PRIFYSGOL CYMRU ABERTAWE

PRIFYSGOL ABERTAWE

SWANSEA UNIVERSITY School of Engineering

SEMESTER 2 EXAMINATIONS

MAY/JUNE 2009EG-284Manufacturing Technology IILEVEL 2

UNIVERSITY CALCULATORS ONLY Translation dictionaries are not permitted, but an English dictionary may be borrowed from the invigilator on request.

Time allowed:

2 hours

Answer THREE questionsPlease insert any standard constants here.

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Page 1 of 31.(a)Describe two major purposes of numerical modelling applied to manufacturing processes.

[10 marks](b)Using suitable diagrams explain the difference between Euler and Lagrangian schemes when setting up a computational domain.

[5 marks](c)When carrying out a simulation of a forming process what are the most important bulk and surface materials properties required?

[5 marks]

(d)Discuss how metallurgical structure might be included in a process model of forming.

[5 marks]

2.Defects, such as cracks, porosity and inclusions, which may be potentially damaging may be introduced into materials or components during manufacture, and other defects, such as fatigue cracks, may be generated during service. It is necessary to be able to detect and identify such defects and to ascertain their position and size so that decisions can be taken as to whether specific defects can be tolerated or not. A range of non-destructive test methods is available for the inspection of materials and components and the most widely used techniques are:

1. Dye penetrant,

2. Magnetic particle inspection,

3. Eddy current systems,

4. Ultrasonics, and

5. Radiography.

.

(a)Which of the above techniques could be used to assess i) defects breaking the surface of the material and ii) subsurface defects?

[5 marks](b)Describe in detail two of the above NDT techniques.

[10 marks each]

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Page 2 of 3Question 3What is plasma?

[4 marks]

There are two types of plasma machining.

Describe transfer torch, including water submerged machining, its advantages and disadvantages.

[11 marks]

Describe non-transfer torches, highlighting the primary difference to transfer torch, benefits and potential applications i.e. using a transfer torch or a non-transfer torch.

[10 marks]

Question 4.

Describe the process of electric discharge machining.

[12 marks]

What are its advantages and disadvantages?

[8 marks]

Would this process be suitable for the manufacture of plastic injection mould for a model railway engine body[5 marks]

Page 3 of 3