Table of ContentsIntroductionTheoryMaterials and DevicesProcedureDiscussionPossible ErrorsPossible ImprovementsConclusionObserve the constituents and structure of metals and their alloys using an optical microscope.Say no to plagiarism. Get a tailor-made essay on “Why Violent Video Games Should Not Be Banned”? Get the original essayIntroductionIt involves examining the microstructure of steel and observing its constituents and structure. Microstructure refers to the structure that requires high magnification to be visible. To examine the microstructure of steel, microscopes are needed. The conventional optical microscope is commonly used, as well as an optical microscope to examine the samples. However, we use the optical microscope, not the conventional optical microscope, to examine the surface of the specimens, because many materials do not transmit light. Microscopes can provide information about the particular characteristics of a material with regard to composition, processing and material properties. . We examine the microstructure of the steel using the optical microscope after grinding, polishing and applying the necessary chemicals to remove impurities from the steel sample. It is very important to prepare the sample correctly. Theory There are certain procedures to follow before examining the microstructure of steel. These are grinding, polishing, engraving and mounting. The steel sample must first be ground using rotating discs covered with silicon carbide paper and water. It is necessary to apply light pressure to the center of the sample. We must continue grinding until the imperfections are removed. The steel sample must be clear and reflective. To polish the sample we use alumina powder or diamond paste. The sample should be placed on the rotating disk after sticking diamond paste or alumina powder. To reveal the microstructure of the steel, we use diluted acid (2% Nital for steel) to etch. After etching, the sample must be washed with alcohol. The sample must be dried before examining the microstructure under a microscope. Five straight lines of the same length are drawn on the image of the microstructure printed on A4 paper, then count the grains cut by each line. After that, the total length of the lines is divided by the total number of grains. Then we can calculate the average grain size.Material and ApparatusA sample of steelGrinding and polishing machineOptical microscopeAlumina powder or diamond pasteAlcoholDilute acid (2% Nital for steel)Mounting resins WaterProcedureA sample of steel to examined was sawn The sample was ground It was polished using alumina powder or diamond paste, until it projected a mirror image. Then the specimen was etched in dilute acid (2% Nital for steel). After that, the etched section was washed with alcohol and allowed to dry. Then, the specimen was placed at the focus of the lens of an optical microscope and the microstructure was observed. The microscope image was printed on A4 paper. Five straight lines of the same length were drawn on the microstructure. Then, the grains covered by the lines were counted and added. Finally, the total line length was divided by the total number of grains and the average. grain size was calculated. Discussion The phases present in the observed microstructures are the grain and the grain boundaries. The above experiment observed the microstructure of steel. When we describe the structure of the material, we must considertwo main elements. These are the crystal structure and the microstructure. To describe the appearance of the material we use microstructure and to describe the average position of atoms in a unit cell we use crystal structure. Metals therefore have a crystalline structure, which is not normally visible. to the naked eye. When the metal melts and heats, millions of crystals begin to grow. Once the fusion is complete, the crystals cool and become large crystals. This large crystalline form of the material is called grains. In a crystal structure, there are millions of grains that have their own orientation and crystal structure. The areas between grains are called grain boundaries. Grain boundaries are the areas between grains. We can simply say that the interface between two grains is called grain boundary. In the crystal structure, grain boundaries are 2D defects. Low angle and high angle grain boundaries are the different types of grain boundaries. If the misorientation between two grains is less than 15 degrees, it is called a low-angle grain boundary. And also when the misorientation becomes greater than 15 degrees, it is called high angle grain boundary. The study of the structure of metal is known as metallography. Preparing samples for examination is an important part of metallography. To obtain correct observation and interpretation of the microstructure, the sample must be prepared appropriately. Sample selection, sectioning, grinding, polishing and etching consists of sample preparation. There are some important parameters in sample selection. This is the number, location and orientation of the sample examined. The surface of the sample should be smooth and have a mirror-like finish. So we need to do sectioning, grinding and polishing for this. We must be careful when preparing samples, as artifacts can lead to invalid interpretation of the microstructure. To reveal the microstructure, most materials are etched. Then, using an optical microscope, the specimens are examined. Metallography plays a very important role in examining the microstructure of steel. Quality control is the most important thing in metallography. Cutting metals causes some side effects. This will change the surface properties and deformed layers will be created on the surface. These deformed layers are different from the underlying metal. Metallographers apply techniques to remove these broken layers. Microstructural testing techniques are used in some areas. Some of them relate to routing quality control, fault analysis, and research. To determine whether structural parameters meet specific specifications, microstructural analysis is used. And it is also used in quality control. Due to various parameters such as heat treatment, composition or processing steps, changes in microstructures will occur. To determine these changes, microstructural analysis is used in research studies. Thanks to metallography, we can observe steel samples. In addition to determining the causes of failure of massive steel structures. Using metallography, we can identify the causes of failure of massive steel structures. Possible errors We must carry out the polishing process according to the required standards. Otherwise we will not be able to get the correct image easily and correctly. It is necessary to use a new specimen..