Measuring apparatus, measuring method, and program

Abstract

To properly conduct characteristic evaluation of powder.SOLUTION: A measuring apparatus 100 comprises a storage part 61 serving as a holding part for holding information that indicates a relationship between impedance of powder P and a void fraction of the powder P. Further, the measuring apparatus 100 comprises: a die 30 provided with a housing hole 31a where the powder P is housed; a pair of electrode parts 40a, 40b sandwiching the powder P inserted to the housing hole 31a; a pressurizing part 50 for applying pressurizing force of heavy load for compacting the powder P to the pair of electrode parts 40a, 40b; and a measuring part 60 for measuring impedance of the powder P by supplying an electric signal of alternating current or direct current to the pair of electrode parts. In addition, the measuring apparatus 100 comprises a processing part 70 which refers to the information held in the storage part 60 to calculate a void fraction related to the measured impedance, when the measuring part 60 measures the impedance of the powder P.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a measurement device, a measurement method, and a program. [Background technology]

[0002] Patent Document 1 discloses a powder resistivity measuring device for measuring the volume resistivity of various powders. This measuring device gradually compresses the powder in a cylinder, measures the thickness of the powder in each compressed state with a height gauge, and measures the resistance value with a probe unit, thereby measuring the volume resistivity relative to the bulk density of the powder in each compressed state. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-179352 Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned powder measuring device measures the volume resistivity of the powder by measuring the volume of the powder, but does not measure the porosity of the powder. Furthermore, in order to properly evaluate the properties of the powder, it is desirable to measure the electrical properties while the molding pressure that is used to mold the powder for use in a product is acting on the powder.

[0005] The present invention has been made in consideration of the above problems, and has an object to provide a measuring device, a measuring method, and a program for appropriately measuring the porosity of various powders. [Means for solving the problem]

[0006] According to one aspect of the present invention, a measuring device for measuring powder includes a holding unit that holds information indicating the relationship between the impedance of a powder and the porosity of the powder, a die having a receiving hole for receiving the powder, a pair of electrodes that are inserted into the receiving hole to sandwich the powder, and a pressure unit that applies a high load pressure to the pair of electrodes to compress the powder. The measuring device further includes a measuring unit that measures the impedance of the powder by supplying an AC or DC electric signal to the pair of electrodes, and a processing unit that, when the measuring unit measures the impedance of the powder, refers to the information and calculates the porosity associated with the measured impedance. Equipped with.

[0007] According to one aspect of the present invention, a measurement method for measuring powder using a measurement device includes the steps of: retaining information indicating the relationship between the impedance of the powder and the porosity of the powder; accommodating the powder in an accommodating hole provided in a die for accommodating the powder; and compressing the powder by applying a high load pressure to a pair of electrodes sandwiching the powder. The measurement method further includes the steps of measuring the impedance of the powder by supplying an electric signal to the pair of electrodes; and, once the impedance of the powder has been measured, calculating the porosity associated with the measured impedance by referring to the information. [Effects of the Invention]

[0008] In these embodiments, the porosity of the powder can be obtained by measuring the impedance while compressing the powder. Furthermore, because a high load pressure is applied to the powder, the electrical characteristics can be measured in a state that matches the actual product state, even for powders that are molded under high pressure as a product. Therefore, the porosity of various powders can be measured appropriately. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view showing a measuring device according to an embodiment of the present invention. [Figure 2]FIG. 2 is a block diagram showing the measurement device of this embodiment. [Figure 3] FIG. 3 is an enlarged view showing the periphery of the die of the measuring device of this embodiment. [Figure 4] FIG. 4 is a partially enlarged view of the measurement device for explaining the correction step in the measurement method of this embodiment. [Figure 5] FIG. 5 is a diagram for explaining the correction process in the measurement method of this embodiment, and is a graph showing the load on the slider on the horizontal axis and the displacement of the slider on the vertical axis. [Figure 6] FIG. 6 is a partially enlarged view of the measuring device for explaining the accommodation step in the measuring method of this embodiment. [Figure 7] FIG. 7 is a diagram for explaining the trigger step in the measurement method of this embodiment, and is a graph showing time on the horizontal axis and slider displacement on the vertical axis. [Figure 8] FIG. 8 is a diagram for explaining the calculation process in the measurement method of this embodiment, and is a graph showing the porosity of the powder P on the horizontal axis and the impedance of the powder P on the vertical axis. [Figure 9] FIG. 9 is a flowchart showing the measurement method of this embodiment. [Figure 10] FIG. 10 is a flowchart showing a method for generating information indicating the relationship between impedance and porosity in this embodiment. [Figure 11] FIG. 11 is a diagram for explaining the production method of this embodiment, and is a graph showing the porosity of the powder P on the horizontal axis and the impedance of the powder P on the vertical axis. [Figure 12] FIG. 12 is an enlarged cross-sectional view showing a modification of the measuring device of this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] A measurement device 100 and a measurement method according to an embodiment of the present invention will be described below with reference to the drawings.

[0011] First, the overall configuration of a measuring device 100 according to an embodiment will be described with reference to Fig. 1 to Fig. 3. Fig. 1 is a cross-sectional view showing the measuring device 100 according to an embodiment. Fig. 2 is a block diagram showing the measuring device 100. Fig. 3 is an enlarged view showing the periphery of a die 30 of the measuring device 100 (part A in Fig. 1).

[0012] The measuring device 100 measures the electrical characteristics of powder P (see FIG. 3 etc.) which is the object to be measured. In this embodiment, an example will be described in which the powder P which is the object to be measured is a solid electrolyte used in an all-solid-state battery. The measuring device 100 applies a high pressure load to the powder P to compress the powder P, and measures the impedance of the powder P. Note that the powder P which is the object to be measured is not limited to a solid electrolyte for an all-solid-state battery, and may be any other powder.

[0013] As shown in Figures 1 and 2, the measuring device 100 includes a press device 10 that has a pair of electrode units 40a, 40b that apply an electric signal to the powder P and pressurizes the powder P, a measuring unit 60 that measures the electrical characteristics based on the electric signal applied to the powder P, and a processing unit 70 that processes the measurement results of the measuring unit 60.

[0014] The press device 10 includes a frame 2 mounted on a stand 1 placed on the ground, a slider 20 attached to the frame 2 so as to be movable in the vertical direction, a die 30 provided with a storage hole 31a for storing powder P, a pair of electrode sections 40a, 40b inserted into the storage hole 31a on which the die 30 is placed and which moves vertically to sandwich the powder P, and a pressure section 50 that applies a high load pressure to the pair of electrode sections 40a, 40b to compress the powder P.

[0015] The frame 2 has a pair of tables 3a, 3b spaced apart in the vertical direction, a plurality of posts (not shown) connecting the pair of tables 3a, 3b, and a pair of guide rods 4 that guide the movement of the slider 20 along the vertical direction. The pair of tables 3a, 3b are connected to each other so as not to move relative to each other by, for example, four posts that are provided on all four sides of the slider 20 and extend in the vertical direction. The pair of guide rods 4 each extend in the vertical direction, and both ends are connected to the pair of tables 3a, 3b.

