In this issue, the editor mainly discusses the experience of using domestically produced metallographic consumables based on their own usage experience. Domestic consumables have made rapid progress in recent years, and this article only represents the personal views of the editor.


1、 Metallographic sandpaper


Domestic sandpaper has a significant price advantage compared to imported sandpaper. During the use process, the editor found that domestic sandpaper, especially domestic low-grade metallographic sandpaper, is prone to the following problems:


1. Curling, water curling


Domestic sandpaper curling and water curling are small problems, but in fact, paper has this type of problem when encountering water. To be honest, imported sandpaper also curls when encountering water. But domestic sandpaper curls too much, especially when cut into circles. This should have been a minor issue, but for users, it is very inconvenient. It is difficult to smooth it out, and sandpaper cannot fit the working turntable or glass plate, which is very unfavorable for grinding and polishing the sample. It is really a small problem and a big trouble. Of course, there is an industry historical issue here: many domestic polishing machines have a smaller diameter of the rotary table than imported polishing machines of the same period, which also exacerbates the curling problem.


2. Damaged by water


If sandpaper curls up in water, it can still be considered a small problem, and sandpaper that is damaged in water can only be considered unqualified. Although it is not specified that water must be added to the metallographic sample during the coarse grinding stage, each step of the sample should be washed clean (it can be chosen to blow dry each time). Users usually use water to cool down during rough grinding, to prevent overheating while also taking away debris from the grinding process. Not to mention that some metallographic workers wet the back of the sandpaper, which can better fit the sandpaper onto the work turntable or glass plate. Sandpaper that is damaged by water lacks both universality and applicability.


3. Wear particles are prone to detachment


The easy detachment of abrasive particles is mainly reflected in domestic low-grade sandpaper, which has two direct impacts: one is that the sandpaper quickly loses its grinding effect, and the other is that there are large scratches on the grinding surface of the metallographic sample.


Sandpaper with easily detached abrasive particles is very troublesome to use, with more frequent replacement times, which reduces its price advantage.


Another issue brought about by abrasive shedding is&flash& Flash; Scratches and detached abrasive particles can easily scratch the surface of the sample.


It is very interesting that the above problems are not easy to occur on domestic high-quality sandpaper, possibly due to:


High count sandpaper is thinner, less prone to bending, but easier to smooth;


High grade sandpaper is more high-end, valued, and uses better materials;


High grade sandpaper has small abrasive particles and its own grinding force is small. The changes in grinding force are not obvious, and the scratches caused by the detached abrasive particles are not easily noticeable.

The number of imported sandpaper is generally as high as 1200 (European standard)/P4000 (American standard), and its polishing effect is similar to that of using a 1 micron diamond polishing agent for polishing. Domestically produced metallographic sandpaper sometimes provides particularly high grade sandpaper, which has a stronger overall performance compared to domestically produced low grade sandpaper and is closer to imported similar products.


2、 Polishing agent


1. Single particle size


The commonly used polishing agents in China are needle and tube polishing paste and canned polishing spray. Of course, polishing powders and liquids are also common, but these polishing agents are generally only available at the 0.5 micron level.


It is not that domestic polishing agents do not have smaller particle sizes, nor is it that domestic consumables cannot achieve finer particles. This is entirely due to usage habits, as metallographic workers often mainly learn metallographic knowledge and lack contact with information such as consumable specifications.


Because of this, domestic consumables sellers also tend to provide polishing agents in the 0.5 micron and 1 micron levels. Because this size level of polishing agent has a wide coverage range, is basically suitable for various materials and magnification, and the price is not too high.


However, the magnification of current metallographic microscopes has reached 1000 times, and polishing agents at the 0.5 micron level are only barely sufficient.


2. Single type


The reason for the current situation is also related to the development of the industry.


On the one hand, domestic manufacturers of metallographic equipment and consumables do not provide metallographic sample preparation plans. And the sample preparation plan often contains these critical and valuable information.


On the other hand, although manufacturers of imported metallographic equipment and consumables provide preparation plans, they often do not do localization and do not speak English when opened. They also use their own product number information, and cannot directly obtain particle size and polishing agent type information.


In the field of polishing agents, there are more types and particle sizes available for imported polishing agents. This is an advantage of imported products.


3、 Metallographic polishing cloth


1. Shedding hair


The personal experience of using domestic polishing cloth is quite good, but there are good ones and bad ones. Some polishing cloth fibers are too easy to fall off, and the sample and fingers are stained with the fallen fibers. It is difficult to imagine that this is a polishing cloth that can be used normally.


2. Inconvenient use of polishing cloth


Like similar imported products, domestic polishing cloths also commonly use adhesive backing. However, some polishing cloths cannot be completely removed with adhesive backing, instead sticking to the rotary table, which requires an additional process even if it is effortless to clean.

And for imported similar products, either the back glue can be completely removed; Either use it with a replaceable iron plate while the adhesive can be completely removed; Imported metallographic polishing cloth and products without adhesive backing, using magnetic backing, are easy to use, replace, and remove.


3. Durability


The durability of domestic polishing cloth is not as good as that of imported similar products. Imported polishing cloths often have a record of being used for 6 to 12 months, and even have established maintenance standards for polishing cloths in use.


The issue with the durability of domestic polishing cloth may be due to the lack of a grinding disc replacement system. Inconvenient maintenance and prolonged exposure to moisture.


Conclusion: Domestic metallographic consumables need to further enhance their reputation, compete with imported products, and gain recognition from all parties. Further efforts are needed.


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