Diamond wafering blades used on Precision Cutting machines, such as the Isomet High Speed, are an excellent way to make extremely low damage sections in your metallographic samples. But do you know how to look after your blades?
After a number of uses a diamond blade may start to cut less efficiently. Cut quality decreases and cut times increase. This is caused either by the diamond at the surface wearing/getting blunt or by the surface becoming blocked with debris. When this happens, the blade drags through the material rather than cutting effectively. This may result in excessive specimen damage. Dressing the blade removes debris from the blade as well as exposing fresh diamond abrasive. This is done by cutting into a dressing stick.
For the IsoMet Low Speed and Isomet 1000, manual dressing attachments are used. For the Isomet High Speed, an automated system is available. Not only does this make the process easier and more consistent, you can also dress automatically while cutting. This function is vital to achieve the highest quality and speed of sectioning, especially for tough materials.
If you are using Buehler Series 15, Series 20 or CBN blades use a green silicon carbide stick (11-1190). Use the alumina dressing stick (11-1290) for Series 5 and Series 10. Usually one or two dressing cuts are enough to bring the blade back up to optimum performance. It is recommended to dress at lower rpms (150-500 rpm) and moderate cutting speed (it should take around 40 seconds to cut through the dressing stick). If you find yourself dressing often the blade might not be appropriate for your material.
The table recommends which blade to use with which material. Remember that all blades (except 30HC, for which no dressing is required) should be dressed 6-8 times before first use.