[0016] A pair of sleeves 21, through which the pair of guide rods 4 are inserted, are attached to the slider 20, and the slider 20 slides on the guide rods 4 via the sleeves 21. The slider 20 moves vertically along the guide rods 4 between the pair of tables 3a, 3b.

[0017] As shown in FIG. 3, the die 30 has an inner die 31 in which the receiving hole 31 a is formed, and an outer die 35 provided outside the inner die 31 .

[0018] The inner die 31 is formed in an annular shape, and has a receiving hole 31a, which is a circular through-hole, at its center. The inner die 31 is made of an insulating material. In this embodiment, the inner die 31 is made of a ceramic material that has insulating properties and can withstand high load pressure (pressing pressure).

[0019] The outer die 35 is formed in an annular shape and has a die receiving hole 35a, which is a circular through-hole, at its center. The inner die 31 is attached to the outer die 35 while being inserted into the die receiving hole 35a. By providing the outer die 35 outside the inner die 31, durability against press pressure can be reinforced. The outer die 35 is desirably formed from a highly durable material, such as metal, regardless of whether it has insulating properties.

[0020] The die 30 is not limited to a configuration including the inner die 31 and the outer die 35, but may be made up of one member or three or more members.

[0021] In this embodiment, the pair of electrode portions 40a, 40b are formed to have the same shape. One electrode portion 40a is fixed to the upper table 3a by an attachment portion 45a. The other electrode portion 40b is fixed to the slider 20 by an attachment portion 45b. As the slider 20 moves in the vertical direction, the electrode portion 40b attached to the slider 20 moves forward and backward in the vertical direction relative to the other electrode portion 40a. In this way, the pair of electrode portions 40a, 40b are configured to move relative to each other in the vertical direction.

[0022] Each electrode portion 40a, 40b has a plate-like flange portion 41a, 41b having a cross-sectional area larger than the cross-sectional area of ​​the accommodation hole 31a of the die 30, and a cylindrical boss portion 42a, 42b protruding axially from one end face of the flange portion 41a, 41b and inserted into the accommodation hole 31a. The boss portions 42a, 42b are provided coaxially with the corresponding flange portions 41a, 41b and formed with an outer diameter slightly smaller than the inner diameter of the accommodation hole 31a of the die 30. Therefore, the cross section of the electrode portions 40a, 40b along the central axis is formed to be approximately T-shaped. The die 30 is placed on the lower electrode portion 40b with the boss portion 42b of the lower electrode portion 40b, which is fixed to the slider 20, inserted into the accommodation hole 31a of the inner die 31.

[0023] Gas contained in the powder P compressed by the pair of electrodes 40a, 40b is discharged to the outside of the accommodation hole 31a through a gap between the inner periphery of the accommodation hole 31a and the outer periphery of the boss portions 42a, 42b of the die 30. The electrode portions 40a, 40b have flange portions 41a, 41b with a larger cross-sectional area than the boss portions 42a, 42b inserted into the accommodation hole 31a, and this increases the pressure-receiving area for the pressing force, which is the contact area with the tables 3a, 3b, and ensures durability.

[0024] Each of the electrode units 40a, 40b is formed of a conductive material (e.g., metal). As shown in FIG. 1, one of the electrode units 40a is connected to an application wire 71a (source wire) that guides an electrical signal from the measurement unit 60 and a measurement wire 72a (sense wire) that guides a response signal obtained by applying an electrical signal to the powder P. Similarly, the other electrode unit 40b is connected to an application wire 71b and a measurement wire 72b. The application wires 71a, 71b and the measurement wires 72a, 72b are connected to the electrode units 40a, 40b via connectors (not shown) attached to the outer circumferential surfaces (cylindrical surfaces) of the flange units 41a, 41b, respectively. The measurement unit 60 performs AC impedance measurement by four-terminal measurement in which signals are communicated via a pair of application wires 71a, 71b and measurement wires 72a, 72b. Furthermore, since each electrical wiring (71a, 71b, 72a, 72b) is connected to the outer peripheral surfaces of the flange portions 41a, 41b, rather than to the end surfaces of the flange portions 41a, 41b of the electrode portions 40a, 40b that receive the pressure force, the electrode portions 40a, 40b and each electrical wiring (71a, 71b, 72a, 72b) can be stably connected without being affected by the pressure force.

[0025] Furthermore, the pair of electrode parts 40a, 40b receives pressure from the pressure unit 50 and compresses the powder P placed between them in the containing hole 31a. That is, the pair of electrode parts 40a, 40b not only function as electrodes that communicate electrical signals with the measurement unit 60, but also function as dies that compress the powder P.

[0026] The mounting portion 45a provided on the upper table 3a has a plate-shaped base portion 46a provided between the upper table 3a and the flange portion 41a of the electrode portion 40a, and a holder portion 47a that engages with the flange portion 41a of the electrode portion 40a and is attached to the upper table 3a. The base portion 46a is formed with an outer diameter larger than that of the flange portion 41a of the electrode portion 40a. The base portion 46a and holder portion 47a of the mounting portion 45a are each formed from an insulator.

[0027] Similar to the mounting portion 45a of the upper table 3a, the mounting portion 45b provided on the slider 20 has a plate-shaped base portion 46b provided between the slider 20 and the flange portion 41b of the electrode portion 40b, and a holder portion 47b that is attached to the slider 20 by engaging with the flange portion 41b of the electrode portion 40b. The base portion 46b is formed to have a larger outer diameter than the flange portion 41b of the electrode portion 40b. The base portion 46b and holder portion 47b of the mounting portion 45b of the slider 20 are each formed from an insulator.

[0028] The pair of electrodes 40a, 40b are attached to the upper table 3a or the slider 20 via attachment portions 45a, 45b made of an insulator, thereby insulating the pair of electrodes 40a, 40b from the upper table 3a and the slider 20. The attachment portions 45a, 45b may be made of any insulating material. In this embodiment, the insulator used for the attachment portions 45a, 45b is a ceramic material, similar to the inner die 31.

[0029] The pressure unit 50 is a pressure source that applies pressure to the pair of electrode units 40a, 40b, and in this embodiment is an electric hydraulic jack provided between the lower table 3b and the slider 20. When hydraulic pressure is supplied to the pressure unit 50, it extends and applies a vertically upward pressure to the slider 20. The slider 20 receives the pressure from the pressure unit 50 and moves vertically upward together with the die 30 and electrode unit 40b on the slider 20. Pressure acts on the powder P between the electrode unit 40b attached to the slider 20 and the electrode unit 40a attached to the upper table 3a, compressing the powder P. When the pressure is released, the pressure unit 50 contracts due to the weight of the slider 20.

[0030] The pressure applying unit 50 is not limited to a hydraulic jack, but may be a mechanical (screw type) or pneumatic jack. The pressure applying unit 50 is also not limited to a jack, but may have any configuration as long as it is capable of exerting a pressure force. In other words, the press device 10 is not limited to a hydraulic type, but may be another type of hydraulic pressure, or may be a mechanical or electric type.

