1. Determine the material index for following problem.
Floor joist beam with strong enough and minimum cost is required.
2. Material index showed that it need to draw the line with slop of 3on Modulus-Density graph when material index is Mp = E1/3/p. Prove this is true.
3. Explain why ductile metallic material is getting thinner in transverse direction when it is elongated in loading direction. Your answer should include entire mechanism of plastic deformation.
4. The lattice resistance of copper, like that of most FCC metals, is small. When 10% of nickel is dissolved in copper to make a solid solution, the strength of the alloy is 150 MPa. What would you expect the strength of an alloy with 20% nickel to be?
5. A metal-matrix composite consists of aluminum containing hard particles of silicon carbide (SiC) with a mean spacing of 3 µm. The composite has strength of 180 MPa. If a new grade of the composite with a particle spacing of 2 µm were developed, what would you expect its strength to be?
6. Nanocrystalline materials have grain sizes in the range 0.01-0.1 µm. If the contribution of grain boundary strengthening in an alloy with grains of 0.1 µm is 20 MPa, what would you expect it to be if the grain size were reduced to 0.01 µm?