Indentation test apparatus and method for indentation test

Abstract

To provide an indentation test apparatus and a method for an indentation test capable of measuring the Young's modulus and the dynamic viscoelasticity of a sample with higher accuracy.SOLUTION: The indentation test apparatus for pressing an indenter into a sample includes: an indenter; an actuator configured to displace the indenter in a vertical direction; a displacement sensor configured to measure the position of the indenter; a load measuring unit configured to measure the load applied to the indenter; a first temperature control unit configured to adjust the temperature of the indenter; and a second temperature control unit disposed below the indenter and configured to adjust the temperature of the sample.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an indentation test device and an indentation test method. [Background technology]

[0002] Indentation testing is known as a method for measuring the hardness of a sample. For example, Patent Documents 1 to 5 disclose an indentation testing device that includes an indenter, an actuator that changes the position of the indenter, a load cell that measures the load on the indenter, and the like, and an indentation testing method using the device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-88212 [Patent Document 2] Japanese Patent Application Laid-Open No. 2013-160662 [Patent Document 3] Japanese Patent Application Publication No. 2017-129557 [Patent Document 4] Japanese Patent Application Laid-Open No. 2017-203668 [Patent Document 5] Patent Publication No. 2021-103155 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide an indentation test device and an indentation test method that can more accurately measure the Young's modulus and dynamic viscoelasticity of a sample. [Means for solving the problem]

[0005] The indentation testing device according to the present invention comprises an indenter, an actuator capable of vibrating the indenter in the vertical direction, a displacement sensor that measures the position of the indenter, a load measuring unit that measures the load applied to the indenter, a first temperature adjusting unit that adjusts the temperature of the indenter, and a second temperature adjusting unit that is disposed below the indenter and adjusts the temperature of the sample.

[0006] The indentation testing device may further include a first temperature measuring unit that measures the temperature of the indenter, and a second temperature measuring unit that measures the temperature of the sample.

[0007] Any of the above indentation testing devices may further include a third temperature adjusting unit that adjusts the temperature of the load measuring unit.

[0008] In any of the above indentation testing devices, the first temperature adjustment unit and the second temperature adjustment unit may be heaters, and the third temperature adjustment unit may be a cooler.

[0009] The indentation test method according to the present invention is an indentation test method for measuring the Young's modulus of a sample, comprising the steps of: The temperature of the indenter and the temperature of the sample are adjusted, the indenter is pressed into the sample, the load applied to the indenter and the displacement of the indenter are measured, and the Young's modulus of the sample is calculated from the load and displacement.

[0010] Another indentation test method according to the present invention is a method for measuring the dynamic viscoelasticity of a sample, in which the temperature of an indenter and the temperature of the sample are adjusted, the indenter is pressed into the sample while being vibrated at a constant frequency, the load applied to the indenter and the displacement of the indenter are measured, and the storage modulus and loss modulus of the sample are calculated from the load and displacement.

[0011] Another indentation testing method according to the present invention is an indentation testing method for measuring the dynamic viscoelasticity of a sample, in which an indenter is pressed into the sample while being oscillated at a constant frequency, the load applied to the indenter and the displacement of the indenter are measured while the indenter and the sample are heated, and temperature profiles of the storage modulus and loss modulus of the sample are created from the load and displacement.

[0012] In any of the above indentation test methods, the sample may contain a thermoplastic resin and / or a curable resin. [Effects of the Invention]

[0013] The present invention provides an indentation test device and an indentation test method that can more accurately measure the Young's modulus and dynamic viscoelasticity of a sample. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic diagram showing an example of an indentation test device. [Figure 2] FIG. 10 is a schematic diagram showing another example of an indentation testing device. [Figure 3] FIG. 10 is a schematic diagram showing another example of an indentation testing device. [Figure 4] FIG. 2 is a block diagram showing an example of a control means of an indentation testing device. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same components in each embodiment are designated by the same reference numerals, and their description will be omitted or simplified. For clarity of explanation, the following description and drawings will be simplified as appropriate, and the scale of each component may differ significantly. Terms used in this specification that specify shapes, geometric conditions, and their degrees, such as "parallel," "perpendicular," "orthogonal," and "identical," are not to be construed as being limited to their strict meanings, but rather as including the range of degrees to which similar functions can be expected. Unless otherwise specified, "~" indicating a range of values ​​includes the values ​​before and after it as the lower and upper limits.

