Have you ever encountered cracking defects when preparing samples using a hot pressed metallographic inlay mechanism? And there is more than one situation, such as central cracking, circumferential cracking, and expansion cracking, When encountering this situation, does it raise a question, is the cracking of the embedded sample caused by the metallographic inlay machine? Before figuring out the reason, don't let the metallographic inlay machine take the blame. Let's explore together what's going on!

The application engineer of pulse detection has provided suggestions on the causes and solutions of several common inlay cracking defects. The editor summarizes and organizes them as follows:

Center cracking


Reason for occurrence: It is due to the sample size being too large relative to the shaping cavity and having sharp corners. When placed in the shaping cavity, the space is too limited and narrow, leading to cracking during shaping.


Solution: Reduce the size of the sample appropriately to leave more space for the addition of inlay material relative to the shaping cavity, effectively avoiding inlay expansion and cracking defects. If the technical requirements for sample size cannot be reduced, and conditions are met, it can be considered to increase the size of the shaping cavity, such as replacing large-sized inlay tubes.


Circumferential cracking


Reason for occurrence: It may be due to moisture mixing in the inlay material, or it may be due to air mixing during the inlay setting process.


Solution: Preheat the inlay powder or preform the inlay powder before proceeding with inlay. When the inlay material is in a liquid state, the pressure is instantly released. This can effectively avoid the occurrence of circumferential cracking defects.


L Bulging and cracking


Reason for occurrence: It is caused by a short curing time or insufficient pressure during inlay.


Solution: Properly extend the curing time, increase the pressure from the liquid state of the inlay to the curing molding period, and these measures can effectively avoid the occurrence of expansion cracks.

When encountering the problem of cracking in the embedded sample again, based on the situations organized by the editor, compare and analyze the reasons, and take appropriate methods to try to solve it. The cracking of the embedded sample is not necessarily caused by the metallographic inlay machine! If the above methods still cannot solve your similar problem, a pulse detection application engineer can help you. You can contact us for consultation at any time. It's really free of charge, ha!