Question

Explain the need of washing and drying of metallography samples before proceeding from one grinding or polishing operation to the next?

Answer 1

hello dear. here is your answer



The surface of the specimen is first made flat by an abrasive belt or rotary disc machine. These machines are frequently equipped with coolant attachments to ensure cool cutting and to help wash abraded particles from the belt or disc. Care should be taken to prevent overheating of the specimen during the rough grinding stage.



hope it will help you


please mark it as brainliest

Answer 2

Grinding of Specimens

The surface of the specimen is first made flat by an abrasive belt or rotary disc machine. These machines are frequently equipped with coolant attachments to ensure cool cutting and to help wash abraded particles from the belt or disc. Care should be taken to prevent overheating of the specimen during the rough grinding stage.

Abrasive belts or discs for wet grinding usually employ Silicon Carbide as the cutting media. Kemet Met Discs are plain backed and Bramet are Self Adhesive. Abrasive grit size is usually in the 120 - 320 range for rough grinding. Rough grinding produces a flat, plane surface and removes harmful effects resulting from cutting-off operations. It is advisable during the rough grinding operation to bevel the sharp edges of the specimen, or specimen mount to prevent tearing of grinding papers and polishing cloths during subsequent operations. Excessive pressure during rough grinding will form deep scratches, and will increase the depth of disturbed metal on the surface of the specimen. This disturbed layer may extend from ten to fifty times the depth of the scratch produced by an abrasive grain