[0016] [Indentation test equipment] (First embodiment) The configuration of an indentation test apparatus will be described with reference to Fig. 1. Fig. 1 is a schematic diagram showing an example of an indentation test apparatus 100. The indentation test apparatus 100 of the first embodiment shown in the example of Fig. 1 includes an indenter 10, an actuator 20, a displacement sensor 30, a load measuring unit 40, a first temperature adjustment unit 51, and a second temperature adjustment unit 52. The shape of the indenter 10 is not particularly limited and may be selected appropriately depending on the material of the sample 90 to be measured, the purpose of the measurement, etc. One example of the indenter 10 is a spherical indenter. The material of the indenter 10 is not particularly limited, but is usually made of metal. The actuator 20 displaces the indenter 10 at least in the vertical direction (the Z-axis direction in the figure), and may be capable of vibrating the indenter 10 up and down at a constant frequency. A known actuator can be used as the actuator 20, and one example is a voice coil motor (VCM). The displacement sensor 30 measures at least the displacement in the Z-axis direction of the indenter 10. A known displacement sensor can be used as the displacement sensor 30, and one example is a voltage differential transformer (LVDT). The load measuring unit 40 measures the load applied to the indenter 10. The load measuring unit 40 may be a known unit, and one example is a load cell. The first temperature control unit 51 controls the temperature of the indenter 10. The second temperature control unit 52 controls the temperature of the sample 90. The first temperature control unit 51 and the second temperature control unit 52 may be any device that can cover the temperature range to be measured, and may be, for example, a Peltier element, or may be a heater if only heating is required. The indentation testing apparatus 100 may be supported by a support 81. In the example of Fig. 1, the actuator 20 and the displacement sensor 30 are fixed to the support 81 via arms 83 and 84. The support 81 may be fixed to a base 82, and the second temperature control unit 52 may be installed on the base 82. The sample 90 is placed on the second temperature control unit 52. If the sample 90 has fluidity, it may be placed in a container.

[0017] Next, the control means of the indentation test apparatus 100 will be described with reference to Fig. 4. Fig. 4 is a block diagram showing an example of the control means of the indentation test apparatus. The control means 70 shown in the example of Fig. 4 includes an input unit 71, an output unit 72, a calculation unit 73, a control unit 74, and a storage unit 75. The control means 70 may be a dedicated machine, or may be a known personal computer, PDA, tablet terminal, etc.

[0018] The input unit 71 is an input means for receiving input of various information for carrying out an indentation test using the indentation test apparatus 100. The input unit 71 has means for inputting at least indenter displacement information and load information applied to the indenter (for example, terminals connectable to the displacement sensor 30 and the load measuring unit 40), and may further have means for inputting temperature information from the first temperature measuring unit 61 and the second temperature measuring unit 62, and may also have a keyboard, a touch panel, various switches, etc. as necessary.

[0019] The output unit 72 is an output means for outputting various information required to carry out an indentation test using the indentation test device 100, and is configured as, for example, a monitor or the like.

[0020] The calculation unit 73 calculates the Young's modulus and dynamic viscoelasticity of the sample from information about the load applied to the indenter 10 and information about the displacement of the indenter 10. A specific example of a calculation method will be described later. Specifically, the calculation unit 73 is configured to include a CPU, various programs interpreted and executed on the CPU (including basic control programs such as an OS and application programs that are started on the OS and realize specific functions), and an internal memory such as a RAM for storing programs and various data.

[0021] The storage unit 75 is a storage means for storing various information required for processing by the control means 70, and is configured by, for example, a hard disk or other recording medium. The storage unit 75 may store, for example, information about the load applied to the indenter 10, information about the displacement of the indenter 10, information about the temperature of the indenter 10 and / or the sample 90, and the measurement time, and may also store the results calculated by the calculation unit 73. The storage unit 75 may also store the various programs described above and a program for executing the interfacial failure rate measurement method.

[0022] The control unit 74 controls at least the components constituting the indentation testing apparatus 100 and the control means 70, and may, for example, control the vibration of the actuator 20 and the temperature of the temperature adjustment units 51 to 53. Similar to the calculation unit 73, the control unit 74 is configured with a CPU, various programs interpreted and executed on the CPU, and an internal memory such as a RAM for storing the programs and various data.

