Thermomechanical analysis device

Abstract

The present invention provides a thermomechanical analysis apparatus that improves the measurement accuracy when using a sample stage. The thermomechanical analysis apparatus (1) comprises: a sample stage (15) on which a sample (S) is placed; a sample tube (11) on which the sample stage is placed and fixed to the measurement system; a probe (10) extending along the axial direction (L) and having one end in direct or indirect contact with the sample to apply a load to the sample; and a heating furnace (12a, 12b) for heating the sample, wherein engaging parts (11s, 15E) are respectively provided on the sample stage and the sample tube for positioning the sample stage by engaging with each other.

Description

Technical Field

[0001] This invention relates to a thermomechanical analysis apparatus for determining the thermal behavior of a sample. Background Technology

[0002] Previously, the method of evaluating the temperature characteristics of a sample, which involves heating the sample and measuring its thermal behavior (physical changes) with temperature changes, was called thermal analysis. JIS K 0129:2005, "General Rules for Thermal Analysis," defines thermal analysis as any method that measures the physical properties of a sample by controlling its temperature using a programmed method. Commonly used thermal analysis methods include (1) Differential Thermal Analysis (DTA) for detecting temperature (temperature difference), (2) Differential Scanning Calorimetry (DSC) for detecting heat flow difference, (3) Thermogravimetric Analysis (TG) for detecting mass (weight change), (4) Thermomechanical Analysis (TMA) for detecting mechanical properties, and (5) Dynamic Viscoelasticity Measurement (DMA).

[0003] Thermomechanical analysis (TMA) involves applying a load to a sample using a probe and detecting the shape change of the sample as the displacement of the probe (see, for example, Patent Documents 1 and 2). This allows the elastic modulus and coefficient of thermal expansion of the sample to be determined as functions of temperature or time.

[0004] Here, the thermomechanical analysis apparatus (TMA) has a sample tube (reference tube) fixed to the measurement system, on which a sample is placed directly or indirectly, either above the sample tube or across the sample stage. Furthermore, various measurements are performed by applying a load to the sample by bringing a probe into contact with it.

[0005] The sample tube (reference tube) is usually cylindrical. With the sample inside or on top, the sample is pressed by a probe, which enables expansion / compression and needle penetration measurement modes.

[0006] Additionally, as described in Patent Document 2, sometimes a sample tube 11 is provided on its side. Figure 3 The opening 11k shown can be used, or a slit 11s can be provided on the bottom surface of the sample tube 11. Alternatively, the chuck 4b can be fixed in the slit 11s, and the membrane sample S2 can be held by the chucks 4a and 4b for tensile testing.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent No. 2909922

[0010] Patent Document 2: Japanese Patent No. 3370620 Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] However, as described in Patent Document 1, sometimes a sample stage is placed on the sample tube, and the sample is placed on the sample stage. If the sample is placed on the sample tube via the sample stage, the sample tube and the sample do not come into direct contact, thus suppressing sample tube contamination.

[0013] However, when setting up the sample, the sample stage may move, or the measurement accuracy may be reduced due to slight vibrations caused by moving the sample tube up and down after the sample is set up, or by closing the furnace surrounding the sample tube.

[0014] The present invention was made to solve the above-mentioned problems, and its purpose is to provide a thermomechanical analysis device with improved measurement accuracy when using a sample stage.

[0015] Methods for solving problems

[0016] To achieve the above objectives, the thermomechanical analysis apparatus of the present invention comprises: a sample stage on which a sample is placed; a sample tube on which the sample stage is placed and fixed to a measurement system; a probe extending axially and having one end of itself in direct or indirect contact with the sample to apply a load to the sample; and a heating furnace for heating the sample. The thermomechanical analysis apparatus is characterized in that engaging portions are respectively provided on the sample stage and the sample tube for positioning the sample stage by engaging with each other.

[0017] According to this thermomechanical analysis device, the sample stage can be positioned at a specified position on the sample tube by means of the locking part, and the sample stage can be firmly locked to the sample tube. Therefore, the movement of the sample stage is suppressed during the measurement, and the measurement accuracy is improved when using the sample stage.

