Keywords: cleaning medium, Cotton wool, high-pressure air spray gun, household hair dryer, ultrasonic cleaning.

 The metallographic sample not only needs to be cleaned before inlaying, but also needs to be cleaned before changing the grinding and polishing particle size, that is, before entering the next process, to prevent large particle pollutants from being carried into the next process. The cleaning mentioned in this article mainly focuses on the metallographic samples after precision polishing. Of course, it can also be used in other stages of grinding and polishing.


1、 Main cleaning medium


In addition to clean water (tap water), distilled water and anhydrous alcohol (ethanol) are also common cleaning agents. These three cleaning media each have their own advantages and disadvantages. It can be used in combination with the field of view.


Clear water (tap water) is easy to obtain and convenient to use. It contains impurities, which can easily leave water stains, spots, and rust.


Although distilled water is stronger than clean water, it does not contain impurities and has a better cleaning effect. However, considering the usage environment, distilled water still has the possibility of rusting due to reaction with the sample.


Anhydrous alcohol (ethanol) does not contain impurities and has little potential to react with the sample. At the same time, the harm to human health is also relatively low. Relatively speaking, it is a better choice.


After cleaning, it is generally necessary to blow dry. Drying can be done using a household hair dryer or a high-pressure air spray gun. It should be noted that after the water dries up, spots will form on the surface of the sample, contaminating it. Therefore, it is recommended to use cold air to blow it away. Hot air is not conducive to water removal.


If the sample material is prone to react with water and rust, do not use water for cleaning or accelerate the cleaning speed. If the polishing agent on the surface of the sample is not easy to remove by cleaning, it needs to be scrubbed with Cotton wool.


2、 Use of cleaning media


After polishing the sample with low requirements, rinse it thoroughly with clean water (tap water), and then rinse off the water with anhydrous ethanol. Blow dry.


Of course, you can directly rinse the surface of the sample with anhydrous ethanol without using water. In this way, the easy volatilization of anhydrous ethanol can be utilized to prevent the cleaning agent from drying up on the surface of the sample and contaminating it. This method has a wide range of applications and can meet very high cleaning requirements. If there are contaminants on the surface of the sample that are not easy to wash, wipe the metallographic sample with Cotton wool dipped in absolute ethanol.


3、 Selection of cleaning equipment


After polishing the sample, clean it preliminarily with absolute alcohol, put it into the Ultrasonic cleaning, soak it in absolute alcohol or ultrasonic cleaner, and clean it with ultrasonic. Then blow dry.


Attention! After ultrasonic cleaning, it is necessary to rinse again with anhydrous ethanol.


This method can meet high requirements for sample preparation. Compared to simple mechanical cleaning, the cleaning effect is better. More capable of meeting high sample preparation standards.


If you have any other questions related to metallographic sample preparation, please log in to the official website www.qmaxis.cn for technical exchange with Kemai's engineers, or visit Kemai Testing Nanjing Laboratory for on-site testing.