What Is a Metallurgical Microscope?

Computerized metallographic microscope or digital metallographic microscope is a high-tech product developed by perfect combination of optical microscope technology, photoelectric conversion technology and computer image processing technology, which can easily observe metallographic images on a computer , So as to analyze the metallographic atlas, rating, etc. and output and print the pictures.

Metallographic microscope system is a traditional

Optical system: ICCS optical system, lens body: FEM design, ACR position coding

1. Material multiples: 5X 10X 20X 50X 100X optional 1.25X, 2.5X, 150X

2. Eyepiece multiple: 10X

3. Field of view: 20, 22

4. Objective lens turntable: 5 holes

5. Observation function: bright field, dark field, simple polarized light, differential interference

6. Light source: 12V 50W halogen lamp

7, scalability: can be equipped with image analysis system (digital camera, camera, image analysis software

Computerized metallographic microscope: 1. Metallographic microscope 2. Adapter lens 3.

Metallography mainly refers to the branch of materials that analyzes and studies material microstructures, low magnification tissues and fracture tissues with the help of optical (metallurgical) microscopes and stereo microscopes. Quantitative characterization also includes the necessary sample preparation, preparation, and sampling methods. It mainly reflects and characterizes the phase and structure composition of constituent materials, grains (including possible sub-crystals), non-metallic inclusions, and even the number, morphology, size, distribution of certain crystal defects (such as dislocations), Orientation, spatial arrangement, etc.

Features:

1. The world's best infinity dual color correction and contrast enhanced (ICCS) optical system is used to provide users with the sharpest images.

2. The combination of 5 kinds of upper parts, 3 kinds of lower parts, and two columns can be combined according to your requirements for material testing and economic cost. It can realize the analysis of transparent materials, opaque materials and fluorescent materials. At the same time, it has a powerful upgrade space to ensure your future testing requirements.

3. The industry's largest design height can reach 380 mm, providing you with extraordinary operating space.

4. Close to the user's flexibility, no need for professionals to upgrade the components of the equipment, users can complete the operation by themselves.

1. According to the magnification required to observe the sample, the objective lens and eyepiece are correctly selected and installed on the objective lens holder and the eyepiece tube, respectively.

2. Adjust the center of the stage to the center of the objective lens, and place the prepared sample on the center of the stage. The observation surface of the sample should face down.

3. Insert the bulb of the microscope on the low voltage transformer (6 ~ 8V), and then plug the transformer plug into the 220V power socket to make the bulb bright.

4. Turn the coarse focus handwheel to lower the stage so that the specimen observation surface is close to the objective lens; then turn the coarse focus knob in the opposite direction to raise the stage so that the blurred image can be seen in the eyepiece; finally, rotate the fine adjustment Focus the handwheel until the image is sharpest.

5. Appropriately adjust the aperture stop and the field stop, and select the appropriate filter to obtain the ideal object image.

6. Move the stage back and forth, left and right, observe different parts of the sample, in order to comprehensively analyze and find the most representative microstructure.

7. After observing, the power should be cut off in time to extend the life of the bulb.

8. After the experiment, you should carefully remove the objective lens and eyepiece, and check for dust and other contamination. If there is any contamination, you should wipe it clean with lens paper in a timely manner, and then store it in a desiccator to prevent moisture and mildew. . The microscope should also be covered with a dust cover at all times.

To ensure the service life and reliability of the system, note the following:

1. The laboratory should be equipped with three protection conditions: shockproof (away from the source), moisture-proof (using air conditioners, dryers), dust-proof (pave the floor); power supply: 220V + -10%, 50HZ temperature: 0 degrees -40 degrees

2. Be careful not to let the objective lens touch the specimen when focusing, so as not to scratch the objective lens.

3. When the center of the round hole of the stage pad is far from the center of the objective lens, do not switch the objective lens to avoid scratching the objective lens.

4. The brightness adjustment should not be too big or too small, and it should not be too bright, affecting

The improvement of metallographic microscope mainly includes the following:

Infinity optical system

The objective lens is designed according to the infinite distance, instead of the limited distance like the conventional objective lens. This kind of optical system is called the infinity chromatic aberration and aberration correction optical system or infinity optical system for short. When using this optical system , when

People often come into contact with general metallographic microscopes, which are mainly used for testing metallographic structures of metal surface machines. They are widely used and play an indispensable and important role in experiments and research for enterprises, metallurgy and other departments. There are many manufacturers of metallographic microscopes, and their models and specifications are not uniform. Therefore, there is no national, local, or departmental inspection procedure for metallographic microscope testing. Therefore, we test them according to national standards.

Objective lens positioning error

Check fixture:

(1) 10x cross eyepiece.

(2) A scribe rule with a scribe value of 0.01mm, and the limit deviation between any two scribe lines is ± 0.005mm.

Detection method: Install a 40x objective lens on the converter of the metallographic microscope to be tested, put a 10x cross eyepiece in the eyepiece tube, and focus on the 0.01mm scribe ruler placed on the stage to make the scribe ruler clear. The reticle coincides with the center of the reticle in the eyepiece, then rotate the objective lens to the left and right for multiple positioning (not less than 3 times), observe the shift of the 0.01mm reticle image, and use the maximum offset value as the detection value.

Technical requirements: not more than 0.02 mm.

Objective lens deviation

Check fixture:

(1) 10x cross reticle eyepiece.

(2) Two-letter reticle.

Detection method: Use a 10-fold crosshair eyepiece and various magnification objective lenses to perform detection on the inspected microscope, and use the maximum deviation as the detection value.