[0018] In the thermomechanical analysis apparatus of the present invention, a gap for locking a chuck for tensile testing may be formed on the bottom surface of the sample tube, the gap being one of the engaging portions, the sample stage being placed on the bottom surface of the sample tube, and a protrusion that engages with the gap being formed on the bottom surface of the sample stage as the other engaging portion.

[0019] According to this thermomechanical analysis apparatus, the present invention can also be effectively applied to sample tubes that can be used for tensile testing.

[0020] Invention Effects

[0021] According to the present invention, a thermomechanical analysis apparatus with improved measurement accuracy when using a sample stage can be obtained. Attached Figure Description

[0022] Figure 1This is a diagram showing the structure of a thermomechanical analysis apparatus according to an embodiment of the present invention.

[0023] Figure 2 This is a three-dimensional view of the sample tube.

[0024] Figure 3 This is a perspective view showing an example of using a sample tube for tensile testing.

[0025] Figure 4 This is a three-dimensional view of the sample stage.

[0026] Figure 5 This is a three-dimensional view showing a modified example of the sample stage.

[0027] Figure 6 It means to Figure 5 A top view of the sample stage placed on the sample tube.

[0028] Figure 7 This is a perspective view showing another variation of the thermomechanical analysis apparatus and sample stage.

[0029] Label Explanation

[0030] 1: Thermomechanical analysis apparatus;

[0031] 10, 100: Probes;

[0032] 11, 110: Sample tubes;

[0033] 11b: Bottom surface of the sample tube;

[0034] 11s, 15E, 11f, 150w, 110p, 250r: Connecting parts;

[0035] 11s: Engaging part (gap);

[0036] 15E: Engaging part (protrusion);

[0037] 12a, 12b: Heating furnace;

[0038] S: Sample;

[0039] L: Axial direction. Detailed Implementation

[0040] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0041] Figure 1 This is a diagram showing the structure of the thermomechanical analysis apparatus 1 according to an embodiment of the present invention.

[0042] The thermomechanical analysis apparatus 1 includes: a sample stage 15 on which a sample S is placed; a sample tube 11 on which the sample stage 15 is placed and fixed to the measurement system (frame 14); and a rod-shaped probe 10 extending along the axial direction L ( Figure 1 The probe 10 extends in the vertical direction; a load generator 5 generates a load along the axial direction L of the probe 10; a load transfer shaft 17 connects the load generator 5 to the probe 10; displacement detectors 6a to 6b detect the displacement of the probe 10 along the axial direction L; and heating furnaces 12a and 12b are used to heat the sample S.

[0043] The components of the thermomechanical analysis apparatus 1 are supported by the frame 14. In addition, a bottomed cylindrical sample tube (also called a reference tube or sample holding component) 11 is erected from the frame 14 downwards (towards the sample S), and a cylindrical sample stage 15 is placed on the bottom surface 11b of the sample tube 11.

[0044] Moreover, in this example, one end (lower end) of the probe 10 is in direct contact with the upper end of the sample S placed on the sample stage 15, thereby applying a load to the sample S.

[0045] Furthermore, a thermocouple 22 for temperature measurement is placed near the sample S.

[0046] The load transmission shaft 17 is a rod-shaped structure extending along the axial direction L. The upper end (one end) is fixed (connected) to the load generator 5, and the lower end (the other end) is provided with a connecting joint 17c.

[0047] Although not illustrated, the load generator 5 has a coil and a magnetic circuit consisting of a permanent magnet surrounding the coil. By the flow of current in the coil, the load generator 5 is displaced along the axial direction L to generate a load.

[0048] On the other hand, a probe connector 10c is connected to the other end (upper end) of the probe 10, and the load of the load generator 5 is transferred to the probe 10 by connecting the connector 17c to the probe connector 10c.

[0049] In addition, probe 10 is coaxially connected to load transfer shaft 17.

[0050] Additionally, along the axial direction L, a conductor-made iron core (magnetic material) 6b is fixed to the outer periphery of the portion between the connecting joint 17c in the load transmission shaft 17 and the load generator 5. A differential transformer (primary coil and secondary coil) 6a is arranged around the iron core 6b. Furthermore, a detector 6c detects the voltage of the differential transformer 6a.

