Material Science Question Bank 346e3v

Centurion University of Technology and Management Paralakhemundi Question bank for Material Science for Chemical Engineering (For B.Tech V Semester – Chemical Engineering) Prepared by P.Sirish chand Short questions 1. 2. 3. 4. 5. 6.

DEFINE coordination number. WHAT is atomic packing factor? EXPLAIN about miller indices. STATE the five types of bonding that occur in materials and their characteristics STATE the three lattice-type structures in metals Given a description or drawing, DISTINGUISH between the three most common types of crystalline structures.

7. DEFINE the following : a. Crystal structure b. Body-centered cubic structure c. Face-centered cubic structure d. Hexagonal close-packed structure 8. IDENTIFY the crystalline structure possessed by a metal. 9. DEFINE the term polymorphism. 10. DEFINE the term alloy. 11. DESCRIBE an alloy as to the three possible microstructures and the two general characteristics as compared to pure metals. 12. IDENTIFY the two desirable properties of type 304 stainless steel. 13. IDENTIFY the three types of microscopic imperfections found in crystalline structures. 14. WHAT is the classification of engineering materials? 15. WHAT is packing efficiency? 16. DEFINE burgers vector? 17. WHAT is Schottky defect? 18. WHAT is the Minimum number of slip systems that must be operative during plastic deformation? 19. EXPLAIN a martensitic transformation? 20. WRITE the constituents of the eutectoid mixture of steel? 21. DEFINE recrystallization temperature. 22. CALCULATE the maximum number of phases that can coexist in equilibrium in a single component system. 23. CALCULATE the degree of freedom when ice, water and water vapour co-exist in equilibrium? 24. DEFINE the following a. liquidus b. Solidus c. Solvus 25. DEFINE the term `dislocation’. 26. WHAT are the units of surface energy of a grain boundary? 27. WHAT is lever rule? 28. WRITE the phase rule? 29. DEFINE Elastic, Anelastic and Visco elastic behavior. 30. WRITE the type of defects in solids? 31. DEFINE the following : a. Stress b. Tensile stress c. Compressive stress d. Shear stress e. Compressibility 32. DISTINGUISH between the following types of stresses by the direction in which stress is applied. a. Tensile b. Compressive c. Shear 33. DEFINE the following : a. Strain b. Plastic deformation c. Proportional limit 34. IDENTIFY the two common forms of strain. 35. . DISTINGUISH between the two common forms of strain as to dimensional change. 36. STATE 37. STATE Hooke's Law. 38. DEFINE Young's Modulus (Elastic Modulus) as it relates to stress. 39. Given the values of the associated material properties, CALCULATE the elongation of a material using Hooke’s Law. 40. DEFINE the following : a. Bulk Modulus

b. Fracture point 41. Given stress-strain curves for ductile and brittle material, IDENTIFY the following specific points on a Stress-strain curve a. Proportional limit b. Yield point c. Ultimate strength d. Fracture point 42. . Given a stress-strain curve, IDENTIFY whether the type of material represented is ductile or brittle. 43. . Given a stress-strain curve, INTERPRET a stress-strain curve for the following: a. Application of Hooke's Law b. Elastic region c. Plastic region 44. DEFINE the following : a. Strength b. Ultimate tensile strength c. Yield strength d. Ductility e. Malleability f. Toughness g. Hardness 45. IDENTIFY how slip affects the strength of a metal. 46. DESCRIBE the effects on ductility caused by: a. Temperature changes b. Irradiation c. Cold working 47. IDENTIFY the reactor plant application for which high ductility is desirable. 48. STATE how heat treatment affects the properties of heat-treated steel and carbon steel. 49. DESCRIBE the adverse effects of welding on metal including types of stress and method(s) for minimizing stress 50. STATE the reason that galvanic corrosion is a concern in design and material selection. 51. DESCRIBE hydrogen embrittlement including the two required conditions and the formation process. 52. IDENTIFY why zircaloy-4 is less susceptible to hydrogen embrittlement than zircaloy-2.