[0031] The hydraulic jack constituting the pressurizing unit 50 is selected so as to apply a desired pressure to the powder P. In this embodiment, since the measurement target is the powder P, which is a material for the solid electrolyte of an all-solid-state battery, a hydraulic jack is selected that can apply a high-load pressure close to the molding pressure of the solid electrolyte to the powder P in the accommodating hole 31a relative to the area (pressure-receiving area) of the tips of the boss portions 42a, 42b of the pair of electrode portions 40a, 40b that contact the powder P. Specifically, the pressurizing unit 50 is configured to be able to exert a high-load pressure that applies a pressure of 750 MPa or more to the powder P in the accommodating hole 31a.

[0032] The measuring unit 60 is an LCR meter that measures inductance, capacitance, resistance, impedance, etc. Note that the measuring unit 60 is not limited to an LCR meter, and may be, for example, a vector network analyzer (VNA).

[0033] More specifically, the measurement unit 60 supplies AC or DC electrical signals to the pair of electrodes 40a, 40b via the application wirings 71a, 71b, and measures the AC or DC impedance based on response signals transmitted from the pair of electrodes 40a, 40b via the measurement wirings 72a, 72b. In this embodiment, the measurement unit 60 applies an AC voltage to the pair of electrodes 40a, 40b, and measures a complex AC impedance based on the response current transmitted via the measurement wirings 72a, 72b.

[0034] The processing unit 70 is a computer equipped with an arithmetic processing unit such as a CPU, a storage device, a display device, an input device, a network connection device, etc. The processing unit 70 in Fig. 2 includes a storage unit 61 configured as a storage device and a display unit 62 configured as a display device.

[0035] The storage unit 61 is configured, for example, with RAM (Random Access Memory) and ROM (Read Only Memory), and functions as a storage unit that stores measurement results, information, etc. The storage unit 61 also stores a program for controlling the operation of the measuring device 100. In other words, the storage unit 61 is a computer-readable recording medium that stores the program of this embodiment.

[0036] The processing unit 70 is electrically connected to the measurement unit 60, and controls the operation of the measurement unit 60 to obtain the measurement results from the measurement unit 60. The processing unit 70 also controls the operation of the pressurizing unit 50. The processing unit 70 performs various processes described in this specification by having the CPU execute programs stored in advance in the storage device.

[0037] Although the processing unit 70 is configured by one computer, it is not limited to this and may be configured by a plurality of microcomputers, with each control being distributed among the plurality of computers.

[0038] The press device 10 has a displacement sensor 55 as a displacement measuring unit that measures the relative displacement of the pair of electrode units 40a, 40b, and a load sensor 57 as a load measuring unit that measures the load applied to the powder P.

[0039] The displacement sensor 55 is a contact-type displacement sensor attached to the lower table 3b via a bracket 56, with the tip of a contactor 55a coming into contact with the underside of the slider 20. The displacement sensor 55 measures the displacement of the slider 20, and therefore the relative displacement in the vertical direction between the pair of electrode portions 40a, 40b. The displacement sensor 55 may be of another measurement type, such as an optical type. The measurement results of the displacement sensor 55 are input to the processing unit 70.

[0040] The load sensor 57 is, for example, a load cell, and is provided between the pressure unit 50 and the slider 20. The load sensor 57 measures the pressure (load) applied from the pressure unit 50 to the slider 20. The measurement result of the load sensor 57 is input to the processing unit 70. The measurement results of the displacement sensor 55 and the load sensor 57 are stored in the processing unit 70 in association with each other.

[0041] Next, the measurement method of this embodiment will be described with reference to Figs. 4 to 9. Fig. 4 is a partially enlarged view of measurement device 100 for explaining the correction step in the measurement method. Fig. 5 is a diagram for explaining the correction step in the measurement method, and is a graph showing the load on slider 20 on the horizontal axis and the displacement of slider 20 on the vertical axis. Fig. 6 is a partially enlarged view of measurement device 100 for explaining the accommodation step in the measurement method. Fig. 7 is a diagram for explaining the trigger step in the measurement method, and is a graph showing time on the horizontal axis and the displacement of slider 20 on the vertical axis.

[0042] 6, the measurement method of this embodiment acquires the porosity of the powder P from porosity information indicating the correspondence relationship between the impedance and porosity of the powder P and the measured impedance of the powder P. The porosity here means the ratio of the volume occupied by voids to the total volume of the powder P.

[0043] Before executing the measurement method of this embodiment, a generation method for generating the above-mentioned porosity information is executed. Specifically, the generation method of this embodiment includes the steps of correcting the measurement result of the displacement sensor 55 (correction step), storing the powder P in the storage hole 31a provided in the die 30 in which the powder P is stored (storage step), compressing the powder P by applying a high load pressure to the pair of electrodes 40a, 40b that sandwich the powder P (compression step), measuring the impedance of the powder P by applying an AC signal to the pair of electrodes 40a, 40b (impedance measurement step), and acquiring the porosity of the powder P from the volume of the powder P acquired based on the relative displacement of the pair of electrodes 40a, 40b measured by the displacement measurement unit and the measured impedance.

[0044] First, the correction step that is performed before the step of acquiring the porosity of the powder P will be described.

[0045] [Correction process] In the production method of this embodiment, the porosity of the powder P is obtained as will be described later with reference to Fig. 10. For this purpose, the displacement of the slider 20 is measured by the displacement sensor 55, and the volume of the compressed powder P is obtained from the displacement of the slider 20.

[0046] In the press device 10, when pressure is applied to the pair of electrode portions 40a, 40b, the powder P in the storage hole 31a of the die 30 is sandwiched between the pair of electrode portions 40a, 40b and compressed, and gas contained in the powder P is discharged to the outside of the die 30. In the process of compressing the powder P in this way, the volume of the powder P is reduced by the gas being discharged, and the pressure force of the pressure portion 50 also causes deformation (basically elastic deformation) in each component of the press device 10.

[0047] For this reason, the displacement of the slider 20 measured by the displacement sensor 55 includes not only the compression of the powder P but also the displacement due to the deformation of the press device 10. If the volume of the powder P is obtained from the measurement results of the displacement sensor 55 that also include the displacement due to the deformation of the press device 10, the error from the actual volume will be large, and it will be impossible to obtain the porosity of the powder P with high accuracy.

[0048] Therefore, in the correction process of this embodiment, the reference point (zero point) of the displacement sensor 55 is adjusted, and the amount of deformation of the press device 10 due to the application of pressure is obtained. During the correction process, the displacement of the slider 20 is measured by the displacement sensor 55, and the pressure applied to the slider 20 is measured by the load sensor 57.

