4 Steps For Successful Metallographic Sample Preparation

A metallographic analysis can be beneficial when trying to determine the chemical makeup and hardness of a particular sample.

Preparation is an essential part of the sampling process. It's critical that you understand how to prepare your samples properly in order to ensure the accuracy of your test results.

Poor preparation habits can inadvertently create materials that will contaminate your sample. Follow these four steps for successful metallographic sample preparation in the future.

1. Sectioning

Modern technology has made it possible to collect accurate data from a small sample material. This means that you don't have to test a bulky piece of metal when conducting your metallographic testing.

Sectioning allows you to separate a smaller representative sample from the larger piece so that you can expose the material that needs to be analyzed without having to make accommodations for bulky equipment.

2. Mounting

Once you have sectioned off a sample piece, this piece must be secured to a mounting material in preparation for testing. It's essential that you use the right mounting material for the type of metal you are planning to test.

You want your mounting material to grind away at the same rate as your sample material. Be sure that you are using the right time, temperature, and pressure levels when mounting your sample.

3. Grinding

Proper mounting ensures that your sample material will be able to withstand repeated grinding. In order to accurately test the sample, both the sample and the mounting material must be ground down to create a flat and even surface.

You must use a flushing medium to continually eliminate any residue left behind by the mounting material as the grinding process occurs. Once you have created a uniform surface, you can move on to the polishing phase of your sample preparation.

4. Polishing

Grinding can create some deep grooves and scratches on the surface of your sample material. Polishing allows you to eliminate these imperfections to create a smooth and shiny test surface.

It is critical that you spend the time necessary to give your metallographic samples the polish they need. Only thorough polishing ensures that the defects visible in the sample are indicative of actual flaws in the material and not just damage left behind from the grinding process.

The accuracy of your metallographic testing results depends on the preparation of your sample materials. Invest time in sectioning, mounting, grinding, and polishing to improve your metallographic testing in the future.

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