1.Why the metallographic examination is done for a material.

2. Write and explain the steps used for the Metallographic Examination of a sample.

3. Why should the specimen be roughly washed after each stage during either grinding or polishing?

4. What is the purpose of etching metallographic samples?

5. Why is important to calculate the average grain size of a material

6. Calculate the average grain size and ASTM grain size number of the material by using the picture of microscopic investigation which is assigned to you