Technical requirements: Do not exceed the field of view when switching from a 10x objective to other magnification objectives.

Stage rotation center offset

Check fixture:

(1) 10x cross reticle eyepiece.

(2) Two-letter reticle.

Detection method: On the metallurgical micrometer under test, use a 10x cross reticle eyepiece and a 10x objective lens to focus the cross reticle placed on the stage clearly. Move the cross reticle while rotating the stage. The image at the center of the crosshairs tends to the smallest circle, and the diameter of the smallest circle is used as the detection value.

Technical requirements: The maximum deviation of the center of the first image of the microscope is not greater than 0.2mm.

Eyepiece deviation

Check fixture: cross reticle.

Detection method: Use a 10x objective lens and the cross reticle eyepiece on the microscope to focus the cross reticle placed on the stage clearly, and make the image of the center of the cross reticle coincide with the cross reticle eyepiece. Then rotate the reticle eyepiece and use the maximum offset of the two reticle centers as the detection value.

Technical requirements: The center of the crosshair of the cross-dividing eyepiece should coincide with the ascending circle axis of the eyepiece, and its deviation is 0.01mm.

Problems in the imaging section are more serious.

1.Optical system

(1) The field of view is blurred or as unclear as the field of view.

(2) The image flickers and the contrast is not good.

(3) Less than confocal when changing objective lens.

(4) Even with high voltage, the field of view is difficult to be sharp.

2. Coarse and fine-tuning department

(1) The coarse adjustment knob is heavy when rotated.

(2) The focus during observation is moved away due to the natural lowering of the stage or the sliding of the coarse adjustment.

3. Binocular tube The field of view of the binocular tube is inconsistent.

The above problems are easy to correct, basically accurate and reliable.

1. Where conditions permit, it is recommended that the laboratory should have three protection conditions: shockproof, moisture-proof and dust-proof; power supply: 220V ± 10%, 50HZ; temperature: 0 ° C-40 ° C.

2. The brightness adjustment should not be changed suddenly, and it should not be too bright, which will affect the service life of the light bulb and damage the eyesight.

3. All (function) switch, the action should be light and in place.

4. Turn the brightness to the minimum when shutting down.

5. Be careful not to let the objective lens touch the sample when focusing, so as not to scratch the objective lens.

6. Do not switch the objective lens when the center of the round hole of the stage pad is far from the center of the objective lens, so as not to scratch the objective lens.

7. Non-professionals should not adjust the lighting system (filament position light) to avoid affecting the imaging quality.

8. When replacing the halogen lamp, pay attention to the high temperature to avoid burns; be careful not to touch the glass body of the halogen lamp directly with your hands.

9. When not in use, turn the objective lens to the lowest state through the focusing mechanism.

10. When not in use, do not cover the dust cover immediately, cover it after cooling down, pay attention to fire prevention.

The metallographic microscope mainly analyzes the relationship between the structure of the steel and its chemical composition through the inspection of the structure and morphology; it can determine the microstructure of various types of steel after different processing and heat treatment; to judge the quality of the steel Bad, such as the distribution and quantity of various types of steel inclusions-oxides, sulfides, etc. in the structure, and the size of the metal grain size.

Research on Steel Structure and Phase

After the etching treatment, the sub-microstructure of the steel can be observed with a metallographic microscope. In most cases, the grain boundaries are diffusely reflected so they cannot enter the objective lens, so the grain boundaries appear mostly black. The structure of the steel is divided by the grain boundary. The qualitative analysis of the steel can be performed based on the test results, including: the structure morphology, grain size, non-metallic impurities-oxides, sulfides, etc. And distribution; the relationship between the structure of the material and its chemical composition; the microstructure of various materials after different processing processes can be determined; the quality of the material can be judged. The malleable cast iron is annealed, and the graphite has a black floc structure, similar to cotton wool, and has a more regular shape. No etching was performed and the substrate appeared white. The test sample was a white cast iron green body. It can be obtained by subjecting the primary, secondary, and tertiary cementite to sufficient graphitization through annealed solid-state graphitization. Under the metallographic microscope, graphite is a black sheet-like structure. Because it has not been etched, it is basically not shown. It is white. Graphite is mainly dispersed in a single sheet on the substrate. . The length of flake graphite is different, and its performance is also different.

Analysis of steel impurities

The analysis of impurities using metallographic microscopes is mostly quantitative. The bright field is used to observe the color, shape, size and distribution of the impurities; the dark field is used to observe the inherent color and transparency of the impurities; using polarized light Various orthogonal optical properties are used to observe impurities, and then to judge the type of impurities. In most cases, silicates show a solitary shape distribution, oxides such as alumina, ferrous oxide, and manganese hydroxide are clustered into clusters, while ferrous sulfide and ferrous sulfide · ferrous oxide It is distributed along the grain boundaries.

Phase difference analysis of polarized light microscope

In the steel structure, sometimes the performance of the reflected light is the same or similar, and the surface height is only a small structure. The two types of tissues show that when the incident light waves are reflected on them, the amplitudes of the two types are basically the same, but their phases are different. It is difficult for the naked eye to distinguish such reflected light with the same amplitude but different phase differences. The solution is to use a ring-shaped diaphragm and a phase plate. The transmitted light reflects or lags 1/4 of the wavelength to produce a positive or negative phase difference. That is, the light of the peripheral phase difference is converted into light of poor intensity, thereby improving the discrimination ability .