Question

Problem 1 (10 pts) It is required to manufacture a 2.5 mm diameter copper rod from larger diameter stock by drawing. The rod should have a tensile strength of 300 MPa or more, a yield strength of 200 MPa or more, and ductility of 10% or more. Determine (a) the range of%CW which will allow achieving those properties, and (b) within this range clearly pick a certain%CW and determine the corresponding diameter of the starting stock. yield strength (MPa) tensile strength (MPa) ductility (%EL) en cu cu 100ELULUI 0 20 40 60 % Cold Work 0 20 40 60 % Cold Work LLLLL 0 20 40 60 % Cold Work Problem 2 (10 pts) A single crystal rod is to be loaded in tension along its axis. For a particular slip system, the angle between the loading direction and the slip direction is 30' and that between the loading direction and the normal to the slip plane is 60°. The critical resolved shear stress for this metal is 18 MP. What is tensile stress necessary for yielding? Problem 3 (10 pts) What is meant by a slip system. List all the slip systems in FCC metals Problem 4 (10 noints. What is the main mechanism of deformation in metale? Tist three methode se!

Answer 1

- a) 6) 251. For Tensile strength of 300 MPa ok more 7.cu> Tor yield strength of 200 mile or more r.cu> 10% for ductility 10% on mose / CW 32 so range should 251 L CW L 32% ca. het l. cw = 28% 28%. = (A o- A f/10 II do - 1 I dat = (do ² dp ²)x100 No I do 0.28 - 1 0 .12 and do dog - Ido 2.948 mm O Ao 0.72 072