Metallographic sample preparation process, whether it is metal or composite materials, electronic materials, etc., the use of metallographic sandpaper is basically the first process of sample preparation, the purpose is to remove the damage caused by the cutting process and deformation of the layer, which belongs to the coarse grinding process, in order to prepare for the subsequent polishing, so this process is a rather critical step, if not dealt with properly will affect the effect of the subsequent process, or even lead to the test sample grinding can not If not handled properly, it will affect the results of the subsequent processes, or even lead to the failure of sample grinding and the inability to carry out the final metallographic analysis. In view of this, Chain metallographic editor has a few suggestions to share with friends, I believe it can bring help to your sampling work.
Recommendation 1: Replace the metallographic abrasive paper in time.
The grinding particles of the new metallographic paper are sharp and pointed; while the corners of the grinding particles of the old metallographic paper are worn away and broken, and the grinding particles are completely buried in the adhesive layer. At this time, the grinding ability of the metallographic paper is poor, the removal rate is low, and the chance of rubbing the paper base is increased, the surface of the ground sample is shown in the following comparison.
In the old and new sandpaper abrasions, the abrasions on the right are clearer, with one abrasion overlapping the other, showing a three-dimensional image. On the other hand, the abrasion marks on the left side of the old sandpaper do not have a clear three-dimensional shape, and appear to be on a flat and smooth surface. Does the left image look better? Wrong! Because in this case, the depth of the deformation layer on the surface of the sample will be doubled, only because the abrasion marks are flattened, so the surface of the sample is more reflective, creating an illusion of more successful preparation to you. Therefore, remember to replace the metallographic sandpaper as soon as it is used up, don’t be reluctant to do so!
Suggestion 2: Rinse the sample thoroughly.
After grinding each label of metallographic sandpaper, the samples should be thoroughly rinsed, this step should never be omitted, in order to avoid cross-contamination. Otherwise, the larger grinding particles left in the previous process will make the sample surface scratches more, deeper and not easy to remove, and sometimes even the more grinding the more serious situation. I have personally experienced, there is no choice but to make samples again. Therefore, please remember to rinse the sample and the abrasive disc thoroughly before changing to a different standard of metallographic abrasive paper.
Recommendation 3: Avoid embedding abrasive particles
When preparing softer, low melting point metals with metallographic sandpaper, embedding of small grinding particles is a common occurrence. This can be avoided by applying paraffin wax or candle wax to the surface of the metallographic sandpaper prior to grinding and then proceeding to normal grinding. Of course, you need to be careful not to apply too thick a layer of wax. Otherwise, the removal rate of the paper will be significantly reduced. Just apply a little bit gently, and you will get the hang of it after a few tries.
Of course, to avoid embedding can also use polishing paste instead of metallographic sandpaper, or the use of diamond grinding disk can also be used, these methods whether to use mainly depends on the material being prepared samples and the purpose of the experiment, which you can flexibly
The above are a few suggestions shared by the editor of HONWAY, I believe that when you use the metallographic sandpaper to grind and polish, these suggestions are enough for you to grind the specimen into the desired model!
If you encounter a problem that cannot be solved by the above suggestions, you are welcome to contact HONWAY’s engineers, whose professional advice will surely help you to cope with it easily. There is always a solution to any problem, we will face it together with you and explore it together.
