I have three Materials question: (please give simple answer) Question 8. What are some important mechanisms to increase the strength of metals? Give examples. Question 9. A cylindrical bar of 10.00 mm diameter of some metal is deformed elastically by an axial tensile load of 15,000 N. The diameter of the bar decreases by 0.07 mm subsequent to the load application. (a) Compute Poisson’s ratio for this material if its elastic modulus is 100 GPa. (b) What is your best guess on the material being tested? Question 10. A tensile test is performed on a metal and it is found that a true plastic strain of 0.2 is produced for a true stress of 575 MPa. The value of the strength coefficient for this metal is 860 MPa. (a) Determine the value of the strain hardening exponent for this metal. (b) Calculate the value of true stress for the same metal if the true strain is increased to 0.3. (Hint: the equation of the plastic portion of the true stress – true strain curve is given as: )
