Sectioning, the preparation of metallic specimens for mounting, polishing and testing. This is required in most metallographic work. It enables the production of a sample piece that is suitable for testing and analysis purposes. This allows the test piece to be properly oberserved, documented & measured.
Care must be taken during the sectioning process in order to obtain the highest quality polished surfaces possible. The finished material can often be affected by different factors. These different factors range from alloy composition to processing conditions such as; cold working, heat treatment, and welding.
In most cases sectioning is required to get an appropriate size and shape for testing purposes. Different sectioning techniques can be used. It is important that the sectioning technique selected must not significantly alter the material characteristics.
Some damage will inevitably occur at the cutting site. However, this damage can be minimized by applying appropriate techniques and taking care in the sectioning process.
Fracturing can be used to obtain samples from brittle materials such as ceramics and carbides. This process requires fracturing the test piece and then polishing the fractured test piece.
Shearing is a sectioning process that generates little heat, but it does produce substantial deformations and is not recommended for sensitive materials.
Sawing does produce a rough surface, considerable heat, and deformation.
abrasive cutting for metallography is the most common method and most highly considered method, this is due to the wide range of materials and hardnesses which can be effectively cut, and the excellent quality of surfaces produced.
This method is popular in the electronics industry however the cutting rates are very low.
The quality of the abrasive cutting wheels. Always the most important feature to consider in selecting abrasive cutting wheels is safety.
Only purchase abrasive cutting wheels from reputable manufacturers.
To ensure the best abrasive cutting for metallography it is important to match the work piece material to the abrasive cutting wheel.
This is done through matching the wheel to:
The material being cut and the hardness of the material impact on the choice of abrasive material to be used in the cutting wheel.
Finer abrasive grains create a smoother cut and are preferential for delicate work. The thinner the abrasive cutting wheel the less damage to the work piece that occurs.
Abrasive cutting wheels can use either rubber or resin for bonding:
Softer wheels have a more porous bond which permits the wheel to break down and be consumed at a faster rate. The faster breakdown allows for more of the cutting particles to be exposed. This increases the cutting process.
Softer wheels are designed to cut hard metallic materials.
Harder wheels have a less porous bond and breakdown at a slower rate. They are designed for cutting softer metallic materials and as such provide an optimum cut for softer materials.
Sectioning is required in most metallographic work. Sectioning using abrasive cutting wheels enables the production of a sample piece that is suitable for testing and analysis. Care must be taken during the sectioning process to obtain high quality polished surfaces.
Most issues that arise in material testing can be traced back to improper care being taken when selecting and preparing a test specimen.
If you have any questions use the button below to contact us directly. Or learn more by visiting our precision cutting page
Yes, we manuafcture a wide range of different sizes and specifications of abrasive cutting wheels. Send us in your requirements and we will let you know how we can help
Rubber bonded cutting wheels are best suited for cutting with a coolant. åtto also provides a range of rubber bonded cutting wheels suitable for dry cutting. Please specify if you require cutting wheels to operate without a coolant by email: email@example.com
What coolant is recommended for Rubber Bonded cutting wheels? Rubber bonded cutting wheels are suitable for use with water and 3% soluble rust inhibitor added. Oil based coolants are not recommended.
For a more extensive education of metallographic techniques, you could refer to Samuels, L.E., Metallographic Polishing by Mechanical Methods, American society for Metals 3rd edition.
Cutting speeds for abrasive cutting wheels vary according to section size and the material being cut. For questions relating to operating speedm you can email us at : firstname.lastname@example.org
What is the maximum operating speed for rubber cutting wheels?Always check the speed specified with the wheels before use. Most rubber bonded cutting wheels are rated to 60 m/sec but special bonds are available for higher speeds.
åtto abrasives Ltd will use all reasonable measures to ensure that the contents of this Site are accurate and up to date and does not accept any liability for any information which may not be accurate. We also reserve the right to change data, references and product specifications at any time.
Price and availability information is subject to change without notice.
Note 1.1. This article does not purport to address all of the safety concerns, associated with the preparation of Metallographic specimens or the use of abrasive cutting. It is the responsibility of the individual and their company to establish appropriate safety and health practices.
Dealing with abrasives and metallic materials is always dangerous and appropriate care should be taken. Never use abrasive cutting wheels on an unguarded cutting machine.