[0049] In the correction process, first, as shown in FIG. 4, with the housing hole 31a of the die 30 empty and without powder P contained therein, the slider 20 is moved upward to insert the boss 42a of the upper electrode 40a into the housing hole 31a, and the tips of the bosses 42a and 42b of the electrodes 40a and 40b are brought into direct contact with each other. Then, with the tips of the bosses 42a and 42b in contact, a predetermined first load F1 (e.g., 1 kN) greater than zero is applied to the electrodes 40a and 40b based on the measurement result of the load sensor 57. The value of the displacement sensor 55 (first measurement result) when the first load F1 is applied is set as a reference point (zero point). Next, a second load F2 (e.g., the upper limit of the pressure force that the pressure unit 50 can exert) greater than the first load F1 is applied to the electrodes 40a and 40b, and the value of the displacement sensor 55 (second measurement result) at this time is obtained. The value of the displacement sensor 55 when the second load F2 is applied indicates the amount of deformation of the press device 10.

[0050] Next, the relationship between the value of the displacement sensor 55 and the load (the value of the load sensor 57) is obtained from the first measurement result (zero), which is the value of the displacement sensor 55 when the first load F1 is applied, and the second measurement result, which is the value of the displacement sensor 55 when the second load F2 is applied. In this embodiment, two types of loads, the first load F1 and the second load F2, are applied to the electrodes 40a and 40b. Therefore, as shown in FIG. 5, the displacement of the slider 20 and the loads applied to the electrodes 40a and 40b are assumed to have a linear relationship, and the relationship between the displacement of the slider 20 and the load is obtained as a linear equation with a slope a (=u2 / (F2-F1)). Note that the magnitude of the applied load may be set to three or more, and the relationship between the displacement of the slider 20 and the load may be obtained as a nonlinear equation from the obtained results of the displacement sensor 55. The relationship between the displacement of the slider 20 and the load obtained in this manner is stored in the processing unit 70.

[0051] By understanding the relationship between the displacement of the slider 20 and the load in advance, it is possible to understand the amount of deformation of the press device 10 when the powder P is compressed with a predetermined load. Therefore, if the measurement result of the load sensor 57 is F and the measurement result of the displacement sensor 55 is u, the thickness t of the powder P can be calculated using the following equation (1). In the subsequent steps, the thickness of the powder P obtained by correcting the measurement result of the displacement sensor 55 in this way is used.

[0052] (Number 1) t=ua(F-F1)=u-u2·(F-F1) / (F2-F1)···(1)

[0053] It should be noted that such a correction step needs to be performed only once before measuring the electrical characteristics of the powder P, and does not need to be performed every time the electrical characteristics of the powder P are measured. Furthermore, if the deformation of the press device 10 due to the pressure applied to the powder P is negligible in evaluating the characteristics of the powder P, the step of acquiring the amount of deformation of the press device 10 and correcting the measurement results of the displacement sensor 55 is not essential.

[0054] In addition, in the correction process, in addition to the configuration of the displacement sensor 55, the processing unit 70 may perform processes such as open / short correction to correct the wiring resistance between the processing unit 70 and the electrode units 40a, 40b and the contact resistance between the electrode units 40a, 40b and the powder P.

[0055] Next, a method for actually measuring the porosity of the powder P will be described.

[0056] [Storage process] In a preparation state before measuring the porosity of the powder P, the pressurizing unit 50 does not exert a pressure and re-shrinks due to the weight of the slider 20. In the preparation state, the die 30 on the slider 20 is retracted from the upper electrode portions 40a, 40b, and the boss portions 42a, 42b of the upper electrode portions 40a, 40b are not inserted into the accommodation hole 31a of the die 30 and are separated therefrom.

[0057] 6, in the accommodation step, powder P is introduced into the accommodation hole 31a of the die 30 of the press apparatus 10 in the prepared state. The mass of the introduced powder P is measured in advance and stored in the processing unit 70. Note that in the accommodation step, the die 30 and the pair of electrodes 40a, 40b may be removed from the press apparatus 10 (table 3a, slider 20), and the powder P may be introduced into the accommodation hole 31a with the boss portion 42b of the lower electrode portion 40b inserted into the accommodation hole 31a of the die 30. Next, the boss portion 42a of the upper electrode portion 40a may be inserted into the accommodation hole 31a. Thereafter, the die 30 and the pair of electrodes 40a, 40b may be attached to the press apparatus 10 with the powder P introduced.

[0058] [Compression process] The powder P is introduced into the receiving hole 31a of the die 30 in the receiving step, and the compression step is started when, for example, an operator operates a measurement start button (not shown). Furthermore, when the compression step is started, measurements by the displacement sensor 55 and the load sensor 57 are started.

[0059] In the compression step, the operation of the pressure unit 50 is controlled by a control signal from the processing unit 70, and the pressure unit 50 applies a pressure force to the slider 20. This causes the slider 20 to move vertically upward. As the slider 20 moves upward, the bosses 42a, 42b of the upper electrode portions 40a, 40b are inserted into the receiving hole 31a of the die 30 and eventually come into contact with the powder P inside the receiving hole 31a. As the slider 20 is further pressurized upward from this state, the powder P sandwiched between the pair of electrode portions 40a, 40b is subjected to the pressure force and compressed (see FIG. 3).

[0060] When a stop signal is sent from the processing unit 70 to the pressure unit 50, the pressure exerted by the pressure unit 50 decreases, and the pressure unit 50 contracts due to the weight of the slider 20. When the pressure unit 50 contracts to its fullest extent and the press device 10 returns to the ready state, the compression process is completed.

[0061] During this compression step, the processing unit 70 performs a measurement trigger step of issuing a trigger to start an impedance measurement step, which will be described later.

[0062] The measurement trigger process will now be described.

[0063] Powder P usually contains gas, so in the early stages of compressing powder P, the volume of powder P changes significantly, and because it contains gas, it is not suitable for measuring the electrical properties of powder P. When the gas contained in powder P is released, the change in thickness of powder P becomes smaller, as shown in Figure 7. In the measurement trigger process, this decrease in the change in thickness of powder P (point T in the figure) is detected, and a trigger for impedance measurement is issued.

[0064] More specifically, as described above, the measurement results of the displacement sensor 55 and the load sensor 57 are input to and stored in the processing unit 70 at predetermined time intervals (sampling intervals). When the measurement result of the displacement sensor 55 is input to the processing unit 70, the processing unit 70 calculates the amount of change in displacement of the slider 20 per unit time (hereinafter simply referred to as the "amount of change in displacement") based on the measurement result of the displacement sensor 55.

[0065] When the amount of displacement change of the slider 20 is calculated, the processing unit 70 compares the amount of displacement change with a threshold value stored in advance in the processing unit 70. Then, when the amount of displacement change of the slider 20 falls below the threshold value, a command signal to execute the impedance measurement process is sent to the measuring unit 60. In this way, a trigger to start the impedance measurement is issued.

[0066] [Impedance measurement process] In the impedance measurement step, which is performed by being triggered by the processing unit 70, an AC or DC electric signal is supplied to the powder P, and the impedance of the powder P is measured as an electrical characteristic.

[0067] In this embodiment, the measurement unit 60 applies an AC voltage of a specific frequency to the pair of electrodes 40a, 40b, and detects the value of the current flowing between the electrodes 40a, 40b to measure the impedance of the powder P. The frequency of the AC voltage is set to any value within a range of, for example, 4 Hz to 8 MHz.

