In a bronze alloy sample, the stress where plastic deformation just starts is 280 MPa and the elastic modulus is 115 GPa. What is the maximum load that may be applied to a specimen with a cross-sectional area of 325 mm² without plastic deformation? If the initial specimen length is 120 mm, what is the maximum length to which it may be strained without causing plastic deformation? Is it possible to consider the stress given in this problem, 280 MPa, as a yield strength? Why?
4. A single crystal of a metal that has the FCC crystal structure is oriented such that a tensile stress is applied parallel to the [110] direction. If the CRSS is 2.2 MPa, calculate the magnitude of applied stresses necessary to operate slip on the 111 plane in each of the [110], [101], and [011] directions. Which system is the primary slip system? Why?
5. Generally, the strength of metals can be enhanced using several methods. Introduce these methods. Explain how the grain boundaries and grain size influence the strength in metals.