PDE40001 Manufacturing Systems and Design
Task:
1. You are required to make some parts as shown in Figure 4 (b). Several processes are required to manufacture the part from its initial slug. Determine dimension of initial slug and the cold forging parameters of all process. The material used is a medium carbon steel (0.36%C) with the stress strain curve provided in Figure 2. Provide some insight regarding the basis of the process selection and the sequence (e.g. reason why you choose contained bar extrusion instead of free forward extrusion). Hint: Two processes are required to manufacture the semi-finished part
2. An existing 2-component die assembly has an insert radius of X mm and a ring outer radius of Y mm. The insert and the ring were pre-stressed by interference fit resulting in a contact pressure, Pk at the interference diameter. The die working pressure of this 2-component assembly was 1000 MPa when the extrusion process was carried out. Answer the following questions making use of a graph paper.
(a) Find the value of the interference diameter.
(b) Find the value of Pk
(c) Calculate the equivalent stress.
(d) Choose suitable materials for the dies, and explain the basis of your selection* X and Y values depended on the last digit of your Student ID as follow:
Student ID ended with 0 or 1: X=15, Y=60
Student ID ended with 2 or 3: X=15, Y=120
Student ID ended with 4 or 5: X=20, Y=80
Student ID ended with 6 or 7: X=12.5, Y=40.5
Student ID ended with 8 or 9: X=60, Y=240
