrogen, and sintering the test tube by using a hydrogen fire gun to realize the tube sealing operation;

(4) preheating: heating and shaking the test tube by using an alcohol lamp (500-700 ℃), until the sample in the test tube is completely melted;

(5) and (3) taking out the test tube obtained in the step (4), placing the test tube in a temperature-controlled ultrasonic machine, setting the temperature to be 70-100 ℃, turning on an ultrasonic switch (the ultrasonic frequency is 40KHz, the ultrasonic power is 80W), and keeping the time for 0.5-1 hour until the sample melting in the test tube is uniform, thus obtaining the liquid metal. Melting point temperature 40.21 ℃ by DSC test (see FIG. 7).

Example 5

In this example, the liquid metal is (Bi)_40.7In_17.9Pb_22.4Sn_10.8Cd_8.2)₉₅+ 5% of Ga, the specific ratio is: bi_{38.6 7}In_17..0Pb_21.28Sn_10.26Cd_7.79Ga₅(ii) a The preparation method of the system (mass percent, bismuth 38.67%, indium 17.0%, lead 21.28%, tin 10.26%, cadmium 7.79%, gallium 5%) comprises the following steps:

(1) polishing an alloy raw material for preparing liquid metal by using abrasive paper to remove oxide skin, putting the alloy raw material into a sample bag, adding absolute ethyl alcohol, and cleaning by using an ultrasonic cleaner;

(2) drying the cleaned alloy raw materials, wiping the cleaned alloy raw materials by using dust-free paper, cutting samples according to the specified proportioning quality (the total weight of the samples is 6g), and then loading the samples into a long test tube (the inner diameter is 9mm, the outer diameter is 12mm, and the height is 29cm) according to the sequence of Cd, Bi, In, Pb, Sn and Ga;

(3) vacuumizing the test tube with the sample by using a tube sealing machine, wherein the vacuumizing in the tube sealing machine needs 5-6 min until the vacuumizing is about-0.1-0 Pa, then opening a hydrogen production machine to prepare hydrogen, and sintering the test tube by using a hydrogen fire gun to realize the tube sealing operation;

(4) preheating: heating and shaking the test tube by using an alcohol lamp (500-700 ℃), until the sample in the test tube is completely melted;

(5) and (3) taking out the test tube obtained in the step (4), placing the test tube in a temperature-controlled ultrasonic machine, setting the temperature to be 70-100 ℃, turning on an ultrasonic switch (the ultrasonic frequency is 40KHz, the ultrasonic power is 80W), and keeping the time for 0.5-1 hour until the sample melting in the test tube is uniform, thus obtaining the liquid metal. Melting point temperature 40.56 ℃ by DSC test (see FIG. 8).

In order to verify that the five-membered parent BiInPbSnCd + x% Ga has a larger breakthrough in the aspect of melting point reduction, Bi is selected_40.76In_18.16Pb_22.17Sn_10.68Cd_8.22The quinary alloy (comparative example 1) was compared, and (Bi) was selected to verify that the composition of + x% Ga is more advantageous than that of + x% Zn in the invention in lowering the melting point_40.7In_17.9Pb_22.4Sn_10.8Cd_8.2)₉₉+ 1% Zn (comparative example 2) for comparison. Finally, to verify that the tube sealing method used in the present invention melts samples more uniformly, (Bi) was chosen_40.7In_17.9Pb_22.4Sn_10.8Cd_8.2)₉₉+ 1.1% Ga (comparative example 3, evacuated method) was used for comparison.

Comparative example 1

The liquid metal in this comparative example is Bi_40.76In_18.16Pb_22.17Sn_10.68Cd_8.23The preparation method of the system (mass percent, bismuth 40.76%, indium 18.16%, lead 22.17%, tin 10.68%, cadmium 8.23%) is the same as that in example 1. Warp beamDSC (see FIG. 1), melting point temperature 48.11 ℃.

Comparative example 2

The liquid metal in this comparative example is (Bi)_40.7In_17.9Pb_22.4Sn_10.8Cd_8.2)₉₉+ 1% of Zn, system (mass%, bismuth 40.3%, indium 17.7%, lead 22.2%, tin 10.7%, cadmium 8.1%, zinc 1%), and the preparation method is the same as in example 1. Melting point temperature 47.18 ℃ by DSC test (see FIG. 3).

Comparative example 3

The liquid metal in this comparative example is (Bi)_40.7In_17.9Pb_22.4Sn_10.8Cd_8.2)₉₉+ 1% of Ga, system (mass percent, bismuth 40.3%, indium 17.7%, lead 22.2%, tin 10.7%, cadmium 8.1%, gallium 1%), the preparation method is a vacuum pumping method, comprising the following steps:

(1) polishing an alloy raw material for preparing liquid metal by using abrasive paper to remove oxide skin, putting the alloy raw material into a sample bag, adding absolute ethyl alcohol, and cleaning by using an ultrasonic cleaner;

(2) drying the cleaned alloy raw materials, weighing a sample with the total weight of 6g, and putting the sample into a long test tube (with the inner diameter of 9mm, the outer diameter of 12mm and the height of 29cm) according to the sequence of Cd, Bi, In, Pb, Sn and Ga;

(3) vacuumizing the small test tube with the sample by using a tube sealing machine, heating by using an alcohol lamp and continuously knocking the test tube until the sample is completely melted; the tube sealing machine needs 5-6 min for vacuum pumping until about-0.1-0 Pa is pumped.

(4) Taking out the test tube with the melted sample, rapidly sealing the test tube with sealing glue, placing the test tube in a temperature-controlled ultrasonic machine, setting the temperature at 80 ℃ for half an hour until the sample is completely melted uniformly, and finally preparing the liquid metal.

Melting point temperature was 41.90 ℃ by DSC test (see FIG. 2).

The liquid metal system and melting point in the above examples and comparative examples are shown in Table 1.

TABLE 1

	System of	TA-DSC melting Point (. degree. C.)
			Comparative example 1	Bi40.76In18.16Pb22.17Sn10.68Cd8.23	48.11
Comparative example 2	(Bi40.7In17.9Pb22.4Sn10.8Cd8.2)99+1％Zn	47.18
			Comparative example 3	(Bi40.7In17.9Pb22.4Sn10.8Cd8.2)99+ 1% Ga (vacuum method)	41.90
Example 1	(Bi40.7In17.9Pb22.4Sn10.8Cd8.2)99+ 1% Ga (tube sealing method)	40.15
			Example 2	(Bi40.7In17.9Pb22.4Sn10.8Cd8.2)98+2％Ga	40.18
Example 3	(Bi40.7In17.9Pb22.4Sn10.8Cd8.2)97+3％Ga	40.38
			Example 4	(Bi40.7In17.9Pb22.4Sn10.8Cd8.2)96+4％Ga	40.21
Example 5	(Bi40.7In17.9Pb22.4Sn10.8Cd8.2)95+5％Ga	40.56

As can be seen from Table 1, the melting point temperature of the six-component system provided by the invention has a tendency of being obviously reduced compared with the melting point of five-component liquid metal, and the melting point is obviously reduced compared with that of the BiInPbSnCd six-component metal added with Zn; the loss of each component in the reaction process can be ensured by adopting a tube sealing method, and the consistency of each component before and after the reaction is kept.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, many modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.