strathSEEA

Sectioning is the process of cutting a larger bulk sample down to a required size which is suitable for both mounting and analysis. Typical sectioning techniques such as shearing tend to result in cold work which can modify the sample’s microstructure, which can lead to spoiled results during the analysis process. Therefore an abrasive technique using a cut-off wheel was selected for the sectioning of the samples.

 

The initial, uncarburised samples had already been cut prior to the consummation of the research, so only the carburised treated samples required sectioning. Depending on the material being used, a different grade (hardness) of abrasive bond on the wheel is used. Generally the softer the sample, the harder the abrasive wheel used. Even with the increased hardness associated with the expanded austenite zone, a standard grade of abrasive wheel could be used for the initial cut of the carburised samples.

 

The initial cut was of a surface area approximately 20mm x 50mm and a depth of approximately 3mm.

 

During the finer cutting process the size of the carburized samples were kept as close to the size of the initial samples as possible, this being approximately 20mm x 10mm, with the strip being further divided into 3 smaller samples. The parameters for the finer cutting machine were as follows:

 

• Velocity of cut-off wheel                      -       2000RPM

• Force applied by cutting wheel          -       1.5N – 2.0N

 

Between the two sectioning stages and after the finer stage, the sample cleaned using ethanol.