阅读说明：本技术 一种轴向电阻率梯度可控的合金板及制备方法 (Alloy plate with controllable axial resistivity gradient and preparation method thereof ) 是由 王艳林 钟华强 于 2021-08-25 设计创作，主要内容包括：本发明公开了一种轴向电阻率梯度可控的合金板,合金板是由若干个可导电的粉末块沿某一方向线性排列相接并高温烧结得到,各相邻的粉末块的电阻率不等、各粉末块各处的电阻率均相等,使合金板的电阻率沿线性排列方向梯度变化。通过调整各粉末块的电阻率、放置顺序即可改变合金板各段的电阻率、合金板轴向电阻率的变化趋势,实现对合金板轴向电阻率的控制,从而可以真实还原燃料元件或换热器的发热,模拟结果准确。且可以根据实际需要调整合金板各段的电阻率,调整方便。本发明还公开了合金板的制备方法,制备过程简单,不需要复杂的工艺、苛刻的条件,适用于工业化应用。(The invention discloses an alloy plate with controllable axial resistivity gradient, which is obtained by linearly arranging and connecting a plurality of conductive powder blocks along a certain direction and sintering at high temperature, wherein the resistivity of each adjacent powder block is unequal, and the resistivity of each powder block is equal, so that the resistivity of the alloy plate is changed in a gradient manner along the linear arrangement direction. The change trend of the resistivity of each section of the alloy plate and the axial resistivity of the alloy plate can be changed by adjusting the resistivity and the placing sequence of each powder block, and the control of the axial resistivity of the alloy plate is realized, so that the heating of a fuel element or a heat exchanger can be really reduced, and the simulation result is accurate. And the resistivity of each section of the alloy plate can be adjusted according to actual needs, and the adjustment is convenient. The invention also discloses a preparation method of the alloy plate, which has simple preparation process, does not need complex process and harsh conditions and is suitable for industrial application.)

1. The alloy plate with the controllable axial resistivity gradient is characterized in that the alloy plate is obtained by linearly arranging and connecting a plurality of conductive powder blocks along a certain direction and sintering at high temperature, the resistivity of each adjacent powder block is unequal, the resistivity of each powder block is equal, and the resistivity of the alloy plate is changed in a gradient manner along the linear arrangement direction.

2. An alloy plate having a controlled axial resistivity gradient according to claim 1, wherein each of the powder agglomerates is formed by mixing and pressing a plurality of conductive materials having different resistivity.

3. An alloy plate having a controlled axial resistivity gradient according to claim 1, wherein each of the powder agglomerates having different resistivity is formed by uniformly mixing and pressing metal powder and ceramic powder having different resistivity in different proportions.

4. An alloy plate having a controlled axial resistivity gradient according to claim 3, wherein the metal powder is 321 stainless steel powder and the ceramic powder is ZrO₂And (3) powder.

5. An alloy plate with a controlled axial resistivity gradient according to claim 1, wherein each of the powder pieces is a rectangular piece, and the thickness and volume of each of the powder pieces are equal, so that the powder pieces are linearly arranged and spliced to form a flat plate-like structure, and are sintered at high temperature to form a flat plate-like alloy plate.

6. The preparation method of the alloy plate with controllable axial resistivity gradient is characterized by comprising the following steps:

s1: uniformly mixing a plurality of powdery conductive materials with different resistivities according to a proportion, and pressing at normal temperature to form powder blocks;

s2: the powder blocks are arranged linearly and tightly along a certain direction and sintered at high temperature to obtain an alloy plate;

the powder lumps adjacent to each other have different resistivity.

7. The method of claim 6, wherein the powder agglomerates are formed by mixing and pressing metal powders having different electrical resistivity and ceramic powders.

8. The method of claim 6, wherein each powder slug is a rectangular slug, and the thickness and volume of each powder slug are equal, such that each powder slug is linearly arranged and spliced into a flat plate-like structure and sintered at high temperature into a flat plate-like alloy sheet.

Technical Field

The invention relates to the technical field of reactor thermal hydraulic power and engineering thermophysics, in particular to an alloy plate with controllable axial resistivity gradient and a preparation method thereof.

