JPH04313046A - Method and apparatus for observing broken state of sheet-shaped material - Google Patents

Abstract

PURPOSE:To perform the processing for obtaining a conduction and observation under the state wherein stress is applied by using a material testing apparatus which can be attached to an ordinary electron microscope and wherein stress can be changed. CONSTITUTION:A sheet-shaped sample 4 is held with pushing plates 3a and 3b to a fixing stage 1 and moving stage 2. The sample 4 is fixed with sample fixing screws 5a and 5b. Then, a stress adjusting screw 6 is adjusted, and the distance between the fixing stage 1 and the moving stage 2 is changed. Stress is applied on the sample 4 in this way. With this state being maintained, the processing for conducting the sample 4 is performed, and the sample is observed with an ordinary electron microscope.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a method and apparatus for observing the fracture form of a sheet-like object by microscopic observation while applying an arbitrary stress to a sample in order to observe and analyze the fracture form of a sheet-like object. .

0002

[Prior Art] When applying stress to a sheet-like material using a general material testing machine and then observing it using an electron microscope, it is necessary to remove it from the material testing machine and release the stress. could not. Molding processing of literature Part 3
Vol. 1, 1991, P.7 states, ``Conventionally, in order to clarify the deformation of polymer alloys containing rubber, ultra-thin sections were taken from test specimens whose loading was interrupted in the middle of deformation, or from test specimens after fracture. The rubber particles were cut out and stained with osmium oxide to provide contrast, and a transmission electron microscope was used to observe the state of crazes or voids. After the specimen was destroyed, the load was interrupted, the specimen was taken out, made conductive, and placed on a sample stage in an electron microscope for observation.

[0003] Material testing machines sold by analytical equipment manufacturers are available as devices for utilizing the observation and investigation of the fracture process of materials for material performance evaluation. This device is suitable for investigating the fracture process of materials where the observation point moves little due to elongation, such as metal materials, when observed under an electron microscope, but it is not suitable for plastics, etc., where the observation point moves due to elongation. Furthermore, when observing plastic materials with low conductivity, metal vapor deposition is generally applied to prevent charge-up phenomena. In particular, metal vapor deposition is essential for observation at high magnification exceeding 1000 times. Furthermore, conventional material testing machines are large, dedicated devices that cannot be attached to general electron microscopes.

0004

[Problems to be Solved by the Invention] The purpose of the present invention is to create a small material that can be installed in the sample chamber of a general electron microscope, allowing observation under stress, which could not be observed without using conventional large dedicated equipment. It is an object of the present invention to provide a method and apparatus that allow easy observation under stress using a testing device.

[0005]

[Means for Solving the Problems] As a result of intensive studies to achieve the above object, the present inventors have found that in order to observe and investigate the fracture form when the sample material is actually used,
It is necessary to put it in the state in which it is actually used within the electron microscope. After making the sample conductive by freeing tensile and compressive stress, we observe that when the stress is released, stress relaxation etc. may occur and the shape may change.
It is inappropriate for actual material evaluation. Based on this, we created a method and material testing device that allow conductivity treatment and observation without releasing stress, and arrived at the present invention.

That is, the present invention is a method of applying tensile stress or the like to a sheet-like material and observing its fracture form using a microscope. Destruction of a sheet-like object characterized by fixing both ends of the specimen to a fixed table and a moving table, then moving the moving table to apply stress to the sample piece, and observing it under a microscope with the amount of change arbitrarily adjusted. This is a morphological observation method.

[0007] In addition, in an apparatus that applies tensile stress or the like to a sheet-like object and observes its fracture form using a microscope, stress can be applied to a sample piece in the sample chamber of the microscope, and the amount of change can be arbitrarily adjusted. This is an apparatus for observing the fracture morphology of a sheet-like object, which is equipped with a material testing apparatus having a fixed table and a movable table for a sample piece that can maintain stress.

The present invention will be explained in more detail below. In order to observe the morphology of the sheet-like article of the present invention under stress, one end of the sample piece is completely fixed on a fixing table using, for example, a holding plate or a direct fixing screw or vise. Completely fix the other end to the moving base in the same way as fixing it to the fixed base.

[0009] The distance between the fixed base and the movable base when no stress is applied, or the set length of the sample piece, is measured on an appropriate scale, and the distance between the fixed base and the movable base is measured using, for example, a stress adjustment screw, motor, hydraulic pressure, etc. Adjust the stress applied to the sample by moving the moving stage using a cylinder, etc.

