Process of Microstructure Testing and Analysis Laboratory to Study Test Sample
With the help of a Microstructure Testing And Analysis Laboratory, an expert can examine the material’s microstructure and provide information. This again helps to determine whether the structural parameters are within certain specifications or not.
With the help of the result published in the analysis, the expert can verify the material is within the criterion and accept or reject the material.
The size or the amount of the features in the element can be quantified, and it can be compared to acceptance criteria. With the help of these examinations, one can often conduct the failure analysis and help identify the type of material in question.
It will also help in determining if the material has received the proper processing treatment as per the procedure. While conducting the Microstructure Testing And Analysis Laboratory will evaluate the following:
- The extent of carburization and decarburization, intergranular attack, corrosion, and grain size.
- Depth of alpha case, especially in titanium alloys
- Percent Spheroidization
- Inclusion ratings
- The volume fraction of various stages or second stage particles in metals
To conduct the analysis to identify and evaluate the microstructure of a material, it is essential to prepare a sample piece carefully and properly. The steps that are included in preparing the sample are as follows:
- Selecting the representative samples of the material used in preparing the finished product.
- The test sample is selected so that it doesn’t alter or destroys the integrity of the final product’s structure.
- The section is then mounted without causing any damage to the test sample
- Grinding is done to achieve a flat sample with a minimum amount of damage to the surface of the sample.
- The mounted sample needs to be polished and grounded.
- For the proper revelation of the structure, etching needs to be done properly.
Below stepwise process is explained of how conducting Microstructure Testing And Analysis Laboratory:
the representative test sample is essential for proper characterization of the microstructure or feature of interest, making it a very important first step. For instance, grain size measurement is conducted on the traverse section, whereas the micro structural evaluation is conducted on the longitudinal section.
Hence it is important to notify the lab with information about the rolling direction or the orientation of the test specimen.
the test sample needs to be carefully sectioned so as to avoid alteration or destruction of the material structure. For instance, if an abrasive saw is used, it is essential to keep the sample cool with the help of a coolant or lubricant so that it doesn’t burn or get overheated.
However, how much ever care is taken while abrasive sawing or the electric discharge machining is performed, a slight distortion will occur on the sample surface. During the subsequent steps, the deformation needs to be taken out for proper analysis.
once the test sample is sectioned to the right size, it is mounted on the plastic or epoxy material to enable the processing and the polishing and grinding process.
The mounting medium should be compatible with the sample with respect to hardness and abrasion resistance. Many times, the mounting material is thermosetting phenolics like bakelite and thermoplastic materials like lucite. This process involves putting the sample on a mold and surrounding it with suitable powder.
When the mold or the fit is heated and pressurized at the correct levels curing or setting of the media occurs. The mounted sample is then removed from the mold. If the use of pressure or heat might alter the structure of the sample of interest, then castable cold mounting products such as epoxies are used.
this step is followed up after mounting to remove the damage on the surface that occurred during the sectioning and provide a flat-surfaced sample for testing.
Generally, water or lubricated abrasive wheels are used during this process or a series of progressively finer abrasive grits. This procedure ensures a flat surface that is nearly free of the deformed or disturbed metal that was introduced by the previous sample preparation process.
this step removes the last thin layer of the deformed surface from the metal. It provides a properly prepared sample ready for examination with an unetched characterization like inclusion content or any kind of porosity that may exist.
this is the final step in the entire process to showcase the microstructure of the test sample. This step will reveal the features like grain boundaries, second stage particles which were not seen in the unetched sample.
By following the process as mentioned above, a meticulously Microstructure Testing And Analysis Laboratory will provide the quantitative results to all the parties involved in manufacturing the final product. This report will render a quantitative result that will help determine the product’s reliability and durability.