Background

In some research reactors or heat exchangers, plate-type fuel elements or plate-type heat exchangers are usually used, and heating or cooling characteristics of the plate-type fuel elements or the plate-type heat exchangers need to be simulated in the process of carrying out a thermal hydraulic experiment so as to facilitate the smooth carrying out of the thermal hydraulic experiment. When simulating the heating and cooling performance of a plate type fuel element or a plate type heat exchanger, a certain structure built by metal plates is generally adopted to simulate the heating of the fuel element or the heat exchanger.

For a metal plate of uniform thickness, the resistance is uniform along its length. However, in practice, the heating of the plate-type fuel element or the heat exchanger along the respective axial direction is not uniform, and the resistance of the metal plate in the length direction needs to be changed, so that the resistance of the metal plate in the length direction changes in a certain trend, and thus, the structure built by the metal plate can be accurately simulated when simulating the heating performance of the fuel element or the heat exchanger, and the structure can be closer to the actual heating performance of the fuel element or the heat exchanger and has more authenticity.

Disclosure of Invention

The invention aims to solve the technical problem that the result of the existing metal plate is inaccurate when the heating performance of a fuel element or a heat exchanger is simulated, and aims to provide an alloy plate with controllable axial resistivity gradient and a preparation method thereof, so that the problem that the simulation result is inaccurate because the heating condition of the existing metal plate in the axial direction of the fuel element or the heat exchanger is inconsistent due to the fact that the resistance of the existing metal plate in the length direction is the same, the heating of the fuel element or the heat exchanger cannot be really reduced is solved.

The invention is realized by the following technical scheme:

the first purpose of the invention is to provide an alloy plate with controllable axial resistivity gradient, wherein the alloy plate is obtained by linearly arranging and connecting a plurality of powder blocks along a direction and sintering at high temperature, the resistivity of each adjacent powder block is unequal, the resistivity of each powder block is equal, and the resistivity of the alloy plate is changed along the linear arrangement direction in a gradient manner.

Preferably, each of the powder pieces is formed by mixing and pressing a plurality of kinds of conductive materials having different electrical resistivity.

Preferably, each of the powder pieces is formed by mixing and pressing metal powder and ceramic powder having different electrical resistivity.

Preferably, the metal powder is 321 stainless steel powder, and the ceramic powder is ZrO₂And (3) powder.

Preferably, each powder block is a rectangular block, and the thickness and the volume of each powder block are equal, so that the powder blocks are linearly arranged and spliced to form a flat-plate-shaped structure and sintered at high temperature to form a flat-plate-shaped alloy plate.

The second purpose of the invention is to provide a preparation method of an alloy plate with controllable axial resistivity gradient, which comprises the following steps:

s1: uniformly mixing a plurality of powdery conductive materials with different resistivities according to a proportion, and pressing at normal temperature to form powder blocks;

s2: the powder blocks are arranged linearly and tightly along a certain direction and sintered at high temperature to obtain an alloy plate;

the powder lumps adjacent to each other have different resistivity.

Preferably, the powder block is formed by mixing and pressing metal powders having different electrical resistivity with ceramic powders.

Preferably, each powder block is a rectangular block, and the thickness and the volume of each powder block are equal, so that the powder blocks are linearly arranged and spliced to form a flat-plate-shaped structure and sintered at high temperature to form a flat-plate-shaped alloy plate.

Compared with the prior art, the invention has the following advantages and beneficial effects:

(1) according to the alloy plate with the controllable axial resistivity gradient, which is provided by the embodiment of the invention, a series of powder blocks with a conductive function are linearly arranged along one direction according to a certain sequence, a camera is arranged at a high temperature, the alloy plate is obtained, the resistivity of each adjacent powder block is unequal, the resistivity of each powder block is equal, and the resistivity of each powder block is changed in a gradient manner along the linear arrangement direction. The resistivity of each section of the alloy plate and the change trend of the resistivity of each section of the alloy plate can be changed by adjusting the resistivity of each powder block and the placement sequence of each powder block, so that the resistivity of the alloy plate in the axial direction can be controlled, and the alloy plate with a certain heating characteristic can be prepared according to actual needs. When the structure built by the alloy plate with controllable axial resistivity gradient provided by the embodiment of the invention is used for simulating the heating of the fuel element or the plate type heat exchanger, the heating of the fuel element or the heat exchanger can be really reduced, so that the simulation result is accurate. And the resistivity of each section of the alloy plate can be adjusted according to actual needs, and the adjustment is convenient.

