The Metalogram is our way of creating generic methods based on the two parameters, ductility and hardness.
The selection of a preparation method in the Metalogram depends on these two properties:
Description of the Metalogram
- Hardness: the easiest attribute to measure but is not sufficient information about a material to find the correct preparation method.
- Ductility: the ability of a material to deform plastically and is far more important. How does a material actually respond to mechanical abrasion? Is it easily deformed, or do we get cracks and pull-outs during preparation?
The x-axis represents the hardness in Vickers. The values are not shown in a linear way because the variety of preparation methods for softer materials is greater than for hard ones. The shape of the Metalogram results from soft materials generally being more ductile and hard materials usually being more brittle. ”
How to use the Metalogram
First, find the hardness on the x-axis. Then, depending on the material's ductility, either move up or down. Unlike hardness, ductility is not easily defined in precise numbers. Materials must be placed on the y-axis according to your own previous experience. You must have an idea of how a material will perform, that is, whether it is ductile or brittle.
When you have done your selection, just click on the Metalogram. Sometimes you will have to choose an option ex. “Diapro” or “Susp. P/Lub”
Make your selection and then the appropriate method will be shown inclusive all parameters as well as the consumables needed.
The seven methods, A - G, cover the complete range of materials and they are designed to produce specimens with the best possible results.
The three methods X, Y and Z are designed to be shorter creating quick acceptable results.
For the preparation of materials which cannot be placed easily in the Metalogram, for example composites, coatings or other materials consisting of various phases or components, the following rules can be applied:
- Select a method which is suited for the material's predominant component.
- Check the samples after each step and, if preparation artifacts do occur, adjust accordingly
If you would like more detailed guidance preparing ex. complex materials visit www.struers.com
, go to “Knowledge”, select ”Metalog Guide”. Here you will find tips, tricks and “Best Practices” to help you get even more successful creating the perfect preparations.