[0023] The indentation testing apparatus 100 of the first embodiment described above is equipped with a first temperature control unit 51 that adjusts the temperature of the indenter 10 and a second temperature control unit 52 that adjusts the temperature of the sample 90. Therefore, for example, by adjusting the temperature of the indenter and the temperature of the sample to the same temperature, the viscoelastic properties of the sample can be measured more accurately. Furthermore, by performing similar temperature rise control on the first temperature control unit 51 and the second temperature control unit 52, a temperature profile of the viscoelastic properties of the sample can be created. For example, if the sample is a thermoplastic resin, the viscoelastic properties will differ significantly between the temperature range below the glass transition temperature and the temperature range above the glass transition temperature. Similarly, if the sample is a thermosetting resin, the viscoelastic properties will differ significantly between the temperature range below the thermosetting temperature and the temperature range above the thermosetting temperature. The indentation testing apparatus 100 of the first embodiment can also obtain accurate information on the viscoelastic properties of such samples.

[0024] (Variation 1) Fig. 2 is a schematic diagram showing another example of an indentation test apparatus. The indentation test apparatus 100 shown in Fig. 2 differs from the indentation test apparatus of the first embodiment in that it includes a first temperature measurement unit 61 that measures the temperature of the indenter 10 and a second temperature measurement unit 62 that measures the temperature of the sample 90. The first temperature measurement unit 61 measures the temperature of the indenter 10 or the temperature in its vicinity. The second temperature measurement unit 62 measures the temperature of the sample 90. The first temperature measurement unit 61 and the second temperature measurement unit 62 can be known devices, and one example is a thermocouple, and are connected to the input unit 71 of the control means 70. The indentation testing device of Variation 1 can monitor the temperatures of the indenter and the sample, making it possible to confirm whether the indenter and the sample are at the same temperature. Furthermore, when performing an indentation test under elevated temperature conditions, it is possible to automatically control the temperature adjustment units so that the indenter and the sample are heated at the same time.

[0025] (Variation 2) Fig. 3 is a schematic diagram showing another example of an indentation test apparatus 100. The indentation test apparatus 100 shown in Fig. 3 differs from the indentation test apparatus of the first embodiment in that it includes a third temperature adjustment unit that adjusts the temperature of the load measurement unit 40. The third temperature adjustment unit 53 is a member for preventing the temperature of the load measurement unit 40 from falling outside the appropriate operating temperature range of the load measurement unit. The third temperature adjustment unit 53 can suppress temperature changes in the load measurement unit 40 even when the indenter 10 is used at high or low temperatures. The third temperature adjustment unit 53 may be, for example, a Peltier element, or if the first temperature adjustment unit 51 is a heater, it may be a cooler. The cooler may be, for example, a water-cooled type that uses circulating water. The above-mentioned modifications 1 and 2 may be applied in combination with the first embodiment.

[0026] [Indentation test method] Next, the indentation test method will be explained using three examples. (Second embodiment) The indentation test method of the second embodiment is an indentation test method for measuring the Young's modulus of a sample, in which the temperature of an indenter and the temperature of the sample are adjusted, the indenter is pressed into the sample, the load applied to the indenter and the displacement of the indenter are measured, and the Young's modulus of the sample is calculated from the load and displacement.

[0027] For example, assuming that the indenter 10 is made of metal and the Young's modulus of the indenter is sufficiently larger than the Young's modulus of the sample, the Young's modulus E of the sample is expressed by the following formula (1).

[0028]

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[0029] The contact stiffness S is calculated as follows. First, a load-displacement curve (P-δ curve) is created from the load applied to the indenter and the displacement of the indenter from when the indenter is pressed into the sample until the load is released. Next, the upper half of the unloading curve is fitted to the following equation (2) to determine B, δf, and m. P = B(δ-δ f ) m (2)

[0030] Above B, δ f , and m are used to calculate the contact stiffness S using the following formula (3).

number

[0031] The contact area A is calculated by assuming the indenter to be a spherical indenter with a radius of R0 and the contact depth is calculated by δ c Then, it is expressed by the following formula (4). A=2πR0δ c (4)

[0032] When the indenter is a spherical indenter, the contact depth δc is expressed by the following formula (5). δc = δ-0.75(P / S) (5)

[0033] (Third embodiment) The indentation test method of the third embodiment is an indentation test method for measuring the dynamic viscoelasticity of a sample, in which the temperature of the indenter and the temperature of the sample are adjusted, the indenter is pressed into the sample while vibrating at a constant frequency, the load applied to the indenter and the displacement of the indenter are measured, and the storage modulus and loss modulus of the sample are calculated from the load and displacement.

