MSE 201 Material Science Assignment Make Up Exam 2017
Questions are based on Callister & Rethwisch, Materials Science and Engineering: An Introduction, 9th Edition
1-14 question: 5 point each
14-18 questions: 7.5 point each
- The chemical composition of the repeat unit for nylon 6,6 is given by the formula C12H22N2O2. Atomic weights for the constituent elements are AC = 12, AH = 1, AN = 14, and AO = 16. According to this chemical formula (for nylon 6,6), what is the percent (by weight) of carbon in nylon 6,6 ? What type(s) of bonding would be expected for bronze (a copper-tin alloy)?
- What are the Miller indices for the plane shown in the following cubic unit cell?
- A hypothetical metal has the BCC crystal structure, a density of 7.24 g/cm3, and an atomic weight of 48.9 g/mol. What is the atomic radius of this metal?
- Calculate the number of vacancies per cubic meter at 1000°C for a metal that has an energy for vacancy formation of 1.22 eV/atom, a density of 6.25 g/cm3, and an atomic weight of 37.4 g/mol.
- What is the composition, in weight percent, of an alloy that consists of 94.1 at% Ag and 5.9 at% Cu? The atomic weights for Ag and Cu are 107.87 g/mol and 63.55 g/mol, respectively.
- Calculate the diffusion coefficient for copper in aluminum at 600C. Preexponential and activation energy values for this system are 6.5 10–5 m2/s and 136,000 J/mol, respectively.
- Atoms of which of the following elements will diffuse most rapidly in iron?
- A cylindrical specimen of brass that has a diameter of 20 mm, a tensile modulus of 110 GPa, and a Poisson’s ratio of 0.35 is pulled in tension with force of 40,000 N. If the deformation is totally elastic, what is the strain experienced by the specimen?
- The following figure shows the tensile stress-strain curve for a plain-carbon steel.
(a) What is this alloy’s tensile strength?
(b) What is its modulus of elasticity?
(c) What is the yield strength?
- Plastically deforming a metal specimen near room temperature generally leads to which of the following property changes?
(A) An increased tensile strength and a decreased ductility
(B) A decreased tensile strength and an increased ductility
(C) An increased tensile strength and an increased ductility
(D) A decreased tensile strength and a decreased ductility
- A dislocation formed by adding an extra half-plane of atoms to a crystal is referred to as a (an)
(A) Screw dislocation
(B) Vacancy dislocation
(C) Interstitial dislocation
(D) Edge dislocation
- Estimate the theoretical fracture strength (in MPa) of a brittle material if it is known that fracture occurs by the propagation of an elliptically shaped surface crack of length 0.25 mm that has a tip radius of curvature of 0.004 mm when a stress of 1060 MPa is applied.
- Which type of fracture is associated with intergranular crack propagation?
(C) Either ductile or brittle
(D) Neither ductile nor brittle
- Once a system is at a state of equilibrium, a shift from equilibrium may result by alteration of which of the following?
(D) All of the above
- From the lead–tin phase diagram given below which phases/phase combinations is present for an alloy of composition 46 wt% Sn–54 wt% Pb that is at equilibrium at 44oC?
- On the basis of accompanying isothermal transformation diagram for a 0.45 wt% C iron-carbon
alloy, what is the heat treatment used to isothermally convert a microstructure that consists of proeutectoid ferrite and fine pearlite into one that is composed of proeutectoid ferrite and martensite?
- Schematic room-temperature microstructures for four iron–carbon alloys are as follows. Rank these microstructures (by letter) from the hardest to the softest.
Course: MSE 201 Structure and Properties of Engineering Materials
School: North Carolina State University