[0068] Alternatively, the measuring unit 60 may measure the impedance of the powder P by applying a DC voltage instead of an AC voltage to the powder P. Alternatively, the measuring unit 60 may apply a predetermined AC voltage as an AC signal to the pair of electrodes 40a, 40b while sweeping the frequency within a predetermined frequency range, and detect the value of the current flowing between the electrodes 40a, 40b to measure the impedance of the powder P at each frequency. The frequency range over which the frequency is swept is set depending on the object to be measured, and in this embodiment, it is set to, for example, 4 [Hz] to 8 [MHz].

[0069] The results of the impedance measurement are stored in the storage unit 61 that constitutes the processing unit 70. In this embodiment, the results are stored in the storage unit 61 in association with the frequency of the AC voltage and the displacement of the slider 20. When the impedance measurement is completed, a control signal indicating the end of the impedance measurement process is transmitted from the measurement unit 60 to the processing unit 70. In response to this control signal, the processing unit 70 stops the application of pressure by the pressure unit 50 and ends the compression process. In other words, the impedance measurement process is performed in parallel with the compression process.

[0070] The impedance measurement process is triggered when the displacement change of the slider 20 falls below a set value and the volume change of the powder P is detected to be small. Therefore, measurement can be started promptly once the gas is discharged from the powder P and the powder P reaches a stable state. Even if impedance measurement is performed when the powder P contains gas, the impedance of the powder P itself cannot be accurately measured due to the gas contained in the powder P. Furthermore, if measurement is not performed even after the gas has been discharged from the powder P and stabilized, time will be wasted and work efficiency will decrease. By triggering the impedance measurement process at the appropriate time using the measurement trigger process, the impedance of the powder P can be measured accurately and efficiently. Furthermore, because the impedance measurement process is automatically triggered based on the measurement results of the displacement sensor 55, reproducibility of repeated measurements can be improved.

[0071] The impedance measuring step may be performed by supplying AC or DC current as an electrical signal to the pair of electrode portions 40a and 40b.

[0072] [Calculation process] In the calculation step, the void ratio of the powder P in the receiving hole 31a of the die 30 is calculated by the processing unit .

[0073] The porosity of the powder P is calculated from the porosity information stored in advance in the storage unit 61 and the impedance measured in the impedance measurement step.

[0074] Furthermore, the impedance of the powder P used in the calculation is measured using either or both of the real and imaginary parts of the impedance. Alternatively, when impedance measurement is performed using a frequency sweep, the measured value of the DC resistance obtained by equivalent circuit analysis may be used as the impedance of the powder P.

[0075] The porosity information indicates the relationship between the impedance of a predetermined powder that is the same or the same type as the powder P and the porosity of the predetermined powder. As the porosity information, for example, a table indicating the porosity of a predetermined powder for each impedance value of the predetermined powder, or a relational expression indicating the relationship between the impedance and porosity of a predetermined powder, is used.

[0076] In this way, when the impedance of the powder P is measured by the measuring unit 60, the processing unit 70 refers to the porosity information stored in the memory unit 61 and calculates the porosity associated with the measured impedance value. This makes it possible to obtain the porosity of the powder P. Using the obtained porosity, it is possible to evaluate the characteristics of the powder P.

[0077] Fig. 8 is a diagram showing an example of acquiring the porosity of the powder P in this embodiment. Fig. 8 illustrates, as porosity information, the porosity of the powder P for each impedance value of the powder P at a specific frequency. In this example, the vertical axis represents the value of the real part of the impedance, and the horizontal axis represents the porosity of the powder.

[0078] When the processing unit 70 acquires the measured value R1 of the real part of the impedance of the powder P measured in the measurement step, the processing unit 70 calculates a porosity P1 associated with the measured value R1 by referring to the porosity information stored in the storage unit 61. Then, the processing unit 70 acquires the calculated value of the porosity P1 as the porosity of the powder P.

[0079] Next, a method for measuring the porosity of the powder P in a state compressed at a predetermined pressure will be described with reference to FIG.

[0080] FIG. 9 is a flowchart showing an example of the processing procedure of the measurement method performed by the measurement device 100.

[0081] In step S1, the measuring device 100 holds information indicating the relationship between the impedance of a predetermined powder that is the same as or of the same type as the powder P and the porosity of the predetermined powder.

[0082] In step S2, the measuring device 100 accommodates the powder P in the accommodation hole 31a provided in the die 30 for accommodating the powder P. Step S2 corresponds to the accommodation step described above.

[0083] In step S3, the measuring device 100 applies a high load pressure to the pair of electrode units 40a, 40b that sandwich the powder P, thereby compressing the powder P. In this embodiment, the pressure unit 50 of the measuring device 100 applies a pressure of 750 MPa or more to the powder P. Step S3 corresponds to the compression step described above.

[0084] In step S4, the measuring device 100 supplies an electric signal to the pair of electrode parts 40a, 40b to measure the impedance of the powder P. Step S4 corresponds to the impedance measuring step described above.

[0085] In step S5, when the impedance of the powder P is measured, the measuring device 100 refers to the porosity information and calculates the porosity associated with the measured impedance of the powder P. Step S5 corresponds to the above-mentioned calculation step.

[0086] As described above, the measuring device 100 that executes the measuring method of this embodiment measures AC impedance while compressing the powder P under a high load. Therefore, it is useful for measuring the porosity of the powder P, which takes into account the capacitance component in characteristic evaluation. The porosity of the powder P is an effective index because it can be used, for example, as a guide when injecting an electrolyte solution in the process of impregnating the electrolyte solution into the electrodes of a battery.

[0087] Furthermore, in this embodiment, since the powder P is compressed under a high load, the contact resistance between the electrode portions 40a, 40b and the powder P can be reduced, and the measurement accuracy of the impedance of the powder P itself can be improved. Furthermore, for powder P used in products with high molding pressure, the electrical characteristics can be measured while applying a pressure equivalent to the actual molding pressure, and characteristic evaluation can be performed that is more in line with the product state.

[0088] The characteristics of the solid electrolyte of an all-solid-state battery are evaluated by AC impedance measurement, and the powder P is molded under a relatively high load pressure. Therefore, the measuring device 100 and the measuring method of this embodiment are particularly useful for measuring the electrical characteristics of the solid electrolyte of an all-solid-state battery.

[0089] In the measurement method of this embodiment, the measurement trigger step may be performed before the processing of step S4 is executed.

[0090] Next, a method for generating the porosity information stored in the storage unit 61 will be described with reference to Fig. 11. This generation method corresponds to a pre-processing step of the calculation step in this embodiment.

[0091] 10 is a flowchart showing an example of the processing procedure of the generation method in this embodiment. Steps S12 to S14 correspond to steps S2 to S4 in FIG.

[0092] In step S11, the processing unit 70 acquires the true density and mass of the powder P from the memory unit 61. The true density of the powder P can be a value measured by a true density meter, a literature value, a theoretical value, or the like, and the mass of the powder P is a value measured in advance. These values ​​are input, for example, by an input device of the processing unit 70 and stored in advance in the memory unit 61 of the processing unit 70.