[0034] The storage modulus E', loss modulus E'', and loss tangent tanφ are calculated by the following formulas (6) to (8).

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[0035] According to the indentation test methods of the second and third embodiments, the Young's modulus E, storage modulus E', and loss modulus E'' of a sample at a specific temperature (for example, 40°C or higher) can be accurately measured.

[0036] (Fourth embodiment) The indentation test method of the fourth embodiment is an indentation test method for measuring the dynamic viscoelasticity of a sample, in which an indenter is pressed into the sample, and the load and displacement of the indenter are measured while heating the indenter and the sample, and a temperature profile of the storage modulus and loss modulus of the sample is created from the load and displacement.

[0037] The methods for calculating the storage modulus, loss modulus, and loss tangent are as explained in the third embodiment. By using the indentation testing device of the first embodiment, the temperatures of the indenter and the sample can be easily adjusted, and a temperature profile of the dynamic viscoelasticity of the sample can be automatically created.

[0038] The above-described embodiments and their modifications are described as examples for the purpose of explaining the technical content of the present invention, and are not intended to limit the technical scope of the present invention to the contents of these descriptions. The technical scope of the present invention includes modifications, substitutions, additions, and omissions to the extent that a person skilled in the art can conceive of within the scope of the specification, drawings, and claims or equivalents thereto. [Explanation of symbols]

[0039] 10 indenter 20 Actuator 30 Displacement Sensor 40 Load measurement section 51 1st temperature control section 52 Second temperature control section 53 Third temperature control section 61 1st temperature measurement section 62 Second temperature measurement section 70 Control Means 71 Input section 72 Output section 73 Calculation Unit 74 Control Unit 75 Memory section 81 Post 82 Foundation 83, 84 Arms 90 samples 100 Indentation Testing Apparatus

Claims

1. An indentation testing device that indents a sample, An indenter, an actuator capable of displacing the indenter in a vertical direction; a displacement sensor for measuring the position of the indenter; a load measuring unit for measuring a load applied to the indenter; a first temperature adjusting unit that adjusts the temperature of the indenter; a second temperature control unit disposed below the indenter and controlling the temperature of the sample; An indentation test device comprising:

2. a first temperature measurement unit that measures the temperature of the indenter; The indentation testing device according to claim 1 , further comprising: a second temperature measuring unit that measures the temperature of the sample.

3. The indentation testing device according to claim 1 , further comprising a third temperature adjusting unit that adjusts the temperature of the load measuring unit.

4. 4. The indentation testing device according to claim 3, wherein the first temperature adjustment unit and the second temperature adjustment unit are heaters, and the third temperature adjustment unit is a cooler.

5. 1. An indentation test method for measuring Young's modulus of a sample, comprising: The temperature of the indenter and the temperature of the sample are adjusted. Pressing the indenter into the sample; measuring the load on the indenter and the displacement of the indenter; An indentation test method in which the Young's modulus of the sample is calculated from the load and displacement.

6. An indentation test method for measuring dynamic viscoelasticity of a sample, comprising: The temperature of the indenter and the temperature of the sample are adjusted. The indenter is pressed into the sample while being vibrated at a constant frequency, measuring the load on the indenter and the displacement of the indenter; This is an indentation test method in which the storage modulus and loss modulus of the sample are calculated from the load and displacement.

7. An indentation test method for measuring dynamic viscoelasticity of a sample, comprising: The indenter is pressed into the sample while vibrating at a constant frequency. While heating the indenter and the sample, measuring the load on the indenter and the displacement of the indenter; An indentation test method in which temperature profiles of the storage modulus and loss modulus of the sample are created from the load and displacement.

8. The indentation test method according to any one of claims 5 to 7, wherein the sample contains a thermoplastic resin and / or a curable resin.

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