[0051] Furthermore, since the length of the sample S changes due to thermal expansion when the temperature changes, the position of the core 6b (and thus the probe 10) relative to the differential transformer 6a changes. At this time, a voltage is generated in the differential transformer 6a corresponding to the displacement, so the axial displacement L of the core 6b (and thus the probe 10) can be detected.

[0052] These differential transformers 6a and iron core 6b constitute a "displacement detector".

[0053] A heating furnace consisting of a furnace body 12a and a heater 12b disposed around the furnace body 12a is provided around the sample S. The temperature of the heating furnace is controlled by a specified control unit.

[0054] The load signal generator 20 generates a load signal that causes the load generator 5 to operate. The load signal generator 20 is, for example, an electronic circuit formed by mounting various electronic components and chips on a circuit board.

[0055] The load signal generator 20 outputs an analog signal to the load generator 5 to generate a specified load.

[0056] The load generated by the load generator 5 is applied to the sample S via the load transfer shaft 17 and the probe 10.

[0057] On the other hand, the displacement generated in the sample S due to the load is transmitted to the core 6b through the probe 10 and the load transfer shaft 17, and is detected as the displacement of the core 6b relative to the differential transformer 6a.

[0058] The displacement detection signal generated by the differential transformer 6a and the iron core 6b is sent to the detector 6c and converted into a displacement signal.

[0059] The displacement signal, which is the output of detector 6c, is sent to arithmetic unit 9, and together with the load signal previously input to load signal generator 20, the physical quantity (mechanical property) of sample S is calculated.

[0060] Specifically, in this example, as a thermomechanical analysis (TMA), a load is applied to the sample S by probe 10, and the shape change (length change, etc.) of the sample S at this time is determined as a physical quantity.

[0061] Furthermore, this invention focuses on various measurements (such as linear thermal expansion rate, glass transition temperature, etc.) under expansion / compression and needle penetration measurement modes, but does not include tensile measurements.

[0062] Here, as Figure 2 As shown, the sample tube 11 is generally cylindrical and extends along the axial direction L. It has an opening 11k at the front of the side of the sample tube 11 and a rectangular opening slit 11s is provided on the bottom surface 11b of the sample tube 11.

[0063] In addition, the side 11w of the sample tube 11, excluding the opening 11k, surrounds the bottom surface 11b in an arc shape. Furthermore, a slit 11s is provided on the side of the bottom surface 11b facing the opening 11k.

[0064] Furthermore, the sample stage 15 is placed on the bottom surface 11b in a manner that covers the gap 11s.

[0065] Furthermore, the setting and replacement of sample S are performed by opening the heating furnace, lowering the sample tube 11 and removing it from the opening 11k to insert the sample S. Afterwards, the sample tube 11 is moved to the appropriate position according to the axial length L of the sample S, and the heating furnace is turned off to carry out the measurement.

[0066] In addition, such as Figure 3 As shown, in this embodiment, the sample tube 11 can be used for tensile testing. However, as described above, tensile testing is not the focus of this embodiment.

[0067] Next, the characteristic features of the present invention will be described.

[0068] like Figure 2 , Figure 4 As shown, in the thermomechanical analysis apparatus 1 of the present invention, a rectangular protrusion 15E is provided on the opposite side (lower surface) of the contact surface (upper surface) 15a of the sample stage 15 that contacts the sample S. The shape of the protrusion 15E is slightly smaller than the size of the gap 11s on the bottom surface 11b of the sample tube 11.

[0069] Therefore, as Figure 2 As shown, when the protrusion 15E of the sample stage 15 is inserted into the cut portion of the slit 11s so that the sample stage 15 covers the bottom surface 11b of the sample tube 11, the protrusion 15E and the slit 11s engage and lock into each other.

[0070] Therefore, the sample stage 15 can be positioned at the specified position of the sample tube 11 and the sample stage 15 can be firmly fixed to the sample tube 11, thus improving the measurement accuracy when using the sample stage 15.

[0071] Furthermore, the protrusion 15E and the gap 11s are respectively equivalent to the "engaging part" in the claims.

[0072] Furthermore, if the sample stage 15, sample tube 11, and probe 10 are made of the same material, the measurement error will be minimized, which is therefore preferred. Examples of materials for the sample stage 15, sample tube 11, and probe 10 include quartz glass and alumina.

