a. A metal such as steel has on the order of 1010' dislocations per square millimeter. If you were able to reduce this to around 10dislocations per square millimeter, the

material.would be: a1. Stronger a2. Weaker What type of bond is found between atoms within hydrocarbon molecules? bị. Ionic b2. Covalent b3. van der Waals b4. Metallic c. Amorphous thermoplastics are formed above their: c1. Glass transition temperature.C2. Melting temperature.c3. Softening point.C4. None of the above, d. How does a dislocation allow for deformation? di. Strain energy near the dislocation makes it easier to break atomic bonds allowing planes of atoms to slip.-----d2. The dislocation allows atoms to diffuse to the empty space in the lattice. The diffusion is enhanced by applied stress which causes deformation.------d3. Dislocations allow for the stretching of atomic bonds to make a material more elastic.-----d4. Dislocations have a more stable energy state that allows atoms to move more freely under applied stresses. . How many cycles indicate low-cycle fatigue? eт. 10 e2. 10° сз. 108 f. What is the carbon concentration of 5450 alloy steel? fj. 0.054 wt% f2. 0.05 wt% f3. 0.54 wt%f4. 0.5 wt%fs. Trick question, not a steel g. The diffusion of carbon within ferrite is faster than the diffusion of carbon within austenite because: gi. Ferrite exists at a higher temperature than austenite .g2. Ferrite is a BCC structure which has more space for diffusion. g3. Diffusion happens faster in austenite. g4. Diffusion will not occur in austenite under any conditions. h. Which of the following strengthening-mechanisms can be removed by annealing? hj. Grain size reductionh2. Strain hardeningh3. Solid solution strengtheningh4. Super-solution treatment i. Which of the following strengthening processes tend to produce an increase in both strength and toughness? ij. Grain size reduction.i2. Strain hardening.i3. Solid solution strengthening.i4. Super-solution treatment. j. Which of the following material categories is most likely to be amorphous: ji. Metalsj2. Ceramicsj3. Polymers