Grinding & Polishing

Grinding and polishing is the final stage in the metallographic sample preparation process and consists of several steps. Each step uses finer abrasive than the previous one, the ultimate goal being to produce a deformation-free, scratch-free and highly reflective sample surface. The sample may need to be examined, either etched or unetched, to reveal the microstructure of the material. It frequently happens that contrasts in the material are only visible after a successful etching step.

Extracted from: https://www.qatm.com/products/grinding-polishing-etching/

Grinding

The purpose of metal grinding and grinding of other materials is to remove the deformation and possible thermal damage introduced during sectioning and to prepare the samples for polishing.

When your samples have a rough surface or are clamped in a sample holder, you need a plane grinding step first. When preparing individual samples or samples by hand, you can go directly to fine grinding. The purpose of grinding is to reduce deformation and other types of damage introduced from cutting to a level that allows the sample to be polished. Fine grinding can be done in several steps using gradually finer grit sizes or in a single step on a modern rigid grinding disc.

Polishing

Metal polishing and polishing of other materials have to remove the deformations introduced during grinding and provide a highly reflective finish, so the samples can be examined on the microscope. Akasel polishing consumables are developed and optimised to provide the best result in the shortest time at an affordable cost.

The purpose of metallographic polishing is to assure that the true structure of the sample is made visible with a surface finish that will not disturb the examination in question. This is typically done in 2 or 3 steps  using suitable polishing cloths and gradually finer abrasives. These are selected depending on whether it is metal polishing or polishing of another material type.
 

 

Why do we need the polishing process in metallography process?

• Polishing is important process of sample preparation. Procedure can be divide 2 stage. First is Grinding (kind of Cutting), Second is Polishing(kind of gloss)
• These two stage conduct by various material’s property
• The scratch by Sectioning has to remove during the Grinding and Polishing
• Even Perfect sectioning make scratch on the specimen. So during the grinding, user have to remove scratch.
• Grind should be start from bold particle. Sand Paper Grit 150 and 180 is enough stage for remove scratch which occurred during abrasive cutting
• Sand Paper use for Grinding procedure.
• Recommended process include (180), 240, 320, 400, 600 Grit
• There are 3 units so Seller should be exact unit for customer

 

What is the basic procedure for polishing?

 

What is the common consumables used in polishing process?

For grinding:

 

For polishing:

 

Above sharing just for your reference. When you’re interested in investing a metallographic equipment to improve your quality process, select a supplier who offer a quality service and meet your specific needs.

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