The Struers Preparation Philosophy & Knowledge
Struers has been at the forefront of material preparation and analysis innovation for over 75 years, building up decades of expertise. As knowledge leaders, we view it as our responsibility to share scientific insights and practical expertise that help you to acquire the skills you need to achieve excellence.
This starts with the considerations that go into our preparation philosophy. The aim of materialographic specimen preparation is to reveal the true structure of the specimen, whether it is metal, ceramic, sintered carbide, composite or any other solid material. The easiest way to accomplish this is to use a systematic preparation method. When our work routinely involves examining the same material in the same condition, we want to achieve the same result each time for reproducibility.
The Four Criteria of Our Philosophy
1. Systematic Preparation
Our philosophy starts with systematic preparation approach based on material properties. Different materials with corresponding properties (hardness and ductility) respond similarly and require the same consumables during preparation. We look at our consumables from a scientific perspective to define their performance and thus determine their best application. Our Struers Metalogram organizes materials by their properties and recommends methods.
2. Reproducibility
Once a preparation method has been developed and adjusted, it should produce exactly the same results for the same material every time the method is applied. This requires consumables of a high standard and uniform quality and control of the preparation parameters, many of which can only be adjusted and controlled by (semi) automatic equipment.
3. True Structure
Theoretically, we are interested in examining a specimen surface that shows us a precise image of the structure we are going to analyze. Mechanical preparation, however, makes it almost impossible to achieve all of the above-mentioned conditions. There will be slight damage to the structure, but this damage cannot be seen using an optical microscope. The damage does not influence the examination results. This nearly perfect condition, to which any damage is only superficial, is commonly called the true structure.
4. Acceptable Preparation Results
It is only necessary in a few cases to obtain the true structure. For most examinations, a few scratches or slightly rounded edges will not matter. For cost-efficient preparation, the finished surface only must be as good as needed for a particular analysis. Preparation time, operator time and the amount of consumables used for the total preparation process are important factors. The cheapest consumables do not always give the lowest price per specimen.
Preparation Process
The preparation process is divided into several steps that must be executed correctly and systematically to ensure satisfactory and reproducible results. Dive into each module below for our practical expertise on each step:
Materials - What are you working with?
Every material is different. The materialographic process you choose depends on the material, as well as the application and purpose. Whatever you are working with, from metals and alloys to spray coatings and microelectronics, our material application notes cover all you need to select and accurately perform the ideal preparation process for each material.
Metalogram - Which method is optimal?
The Struers Metalogram is a metallographic preparation guide to help users select the optimal sample preparation methods for a wide range of materials, metals, alloys, and ceramics. Used worldwide as a trusted reference for metallographic sample preparation and metallography preparation, it classifies materials according to their hardness and ductility, making it easier to identify the most effective material preparation method.
Cutting - How do I account for variables to achieve the cut I need?
Materialographic sectioning is where most microstructure analysis begins. Minimizing cutting artifacts will help the remaining materialographic process and act as a good base for efficient and high quality preparation. Gain a good understanding of the abrasive cutting process to select suitable clamping and cutting methods.
Mounting - Which method and resin should I use?
Materialographic mounting is a helping process assisting the mechanical preparation process as well as the final test. These processes are key to having specimens that are easy to handle and clean, and give a good image of a coating or an edge. Learn to evaluate the need for mounting, select the appropriate method, and understand the different characteristics of mounting resins.
Grinding and Polishing - Which combination of steps should I follow?
Grinding and polishing is the key process in materialographic sample preparation, with a large variety of processes in responses to mechanical impact, process parameters, abrasives, and surfaces, representing the total complexity of the step-by-step production of a reflective and deformation free surface. Learn to choose the correct method, including abrasives, surfaces, and other tools, and troubleshoot issues to achieve the results you need.
Electrolytic Preparation - Which settings should I select?
For homogeneous metals, electrochemical processes can remove material from a specimen and thereby substitute or supplement mechanical preparation. Empirically based reference methods are published in literature, and used as starting point for selecting suitable electrolytes and electrochemical parameters. Learn how to select the appropriate method and application settings, and troubleshoot issues.
Etching - Which etchant is right for my sample?
A reflective surface does, in many cases, not reveal the information of interest at microscopic examination. Etching is a method for creating contrast and can be done with different techniques. Get an introduction to etching and guidance on method selection.
Verification Process
Verification confirms that materialographic preparation and analysis are performed correctly and meet defined standards.
Hardness Testing - Which test should I use, and how do I ensure accuracy?
Fast, robust, and well-proven test methods for materials verification are necessary. Vickers, Knoop, Rockwell, and Brinell methods, with a countless number of loads and indenter geometries, give an almost countless number of procedures, suitable for simple characterization of a large fraction of existing materials. Get introduced to the common methods, and learn how to choose an appropriate method, ensure accuracy in your tests, and address common problem scenarios.
Microscopy - When should I use the various methods and filters?
The last step in many materialographic processes is examination in microscope. The knowledge about materials structure, sample preparation, and microscopic techniques are combined in front of the microscope, which in many ways makes this field a specialist skill. Learn about the four main types of materialographic microscopy and some of the techniques used.
Image Analysis - What main process steps should I follow?
A microstructure can be described by a number expressing, for example, a classification or a threshold value of a well-defined material. Image analysis is used to automate this quantitative analysis by the use of software tools. Learn how to approach image analysis in a systematic way.
Weld Inspection - What challenges do I need to be aware of?
Welds are very often examined by many different techniques to evaluate geometric features, hardness value, as well as microstructure analysis. To reveal all relevant information on a welded sample, many conventional materialographic processes can be used, leaving only the geometric verification to a dedication solution. Get an overview of how to do weld inspection and the specific challenges that welds introduce for materialographic preparation.
Specialist Knowledge
Take advantage of our application specialists' expertise with guides for special applications, articles on the latest in materialographic research, or by reaching out directly.
Special Applications - How do I overcome unique challenges and requirement?
Designing dedicated products and processes for single applications is especially useful when requirements are unique, or a widespread use justifies a special solution. Get our practical expertise guidance on the processes and challenges of miniature electronic components, constructions that have to remain intact after inspection, mineralogical samples, and samples for transmission electron microscopy.
Materialographic Articles - What are the latest developments in metalography?
Explore the latest materialographic research, findings and methodology in our in-depth materialographic articles, prepared by Struers’ application specialists using insight and information from around the materialographic world.
Application Specialists - What do experts recommend for my specific needs?
A group of 27 Struers specialists are dedicated to helping businesses by developing, using, and verifying materialographic skills and theories. With backgrounds from quality labs, production, R&D, and education, the specialists represent a variety of experience and skills reflecting the customers we support.