Long questions 1. How Engineering materials are classified on the basis of chemical nature and atomic structure. Give characteristic properties, application and example under each category. 2. (a) Calculate the radius of the largest atom which could exist interstitially in FCC lead without crowding. (b) What is the coordination number of the interstitial site? 3. Discuss about the effect of alloying elements on the properties of steel 4. (a) State the different types of bonds and their characteristics. Describe them in detail by giving examples. (b) Define electron affinity and electro negativity. 5. (a) Draw a two dimensional pentagonal lattice. (b) Draw a FCC lattice unit cell. Connect the face centered lattice points (at opposite ends of a cube body diagonal) and show that the result is a primitive Cell. 6. What are composite materials? What are the different types of composite materials? Describe each of them. 7. What are the outstanding properties of nickel? Give one application and the reason for selection of the following nickel alloys: Monel metal, Constantan, Hastelloy D, Inconel, Hastelloy A and Hastelloy C. 8. (a) Discuss about the metals used for high temperature service. (b) What are the alloys and metals used in chemical industry? Discuss. 9. Calculate the coulombic attractive force between a pair of Na+ and Cl- ions that just touch each other. Assume the ionic radius of the Na+ ion to be 0.095 nm and that of the Cl- ion to be 0.181 nm. 10. Determine the Miller indices of the cubic crystal plane that intersects the position coordinates (1,1/4,0), (1,1,1/2), (3/4,1,1/4), and all coordinate axes. 11. An X- ray diffractometer recorder chart for an element that has either the BCC or the FCC crystal structure shows diffraction peaks at the following 2θ angles: 40,58,73,86.8,100.4 and 114.7. The wavelength of the incoming x-ray used was 0.154 nm. a. Determine the cubic structure of the element b. Determine the lattice constant of the element c. Identify the elment 12. (a) State the application and limitations of phase rule? (b) What is eutectic point? Explain its significance giving an example 13. Describe the transformation of austenite to martensite and compare it to pearlitic and bainitic transformation. 14. (a) What is dislocation climb? (b) Explain jogs in dislocation. (c) Explain Frank-Read source of dislocation. 15. (a) Define phase and phase rule. (b) In a binary phase diagram (pressure omitted), what is the maximum number of phases that can coexist for at least one degree of freedom? c) Give the number of variables and the degrees of freedom at the peritectic temperature of a binary phase diagram. 16. Distinguish among the direction of the dislocation line, the Burgers vector and direction of dislocation motion for: (a) an edge and (b) a screw Dislocation. 17.(a) Describe the time-temperature-transformation characteristics of the eutectoid steel with a suitable diagram. (b) Discuss about the effect of alloying elements on the properties of steel. 18. (a) What is viscoelastic behavior? In which material is it commonly found? (b) Explain the macroscopic models of Maxwell and Voigt-Kelvin used to describe viscoelastic behavior of materials. 19. Draw Fe-Fe3 C phase diagram and label the various points, lines and areas in it. 20. The energy stored by strain hardening in a metal is 4* 104 cal/m3. Given that the shear modulus is 4* 1010 N/m2, b= 2.8* 10−10 m and υ =1/3, Calculate the dislocation density. Assume that the edge and screw dislocation densities are equal.

21. Determine the weight percent and composition in weight percent of each phase present in a Fe - 4.2 wt% Ni alloy at 1517oC+ΔT. 22. (a). Discuss the effect of cold work, recovery, recrystallization and grain growth on the properties like tensile stress, electrical conductivity and ductility of crystalline materials. (b) Describe the phenomenon of grain growth and state the factors affecting grain growth. 23.(a).Discuss about the characteristic creep curves with a neat figure. (b) Explain various mechanisms of creep. (c) Write about dispersion hardening as an effective method of improving creep resistance. 24. (a) Define shear modulus and bulk modulus. (b) Discuss about the Young’s modulus as a parameter in design 25. (a) Explain how a fatigue fracture occurs and give examples of fatigue fracture. (b) Suggest ways to improve the fatigue life of a component. (c) Discuss about creep resistant materials. 26. (a) Define elastic deformation and anelastic deformation. (b) Define shear modulus and bulk modulus. (c) Describe the creep and stress relaxation experiments on a Maxwell element and sketch the corresponding curves for both the experiments. 27. How do you expect dislocation motion to be effected by grain boundaries? Explain 28. (a). If a tensile force of 10 N is applied to a specimen of length 100 mm, width 10 mm and thickness 1mm, what is the tensile stress developed in the specimen? (b) A test piece is 100 mm long. It is subjected to 0.2 % strain. What would be its length at this strain level? 29. A fatigue test is made with a mean stress of 120 Mpa and stress amplitude of 165 Mpa, Calculate (a) the maximum and minimum stresses, (b) the stress ratio (c) The stress range. 30. Determine the critical crack length (mm) for a through crack in a thick 2024-T6 alloy plate that has a fracture toughness KIC =23.5 MPa m1/2 and is under a stress of 300 MPa. Assume Y = 1 31. Compute the engineering stress and strain with the true test and strain for the tensile test of a low - carbon steel that has the following test values. Load applied to specimen = 75 kN, Initial specimen diameter = 12.5 mm, Diameter of specimen under 75 kN load = 12 mm.