At this time, it is necessary to prevent the moving stage from wobbling or twisting due to the elasticity of the sample. For example, it is preferable to use a rail on which the movable platform slides in parallel or an auxiliary bar to prevent twisting. In addition, when using a transmission microscope, set up an observation port at the sample observation position, i.e., on a fixed stand directly below the sample, so that it can be observed with the transmission microscope, and place the rails, stress adjustment screws, etc. so that they do not interfere with observation. It is preferable to provide a plurality of them.

[0011] In addition, it is preferable to install, for example, a fixing screw to completely fix the movable table at a position where an arbitrary stress is applied.

0012

[Embodiment] An embodiment of the method and apparatus for observation using a small-sized material testing device that can be easily installed on a general sample stage for an electron microscope according to the present invention will be described below with reference to the drawings. FIG. 1 is a schematic front view of a material testing device according to the present invention, and FIG.
is a schematic side view of the same, Figure 3 is an electron micrograph (300x magnification) under stress, Figure 4 is an electron microscope photograph (5000x magnification) under stress, and Figure 5 is an electron microscope photograph (5000x magnification) under stress. This is an electron micrograph (magnification: 5000x) taken after removal and stress relaxed.

A sheet-like sample 4 is sandwiched between the fixed table 1 and the movable table 2 in FIG. Stress is applied to sample 4 by changing the distance between the two. Stress adjustment can be confirmed on the scale 7 at the bottom of the moving table 2. Tighten the stress adjustment screw fixing screw 8 after adjusting the strain. Moving table fixing screw 9
I'll close it later. The rail 12 was provided for the purpose of preventing the sample and the moving stage from shaking or twisting.

FIG. 3 shows a high nitrile resin manufactured by Mitsui Toatsu Chemical Co., Ltd. (product name: Zekron (thickness: 0.5 mm)) using this device.
Conductive treatment is performed while applying 20% tensile stress.
This is a photograph observed with an electron microscope (300x magnification). It is easily seen that the sample is stretched in the direction of the tensile stress and cracks are generated in the direction perpendicular to the direction of the tensile stress.

FIG. 4 is a photograph of the same sample as in FIG. 3 observed at high magnification (5000x magnification) in order to observe more details.
It can be seen that many crazes gathered together to form a crack.

FIG. 5 shows 20 pieces of Zekron (thickness 0.5 mm).
This is a photograph taken after a tensile test was performed, removed, subjected to conductive treatment in a stress-relaxed state, and observed with an electron microscope (magnification: 5000x). Although traces of cracks can be seen from this photograph, it is clear that the shape has changed due to stress relaxation and the most important crazes that should be observed cannot be observed.

[0017]

Effects of the Invention As shown in the examples, the present invention uses the material testing device of the present invention that can be attached to a general electron microscope and has variable stress, so that stress is applied during the process from conductivity treatment to observation. This makes it possible to capture phenomena that could not be observed with conventional measurement methods, and enables observation of details at lower magnification than with conventional techniques.

[Brief explanation of drawings]

FIG. 1 is a schematic front view of a material testing device according to the present invention.

FIG. 2 is a schematic side view of a material testing device according to the present invention.

FIG. 3 is an electron micrograph (300x magnification) under stress using the material testing device according to the present invention.

FIG. 4 is an electron micrograph (magnification: 5000 times) in a state where stress is applied using the material testing device according to the present invention.

[Figure 5] is an electron micrograph (magnification: 50
00 times).

[Explanation of symbols]

1: Fixed base 2: Moving base 3a, 3b: Holding plate 4: Sheet sample 5a, 5b, 5c, 5d: Fixing screw 6: Stress adjustment screw 7: Scale 8: Fixing screw for stress adjustment screw 9: Moving base fixing Screw 10: Bearing 11: Bearing 12: Rail

Claims (2)

[Claims] Claim 1: A method of applying tensile stress or the like to a sheet-like material and observing its fracture form using a microscope, comprising: providing a material testing device having a fixed stage and a moving stage in a sample chamber of the microscope;
A sheet-like object characterized by fixing both ends of a sample piece to a fixed table and a moving table, moving the moving table to apply stress to the sample piece, and observing it under a microscope with the amount of change arbitrarily adjusted. Method for observing fracture morphology. [Claim 2] A device for applying tensile stress or the like to a sheet-like object and observing its fracture form using a microscope. 1. An apparatus for observing the fracture morphology of a sheet-like object, comprising a material testing apparatus having a fixed table and a movable table for a sample piece that can maintain stress.