(2) According to the alloy plate with the controllable axial resistivity gradient, provided by the embodiment of the invention, powder materials with different resistivities are selected and mixed according to a certain proportion to obtain powder blocks with certain resistivity, and then the powder blocks with certain resistivity are arranged according to design requirements, so that each section of the obtained alloy plate has specific resistivity, and the gradient change of the axial resistivity of the alloy plate is realized.

(3) According to the alloy plate with the controllable axial resistivity gradient, provided by the embodiment of the invention, each powder block is rectangular, and the thickness and the volume of each powder block are equal, so that a flat alloy plate is obtained. The shape and the size of each powder section are unified, the control of the resistivity of each section of the alloy plate is convenient, and in the preparation process of the alloy plate, the shape and the size of each powder section are unified, so that the preparation process is more convenient and efficient.

(4) The preparation method of the alloy plate with the controllable axial resistivity gradient, provided by the embodiment of the invention, has the advantages of simple preparation process, no need of complex process and harsh conditions, and suitability for industrial application.

Drawings

In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and that for those skilled in the art, other related drawings can be obtained from these drawings without inventive effort. In the drawings:

FIG. 1 is a schematic diagram of an arrangement structure of powder lumps in an alloy plate with controllable axial resistivity gradient according to an embodiment of the present invention;

fig. 2 is a graph of the variation trend of the resistivity of the alloy plate with controllable axial resistivity gradient along the length direction, provided by the embodiment of the invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not used as limitations of the present invention.

Throughout the specification, reference to "one embodiment," "an embodiment," "one example," or "an example" means: the particular features or characteristics described in connection with the embodiment or example are included in at least one embodiment of the present invention. Thus, the appearances of the phrases "one embodiment," "an embodiment," "one example" or "an example" in various places throughout this specification are not necessarily all referring to the same embodiment or example. Furthermore, the particular features, characteristics may be combined in any suitable combinations and/or sub-combinations in one or more embodiments or examples. Further, those of ordinary skill in the art will appreciate that the illustrations provided herein are for illustrative purposes and are not necessarily drawn to scale. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Example 1

As shown in the figure 1-2, the alloy plate with controllable axial resistivity gradient is obtained by linearly arranging and connecting a plurality of powder blocks along a certain direction and sintering at high temperature, the resistivity of each adjacent powder block is unequal, the resistivity of each powder block is equal, and the resistivity of the alloy plate is changed in a gradient way along the linear arrangement direction.

Specifically, according to the heating performance of a fuel assembly or a heat exchanger, the gradient change condition of the specific electrical resistivity of the required alloy plate is designed, then the powder blocks are linearly arranged together along a certain direction, the electrical resistivity of two adjacent powder blocks is unequal, and the electrical resistivity of each powder block at each position is equal. There may be equal resistivity for each powder slug, but powder slugs given equal resistivity are not placed adjacent to each other. The powder blocks are processed by certain conductive materials, the powder blocks are arranged as shown in figure 1 and then sintered at high temperature to form a whole alloy plate, the powder metallurgy process can be adopted for high-temperature sintering, and the specific temperature, pressure and sintering time in the high-temperature sintering process are determined according to the materials to be sintered. An alloy sheet having a resistivity varying in a gradient along the direction of linear alignment as shown in fig. 2 was obtained. Specifically, the powder metallurgy process is the prior art, the conditions and the used instruments and equipment in the process are all common in the powder metallurgy process, and the alloy plate can be obtained by adopting a conventional powder metallurgy method and high-temperature sintering, and the detailed description is omitted.

