Model-Exam Questions 1. Discuss why materials characterization is required in relation to the modern material’s needs and challenges. 2. Briefly elaborate configuration of scanning electron microscope (SEM) and explain its operating principles a. Demonstrate similarities and differences - with Optical microscope, TEM and AFM b. Information acquired from SEM analysis and its potential applications c. General sample preparation for SEM analysis d. Interaction of electrons with specimen/sample (Fig 1); and explain the role of different types of signals (e.g., BSE, SE and x-rays) generated and transmitted electrons. What information do these signals provide? Also, explain how the area from which these signals originate affect the information acquired from the analysis? Figure 1: Emission of various electrons and electromagnetic waves from/through the specimen 3. Explain the fundamentals of XRD in relation to the generation and detection of x-rays, crystal arrangements and nature of samples to be analyzed (bulk, powder, thin films, poly-crystals, single crystals). In relation with the above question, discuss the following briefly a) How x-ray diffraction peaks are produced and diffracted from each set of lattice planes in a sample b) Sample preparation for powder diffractometry 4. Discuss and demonstrate the operating principles and techniques of FTIR, and also explain similarities and differences - with Attenuated Total Reflectance (ATR) and Diffuse Reflectance Fourier Transfer Infrared Spectroscopy (DRIFTS) 5. Calorimetry is a technique for determining the quantity of heat that is either absorbed or released by a substance undergoing thermal transitions and looks at how a material’s heat capacity (Cp) is changed by temperature. a. Explain briefly and demonstrate how DSC works b. If any, explain the difference between DSC and DTA techniques c. What are the strengths and limitations of DSC technique d. Discuss the potential applications of DSC techniques 6. What is the difference between engineering stress and true stress in a tensile and compression test? Explain.
