In order to correctly study the characteristics of a metal, it is important to understand its atomic and the physical structure. This branch of study is termed as metallography which deals with the analysis of the physical structure of the metal piece. All this is studied under a microscope through a sample of the material which helps in examining the atomic and chemical structure of the constituents. But the most important thing is the sample preparation for the analysis.
Before the Metallographic Analysis, the sample must be prepared following the correct procedure. Let us quickly rush through the process:
- Sectioning and cutting: For easier handling, the sample needs to be properly sectioned. The method might differ depending on the material like abrasive cutting for metals, diamond wafer cutting for ceramics and thin sectioning for plastics. These help in preventing the damage to the microstructure of the material.
- Mounting and planar grinding: The mounting process involves improving the handling of irregularly shaped samples. Among different options, compression mounting is used for metals, castable mounting resins for ceramics and electronics. The planar grinding process involves reducing the size of the sample and preparing for polishing. It should be done with high precision to not produce greater damage to the sample.
- Polishing: As the name suggests, it focuses on removing surface damage. It can be done in two phases including rough and final polishing if needed to get the required surface for a better analysis.
After this, the chemical etching process is used to optically enhance the features of the material. But apart from the chemical process, other techniques are also brought into use including thermal, electrolytic, plasma and others. This is the process conducted before Metallographic Analysis and must be followed for better and correct analysis.
