Why prepare a metallographic specimen?
Preparation exposes a surface for examining material structure, defects, coatings and interfaces. It supports incoming inspection, process evaluation, failure analysis and research. Preparation artifacts must be distinguished from features of the material.
A seven-stage workflow
Define the objective
Identify the structure, defect, interface or hardness profile to examine. Record specimen identity, condition and orientation.
Sample and section
Retain a representative region and the target plane. Select a cutting route compatible with material and size.
Mount and support
Evaluate mounting for small, irregular or edge-sensitive specimens. Check heat and pressure compatibility.
Grind progressively
Remove preceding damage while preserving the target plane. Clean specimens and tools between stages.
Polish and inspect
Check scratches, smearing, relief, pull-out and edge rounding. A shiny surface alone does not establish preparation quality.
Observe for the stated purpose
Some defects and coatings need examination before etching. Etching is selected for the material and is not always required.
Record and review
Link images and measurements to specimen location, equipment, actual settings and method version.
Adapt the route to the task
Heat-treated metals, electronic packages, ceramics and composites require different preparation choices. Confirm a method for the specimen instead of reusing one fixed recipe.
Source reference www.cnnoet.com ↗ · Compiled from public references; see the source link