[0093] In step S12, the measuring device 100 accommodates the powder P in the accommodation hole 31a provided in the die 30 in which the powder P is accommodated.

[0094] In step S13, the measuring device 100 starts compressing the powder P by the pressure unit 50 in order to apply a high pressure load to the pair of electrode units 40a, 40b sandwiching the powder P to compress the powder P. As a result, the pressure applied to the pair of electrode units 40a, 40b is gradually increased, and the powder P is gradually compressed.

[0095] In step S14, the measuring device 100 supplies an electric signal to the pair of electrode units 40a, 40b to measure the impedance of the powder P. In this embodiment, the measuring unit 60 measures the value of the real part of the impedance of the powder P.

[0096] In step S15, the measuring device 100 measures the volume of the powder P from the displacement of the slider 20 (thickness of the powder P) calculated from the measurement result of the displacement sensor 55 and the inner diameter of the containing hole 31a. Note that in step S15, the volume of the powder P may be corrected using the result of the above correction process.

[0097] In this way, the processing unit 70 acquires the impedance of the powder P and the volume of the powder P in a pressure increasing state in which the pressure applied to the pair of electrode units 40a, 40b is gradually increased.

[0098] In step S16, the processing unit 70 calculates the porosity of the powder P from the true density and mass of the powder P acquired in step S11 and the volume of the powder P measured in step S15.

[0099] Specifically, the processing unit 70 calculates the volume v at true density from the true density and mass of the powder P, subtracts the value obtained by dividing the volume v at true density of the powder P by the volume V of the powder P based on the measurement results of the displacement sensor 55 from 1, and multiplies the subtracted value by 100 to calculate the porosity ε of the powder P, as shown in the following equation (2).

[0100] (Number 2) ε = (1 - v / V) × 100 (2)

[0101] Then, the processing unit 70 records the calculated porosity of the powder P and the real part of the impedance of the powder P measured in step S14 in the storage unit 61 in association with each other.

[0102] In step S17, the processing unit 70 determines whether the pressure applied to the powder P is less than a predetermined value. The pressure applied to the powder P is calculated from the measurement result of the load sensor 57 and the tip diameter (area) of the cylindrical boss portions 42a, 42b inserted into the receiving hole 31a of the die 30. The predetermined value is set to, for example, the upper limit of the pressure that can be applied to the powder P by the pressurizing unit 50, or the allowable pressure value of the powder P.

[0103] It should be noted that the upper limit pressure may be limited using the detection value of the load sensor 57 instead of the pressure value of the pressure applied to the powder P.

[0104] Thereafter, if it is determined in step S17 that the pressure on the powder P is less than a predetermined value, the processing unit 70 returns to step S14, acquires measured values ​​of the impedance and volume of the powder P, and calculates the porosity of the powder P.

[0105] On the other hand, if it is determined in step S17 that the pressure on the powder P is equal to or greater than the predetermined value, the process proceeds to step S18. At this time, the memory unit 61 stores the measured values ​​of the impedance and porosity of the powder P in each compressed state.

[0106] In step S18, the processing unit 70 generates porosity information indicating the relationship between the impedance and porosity of the powder P based on the impedance of the powder P stored in the storage unit 61 and the porosity of the powder P corresponding to each impedance. The porosity information may be, for example, a table storing the porosity of the powder P for each measured value of the impedance of the powder P, or may be a relational expression indicating the relationship between the impedance and porosity.

[0107] Then, the processing unit 70 records the generated porosity information in the storage unit 61. Thereafter, when the measurement method shown in FIG.

[0108] Furthermore, the processing unit 70 may control the operation of the display unit 62 to display, based on the generated porosity information, the relationship between the impedance and the porosity of the powder P. Alternatively, the processing unit 70 may control the operation of the display unit 62 to display the relationship between the impedance and the porosity of the powder P that are sequentially measured in a pressure increasing state.

[0109] Fig. 11 is a diagram showing an example of a method for generating porosity information. In Fig. 11, the vertical axis represents the real part of the impedance, the horizontal axis represents the porosity, and multiple measurement results of the impedance and porosity in a pressure-rising state are shown. An approximate curve is calculated based on these measurement results, and porosity information indicating the approximate curve is generated.

[0110] As shown in FIG. 11, as the pressure applied to the powder P increases, the value of the real part of the impedance of the powder P decreases and the porosity of the powder P also decreases.

[0111] In this way, the porosity information is generated based on the impedance measured sequentially by the measuring unit 60 in a pressure increasing state in which the pressure applied by the pressure applying unit 50 to the pair of electrode units 40a, 40b is gradually increased, and the porosity calculated sequentially by the processing unit 70 in a pressure increasing state.

[0112] Next, a modification of this embodiment will be described with reference to FIG.

[0113] The measuring device 100 according to the modified example further includes a temperature adjusting unit 80 attached to the die 30 to adjust the temperature of the powder P in the receiving hole 31a.

[0114] The temperature adjustment unit 80 may have any configuration as long as it can adjust the temperature of the powder P in the containing hole 31a through the die 30. For example, as shown in FIG. 12 , the temperature adjustment unit 80 includes a liquid passage 81 provided inside the die 30 to guide the liquid, a pump 82 to circulate the liquid through the liquid passage 81, an adjustment unit 83 to adjust the temperature of the liquid circulating through the liquid passage 81, and a temperature sensor 84 as a temperature measurement unit for measuring the temperature of the powder P. The temperature sensor 84 is, for example, a thermocouple attached to the pair of electrodes 40a, 40b. The temperature sensor 84 may be provided inside the die 30. By measuring the temperatures of the pair of electrodes 40a, 40b with the temperature sensor 84, the temperature of the powder P in contact with the pair of electrodes 40a, 40b can be obtained. Alternatively, the temperature adjustment unit 80 may be a heater provided inside the die 30.

[0115] By measuring the electrical characteristics of the powder P while adjusting the temperature of the powder P using the temperature adjusting unit 80, it is possible to evaluate the characteristics of the powder P relative to temperature.

[0116] When providing such a temperature adjustment unit 80 in the die 30, it is also effective to form the inner part of the inner die 31 of the die 30 that comes into contact with the powder P from an insulating material, and to form the part that does not come into contact with the powder P from a material with high thermal conductivity such as metal. Furthermore, for example, aluminum nitride is excellent in hardness and insulating properties as well as thermal conductivity, and is therefore suitable as a material for the die 30 when the temperature adjustment unit 80 is provided.

[0117] Next, other modifications will be described.

[0118] In the above embodiment, the measurement unit 60 applies an AC signal to the electrodes 40a, 40b to perform four-terminal measurement of AC impedance. In contrast, the measurement device 100 has a two-electrode structure in which a pair of application wiring 71a, 71b and measurement wiring 72a, 72b are connected to one electrode 40a, 40b. Therefore, the measurement device 100 can also be used to measure DC resistance by applying a DC signal to the electrodes 40a, 40b. Therefore, for example, the press device 10 can be used for both DC resistance and impedance measurement by using a measurement unit 60 that can apply both DC and AC signals, or by providing a measurement unit 60 that applies a DC signal and a measurement unit 60 that applies an AC signal and switching the connections between them.

