WWW.07MET.TK 1. What’s the goal of metallography specimen preparation and examination? 2. 400 grit SiC paper and 1000 grit SiC paper, which one is for coarse grinding, and which for find grinding? 3. The ability to prepare a specimen is an art. Name two things that need to be taken care of in order to get a mirror-like surface free of scratches. 4. What’s the purpose of etching? 5. Suppose a grain size is about 50 micrometer. What’s the grain size in the image of 100X microscope? 6. What are the functions of the objective of a metallurgical microscope? 7. The optical micrograph shows microstructure of a piece of polished and etched molybdenum. Why might an ASTM grain size not adequately describe the size of the grains in this material?
8- Draw a diagram for a fixed proportion of each phase in a two phase specimen (ex. 25% A, 75% B)? And describe how does the number of individual particles of the minority phase (the one with the smaller amount) vary with particle size? 9- For a fixed proportion of each phase in a two phase specimen, how does the phase boundary area vary with the size of the minority phase particles? 10- For a fixed proportion of each phase in a two phase specimen, how does the phase boundary area vary with the shape of the minority phase particles?