Metallurgical Sectioning

The objective of the abrasive cutter technique is the reveal a feature of the component or reduce the size of a sample to size which can be accomodated for metallurgical polishing.

The key components of the abrasive cutter are

• Safety
• Secure vices
• Coolant
• Wheel feed
• Wheel selection

It is important to have a safe working envoiroment to ensure no injury to the operator. It is recommended that abrasive cut off machines be used with a locked hood. Abrasive cut off machine rotating at speed of 3000 rpm represent a danger to the operator, so adequate safety prcautions must be engineered into the machine.

Various method of holding samples can be utilised, it is important that the piece to be sectioned is secure, movement of the sample will effect the quality of the cut with regard to planarity and also lead to wheel breakage. Cam lock vices are standard features on abrasive cut off machines and can be very versitile. More bespoke fixturing can be installed for specific applications.

The use of a coolant is used with a soluable additive to ensure the coolant is more effective. The addition of a 4% solution in water will also prevent rusting of parts. It is important to clean the working areas of the machine and recirculation tank to ensure effective supply of coolant during the cut.

Wheel feed again is a function of the machine design, it is always best to have minimum surface contact with the sample. It is best advised to cut londitudinally if possible to allow a small width / long cut operation to improve the cut quality.  Automatic operation gives a controlled feed to give the best cutting results, the addition of pulse cutting or oscilation motion of the wheel can also work very well for some components. When manual cutting it is advised to work with a pulse type feed, but it is important to apply the correct pressure to ensure wheel breakdown and efficent cutting of the sample. Applying too much pressure will increase wheel wear and also give the possibility of wheel movement and blade breakage.

The selection of the cutting wheel is very important to ensure economical cutting of samples. The abrasive wheels used in the metallurgical laboratory are resin bonded wheel with grain of alumina or silicon carbide. The resin type is selected to give the wheel a hardness - wheel wear indication and the grit is selected to be more approiate to the type of material to be cut, generally ferrous or non ferrous.

Spectrographic are able to offer guidance for your cutting machine selection with the correct vices and abrasive cutting wheel to suit your application.