A metal specimen was subjected to a Vickers hardness test. The indentation on the surface of the specimen had a measured diagonal, d, of 0.24mm and the Vickers hardness number was calculated at a value of 482.91kgf/mm². Determine the applied force, F, that was used to test the specimen. Also, determine the Tensile Strength of the metal, assuming it is hard.

QI (a) A tensile stress is to be applied along the axis of a cylindrical steel rod that has a diameter of 7.5 mm. Given the Poisson's ratio, v is 0.30 and the modulus of elasticity, E of the steel is 207 GPa. Determine the magnitude of the load required to produce a 2.5 x10³ mm change in diameter if the deformation is entirely elastic. (b) Referring to the tensile test data tabulated in Table 1, answer the following questions: i. Select with justification the material that will experience the greatest percent reduction in area. ii. Select with justification which material is the strongest. Table 1. Tensile stress-strain data for several hypothetical metals Material Yield Tensile Strain at Fracture Elastic Strength Strength Fracture Strength Modulus (МРа) (MPa) (MPa) (GPa) A 310 340 0.23 265 210 100 120 0.40 105 150 C 415 550 0.15 500 310 D 700 850 0.14 720 210 E Fracture before yielding 650 350

A torsion test shows that the shear modulus of an aluminum specimen is 27.6 GPa. When the same specimen is used in a tensile test, the modulus of elasticity is found to be 73.2 GPa. Find the Poisson’s ratio for the specimen.

Draw a typical stress vs strain tensile test curve for the following material and label the axis. A typical brittle material subjected to a tensile stress that has been applied to the material till the sample breaks. 1- label the axis and draw the curve for a brittle material. 2- indicate the maximum strength of the material. 3- show on the portion of the curve where young's modulus can be calculated.