[0119] The effects of this embodiment will be described below.

[0120] The measuring device 100 for measuring powder P in this embodiment includes a memory unit 61 serving as a holder for storing porosity information indicating the relationship between the powder impedance of the powder P and the porosity of the powder P, and a die 30 having a receiving hole 31a for receiving the powder P. The measuring device 100 also includes a pair of electrodes 40a, 40b inserted into the receiving hole 31a to sandwich the powder P, a pressure unit 50 applying a high pressure load to the pair of electrodes 40a, 40b to compress the powder P, and a measuring unit 60 supplying an AC or DC electrical signal to the pair of electrodes 40a, 40b to measure the impedance of the powder P. The measuring device 100 further includes a processing unit 70 that, when the measuring unit 60 measures the impedance of the powder P, refers to the porosity information and calculates the porosity associated with the measured impedance of the powder P.

[0121] The measurement method of this embodiment is a method for measuring powder P using measurement device 100, and includes a step (S1) of retaining porosity information indicating the relationship between the impedance of powder P and the porosity of powder P, and a step (S2) of accommodating powder P in a housing hole 31a provided in a die 30 that accommodates powder P. The measurement method also includes a step (S3) of compressing powder P by applying a high pressure load to a pair of electrodes 40a, 40b that sandwich powder P, and a step (S4) of measuring the impedance of powder P by supplying an electrical signal to the pair of electrodes 40a, 40b. The measurement method further includes a step (S5) of, once the impedance of powder P has been measured, calculating the porosity associated with the measured impedance by referring to the porosity information.

[0122] Furthermore, the program of this embodiment is a program for executing the above-described measurement method, and is recorded in the storage unit 61.

[0123] According to these configurations, since the porosity information is stored, by performing impedance measurement while compressing the powder P under a high load, the porosity of the powder P can be obtained without measuring the volume of the powder P. Furthermore, since a high pressure load is applied to the powder P, the porosity can be measured in a state that is in line with the actual product state, even for powder P that is molded under a high pressure as a product.

[0124] The measured porosity of the powder P can be used as a guide when injecting an electrolyte solution in the process of impregnating the electrolyte solution into the electrodes of a battery, for example.

[0125] In addition, the measuring device 100 of this embodiment further includes a displacement sensor 55 as a displacement measuring unit that measures the relative displacement of the pair of electrode units 40a, 40b, and the processing unit 70 calculates the volume of the powder P from the thickness of the powder P obtained based on the relative displacement of the pair of electrode units 40a, 40b and the inner diameter of the storage hole 31a.

[0126] According to this configuration, the porosity of the powder P and the volume of the powder P can be obtained at the same time.

[0127] Furthermore, in the measuring device 100 of this embodiment, the processing unit 70 calculates the porosity of the powder P based on the mass and true density of the powder P and the calculated volume of the powder P. The porosity information is generated based on the impedances sequentially measured by the measuring unit 60 in a pressure-rising state in which the pressure applied to the pair of electrode units 40 a, 40 b by the pressurizing unit 50 is gradually increased, and the porosity sequentially calculated by the processing unit 70 in the pressure-rising state.

[0128] In this way, the pressure applied by the pressure applying section 50 to the pair of electrode sections 40a, 40b that sandwich the powder P is gradually increased, so that the relationship between the impedance of the powder P, which changes with pressure, and the porosity can be obtained.

[0129] Moreover, in the measuring device 100 of this embodiment, the processing unit 70 further includes a display unit 62 that displays the relationship between the impedance of the powder P and the porosity of the powder P in a pressure rising state.

[0130] According to this configuration, the measurer can grasp the relationship between the impedance of the powder P and the porosity of the powder P in real time.

[0131] In the measuring device 100 of this embodiment, the pressurizing unit 50 is configured to be able to apply a pressure of 750 MPa or more to the powder P.

[0132] According to this configuration, in a product in which the powder P is molded under high molding pressure, the electrical characteristics of the powder P can be measured in accordance with the state in which it will be used as a product.

[0133] In addition, in the measuring device 100 of this embodiment, the powder P contains a solid electrolyte. This makes it possible to easily measure the porosity of the solid electrolyte while a high load pressure is being applied by the pressure unit 50.

[0134] The measuring device 100 of this embodiment further includes a displacement sensor 55 that measures the relative displacement of the pair of electrode units 40a, 40b, and the processing unit 70 acquires the measurement results of the displacement sensor 55 and controls the operation of the measuring unit 60. When the amount of change per unit time in the relative displacement of the pair of electrode units 40a, 40b that compress the powder P becomes equal to or less than a predetermined threshold, the processing unit 70 transmits a signal to the measuring unit 60 to start measuring the impedance.

[0135] In addition, in the measurement method of this embodiment, in the process of compressing the powder P, the displacement sensor 55 measures the relative displacement of the pair of electrode portions 40a, 40b compressing the powder P, and in the measurement to measure the impedance, when the amount of change per unit time in the relative displacement of the pair of electrode portions 40a, 40b compressing the powder P becomes equal to or less than a predetermined set value, measurement of the impedance is started.

[0136] According to this measurement method, measurement is not performed when gas is contained in the powder P, and it is possible to suppress the occurrence of wasted time waiting for measurement. Therefore, the impedance measurement of the powder P can be performed accurately and efficiently.

[0137] The measurement method of this embodiment further includes a step of correcting the displacement sensor 55 that measures the relative displacement of the pair of electrode portions 40a, 40b, and a step of calculating the porosity of the powder P from the volume of the powder P acquired from the relative displacement of the pair of electrode portions 40a, 40b and the mass and true density of the powder P. The porosity information is generated based on the impedance of the powder P that is sequentially measured in a pressure-rising state in which the pressure applied to the pair of electrode portions 40a, 40b is gradually increased, and the porosity of the powder P that is sequentially calculated in the pressure-rising state.

[0138] In the step of correcting the displacement sensor 55, the relative displacement of the pair of electrode portions 40a, 40b when a predetermined first load F1 is applied while the pair of electrode portions 40a, 40b are in direct contact without the powder P sandwiched therebetween is obtained as a first measurement result, and the relative displacement of the pair of electrode portions 40a, 40b when a second load F2 larger than the first load F1 is applied while the pair of electrode portions 40a, 40b are in direct contact without the powder P sandwiched therebetween is obtained as a second measurement result, and the relationship between the load applied to the pair of electrode portions 40a, 40b and the deformation amount of the measuring device 100 is obtained based on the first measurement result and the second measurement result, and in the step of obtaining the porosity, the porosity of the powder P is calculated based on the thickness of the powder P obtained from the measurement result of the displacement sensor 55 minus the deformation amount of the measuring device 100 when the load is applied.

[0139] According to such a measurement method, the thickness of the powder P can be obtained more accurately, and therefore the porosity of the powder P can be obtained more accurately.