Specifically, the resistivity and the difference of the adjacent powder blocks can be adjusted by adjusting the conductive material forming the powder blocks. The powder lumps may be linearly arranged in the axial direction, that is, the longitudinal direction of the alloy sheet, in the sheet-like alloy sheet, or the arrangement order of the powder lumps may be set as necessary. The change trend of the resistivity of the alloy plate along the axial direction can be adjusted by changing the resistance of the powder block, the size of the powder block and the placement position of the powder block, so that the axial resistivity of the alloy plate can be controlled. In practical application, direct current can be adopted to heat the alloy plate, and gradient change of heat productivity can be realized along the length direction of the alloy plate, so that a fuel assembly and a heat exchanger are simulated really.

Example 2

This example is a modification made on the basis of example 1.

An alloy plate with controllable axial resistivity gradient is prepared from several electrically conducting materials with different resistivities through mixing, and die pressing at ordinary temp. Each powder block can be obtained by uniformly mixing two, three or more conductive materials with different resistivities, mixing and preparing according to a certain proportion and then pressing, and the type of the conductive material specifically forming the powder block can be selected according to actual needs, and preferably is formed by mixing and pressing two conductive materials with different resistivities. Powder blocks with different resistivity are obtained by different mixing ratios of the conductive materials.

More preferably, each powder block is formed by uniformly mixing metal powder and ceramic powder with different resistivity and then pressing. Most preferably, the metal powder is 321 stainless steel powder and the ceramic powder is ZrO₂And (3) powder. 321 stainless steel powder, ZrO₂The powders are all made of 321 stainless steel and ZrO by the known technology₂Pulverizing and grinding, which are not described herein. And 321 stainless steel powder, ZrO₂The particle size of the powder can be set as required as long as 321 stainless steel powder and ZrO are satisfied₂The powder can be uniformly mixed, and the resistivity of each powder block obtained by pressing is equal. By designing 321 stainless steel powder and ZrO₂Different mixing ratios of the powders result in a series of powder slugs with a certain resistivity.

The powder blocks can be arranged into rectangular blocks, the thickness and the volume of each powder block are equal, so that the length, the width and the height of each rectangular powder block are equal, the powder blocks are linearly arranged to be spliced into a flat structure, and then the flat alloy plate can be obtained through high-temperature sintering. As shown in FIG. 1, with the arrangement direction of each powder lump as the Z direction, the length direction of each powder lump as the Y direction, the height direction of the powder lumps as the X direction, and the coordinate axes set up, each powder lump was arranged along the Z-axis direction, 7 powder lumps were provided and defined as L1-L7, respectively, the resistivity of the powder lumps L1-L7 were different, and 321 stainless steel powder, ZrO powder in the powder lumps L1-L7 were different₂The mixing ratio of the powders was varied. The powder blocks L1-L7 are placed at corresponding positions as required to obtain a flat structure, and the resistivity of the alloy plate obtained by high-temperature sintering along the Z-axis direction is changed in a gradient manner, as shown in FIG. 2.

Specifically, the process of pressing powder materials with different resistivity at normal temperature to obtain powder blocks is the existing metal powder pressing technology, and the methods, reagents, instruments, molds and the like adopted in the process can all be adopted in the commonly used metal powder pressing technology, and are not detailed here.

Example 3

A preparation method of an alloy plate with controllable axial resistivity gradient comprises the following steps:

s1: uniformly mixing a plurality of powdery conductive materials with different resistivities according to a certain proportion, and then pressing at normal temperature to form a powder block;

s2: the powder blocks are linearly and closely arranged and connected along a certain direction, and then are sintered at high temperature to obtain an alloy plate;

the powder lumps adjacent to each other have different resistivity, and the powder lumps have equal resistivity.

The powder block is formed by mixing and pressing metal powder and ceramic powder with different resistivity. Each powder block is a rectangular block, the thickness and the volume of each powder block are equal, and the powder blocks are linearly arranged and spliced to form a flat-plate-shaped structure and sintered at high temperature to form a flat-plate-shaped alloy plate. And sintering the powder blocks into an alloy plate at high temperature by adopting a powder metallurgy process.

Parts not mentioned or detailed in this application are prior art or can be obtained or achieved by prior art.

The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.