[0073] Furthermore, in the above embodiment, the protrusion 15E and the gap 11s were described as examples of "engaging parts", but the gap 11s may also be a concave shape that engages with the protrusion 15E.

[0074] Figure 5 , Figure 6 This shows a variation of the sample stage 150.

[0075] like Figure 5 , Figure 6 As shown, the sample stage 150 integrally comprises: a circular plate-shaped base portion 150m having a contact surface (upper surface) 150a that contacts the sample S; and a sidewall portion 150w extending from a portion of the outer periphery of the base portion 150m (in... Figure 5 The middle section (roughly a semi-circular part near the front of the paper) is placed downwards.

[0076] Furthermore, when the sample stage 150 is inserted from the opening 11k of the sample tube 11 so that the sample stage 150 covers the bottom surface 11b of the sample tube 11, the semi-circular side wall portion 150w contacts the semi-circular front wall portion 11f of the bottom surface 11b of the sample tube 11 from the outside.

[0077] Therefore, the sample stage 150 can be positioned at the specified position of the sample tube 11 and the sample stage 150 can be firmly locked to the sample tube 11, thus improving the measurement accuracy when using the sample stage 150.

[0078] Furthermore, the side wall portion 150w and the front wall portion 11f are respectively equivalent to the "engaging portion" in the claims.

[0079] Figure 7 This represents another variation of the thermomechanical analysis apparatus and the sample stage 250.

[0080] Here, Figure 7 The thermomechanical analysis apparatus, apart from the structure of the sample tube 110 and the probe 100, is similar to... Figure 1 The thermomechanical analysis apparatus is the same as 1, therefore descriptions of other structures are omitted.

[0081] like Figure 7 As shown, the sample tube 110 is cylindrical, and the sample S is placed on its upper side (facing upward) 110a via the sample stage 250.

[0082] On the other hand, the probe 100 as a whole is oriented along the axial direction L ( Figure 1 The probe 100 is a rod-shaped part extending in the vertical direction, with one end (the upper end) bent downwards into a U-shape. Furthermore, a load generator is located on the lower side of the probe 100. When the probe 100 is pressed downwards by the load generator, the upper end 100s of the U-shaped probe 100 applies a downward load to the sample S.

[0083] Here, a cylindrical protrusion 110p is provided on the upper surface (contact surface in contact with the sample) 110a of the sample tube 110. On the other hand, the sample stage 250 is in the shape of a circular plate, and a circular recess 250r is formed on its lower surface (the surface opposite to the upper surface 110a). The diameter of the recess 250r is slightly larger than that of the protrusion 110p.

[0084] Furthermore, by covering the sample stage 250 over the upper surface 110a of the sample tube 110, the recess 250r and the convex portion 110p are fitted together.

[0085] Therefore, the sample stage 250 can be positioned at the specified position of the sample tube 110 and the sample stage 250 can be firmly locked to the sample tube 110, thus improving the measurement accuracy when using the sample stage 250.

[0086] Furthermore, the recess 250r and the convex portion 110p are respectively equivalent to the "engaging portion" in the claims.

[0087] The present invention is not limited to the embodiments described above.

[0088] For example, there are no restrictions on the shape of the sample stage or sample tube.

[0089] Furthermore, there are no restrictions on the number or shape of the engaging parts.

Claims

1. A thermomechanical analysis apparatus, comprising: A sample stage on which the sample is placed; A sample tube, which is placed on the sample stage and fixed to the measuring system; A probe, extending axially, has one end in direct or indirect contact with the sample, applying a load to the sample; and A heating furnace, used to heat the sample. The thermomechanical analysis device is characterized in that... The sample stage and the sample tube are respectively provided with engaging parts that engage with each other to position the sample stage.

2. The thermomechanical analysis apparatus according to claim 1, characterized in that, A slit is formed on the bottom surface of the sample tube for locking the chuck used in the tensile test. The gap becomes one side of the engaging portion. The sample stage is placed on the bottom surface of the sample tube, and a protrusion that fits into the gap is formed on the bottom surface of the sample stage as the other side of the engaging part.

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