[0140] In addition, in the measuring device 100, each of the pair of electrode portions 40a, 40b has a plate-shaped flange portion 41a, 41b having a cross-sectional area larger than the cross-sectional area of ​​the accommodating hole 31a, and a boss portion 42a, 42b protruding from the flange portion 41a, 41b and inserted into the accommodating hole 31a.

[0141] In such a measuring device 100, the pressure force from the pressure applying section 50 can be received by the flange sections 41a, 41b, which have a relatively large pressure receiving area, and therefore the durability of the electrode sections 40a, 40b can be improved compared to when the flange sections 41a, 41b are not provided.

[0142] The measuring device 100 further includes a table 3a on which the electrode portion 40a is attached, a slider 20 on which the electrode portion 40b is attached and which moves relative to the table 3a, and mounting portions 45a and 45b formed of an insulator for mounting the pair of electrode portions 40a and 40b to the table 3a or the slider 20.

[0143] According to the measuring device 100, the electrode sections 40a and 40b can be reliably insulated from the tables 3a and 3b and the slider 20.

[0144] Furthermore, in the measuring device 100, the die 30 is made of an insulating ceramic material.

[0145] According to such a measuring device 100, the die 30 is formed of a highly durable ceramic material, and therefore, it is possible to apply a higher pressure to the powder P and measure the electrical characteristics of the powder P.

[0146] In addition, in the measurement device 100, each of the pair of electrode sections 40a, 40b is connected to application wiring 71a, 71b that guides electrical signals to be applied to the electrode sections 40a, 40b, and measurement wiring 72a, 72b that guides response signals from the electrode sections 40a, 40b.

[0147] Such a measuring device 100 has a two-electrode structure in which four electrical wires are connected to two electrodes, and therefore can be used to measure AC impedance by four-terminal measurement (four-terminal method, four-terminal pair method) in which an AC signal is applied to the electrode portions 40a and 40b, and can also be used to measure DC resistance by four-terminal measurement in which a DC signal is applied to the electrode portions 40a and 40b.

[0148] The measuring device 100 further includes a temperature adjusting unit 80 that is provided in the die 30 and adjusts the temperature of the powder P.

[0149] According to such a measuring device 100, the characteristics of the powder P can be evaluated with respect to the temperature.

[0150] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above embodiments.

[0151] For example, in this embodiment, an example has been described in which a pair of electrode portions 40a, 40b are formed to have similar shapes as shown in Figure 1, etc., but the pair of electrode portions 40a, 40b do not have to have similar shapes, and as an example, the pair of electrode portions 40a, 40b may be plate-shaped with different widths and diameters. [Explanation of symbols]

[0152] 100 Measuring Device 3a Table 20 Slider 30 Die 31a Receiving hole 40a Electrode section 40b Electrode part 41a Flange 41b Flange part 42a boss part 42b boss part 45a Mounting part 45b Mounting part 50 Pressure section 55 Displacement sensor (displacement measurement section) 57 Load sensor (load measurement section) 60 Measuring part 61 Storage section (holding section) 62 Display section 70 Processing section 71a Power supply wiring 71b Power supply wiring 72a Measurement wiring 72b Measurement wiring 80 Temperature adjustment section F1 First load F2 Second load P powder

Claims

1. A measuring device for measuring powder, a storage unit that stores information indicating a relationship between the impedance of a powder and the porosity of the powder; a die having a receiving hole for receiving the powder; a pair of electrode portions inserted into the containing holes and sandwiching the powder therebetween; a pressure applying unit that applies a high load pressure to the pair of electrodes to compress the powder; a measuring unit that supplies an AC or DC electrical signal to the pair of electrodes to measure the impedance of the powder; a processing unit that, when the measurement unit measures the impedance of the powder, refers to the information and calculates the porosity associated with the measured impedance; A measuring device comprising:

2. 2. The measuring device according to claim 1, a displacement measuring unit for measuring a relative displacement of the pair of electrode units, the processing unit calculates a volume of the powder from the thickness of the powder acquired based on the relative displacement and the inner diameter of the containing hole. Measuring equipment.

3. 3. The measuring device according to claim 2, the processing unit calculates a porosity of the powder based on the mass and true density of the powder and the calculated volume; The information is generated based on the impedances sequentially measured by the measuring unit while the pressure applied to the pair of electrode units by the pressurizing unit is gradually increased, and the porosity sequentially calculated by the processing unit while the pressure is applied to the pair of electrode units by the pressurizing unit. Measuring equipment.

4. 4. The measuring device according to claim 3, The measuring device further comprises a display unit that displays the relationship between the impedance and the porosity in the above state.

5. 2. The measuring device according to claim 1, The pressure applying unit is configured to apply a pressure of 750 MPa or more to the powder. Measuring equipment.

6. 2. The measuring device according to claim 1, The powder contains a solid electrolyte. Measuring equipment.

7. 2. The measuring device according to claim 1, a displacement measuring unit that measures the relative displacement of the pair of electrode units; The processing unit Acquire the measurement result of the displacement measurement unit and control the operation of the measurement unit; When a change amount per unit time of the relative displacement of the pair of electrode portions compressing the powder becomes equal to or less than a predetermined threshold, a signal to start measuring the impedance is transmitted to the measurement portion. Measuring device.

8. A measurement method for measuring powder using a measurement device, comprising: storing information indicating a relationship between the impedance of the powder and the porosity of the powder; a step of accommodating the powder in an accommodating hole provided in a die in which the powder is accommodated; a step of applying a high load pressure to a pair of electrodes sandwiching the powder to compress the powder; a step of supplying an electric signal to the pair of electrodes to measure the impedance of the powder; When the impedance of the powder is measured, calculating the porosity related to the measured impedance by referring to the information; A measurement method comprising:

9. The measurement method according to claim 8, a step of correcting a displacement measuring unit that measures a relative displacement of the pair of electrode units; a step of calculating a porosity of the powder from the volume of the powder obtained from the relative displacement of the pair of electrode parts, and the mass and true density of the powder, the information is generated based on the impedance measured sequentially while the pressure applied to the pair of electrode portions is gradually increased and the porosity calculated sequentially under the same conditions, In the step of correcting the displacement measuring unit, acquiring, as a first measurement result, a relative displacement of the pair of electrode portions when a predetermined first load is applied in a state in which the pair of electrode portions are in direct contact with each other without sandwiching the powder therebetween; acquiring, as a second measurement result, a relative displacement of the pair of electrode portions when a second load greater than the first load is applied in a state in which the pair of electrode portions are in direct contact with each other without sandwiching the powder therebetween; obtaining a relationship between a load applied to the pair of electrodes and a deformation amount of the measuring device based on the first measurement result and the second measurement result; In the step of calculating the void ratio, the void ratio of the powder is calculated based on the thickness of the powder obtained by subtracting the deformation amount of the measuring device when the load is applied from the measurement result of the displacement measuring unit. Measurement method.

10. A program for executing the measurement method according to claim 8 or 9.

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