JNTU B.Tech Examinations, FOUNDRY AND WELDING, Aug/Sep 2008
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
1. (a) What are the common materials used for making patterns? Why some materials are preferred to others in making patterns used in a mechanized foundry?
(b) Explain why the following allowances are provided: draft allowance, shrinkage
allowance, and machining allowance.
(c) What are the common pattern making methods? [6+6+4]
2. (a) What are the property requirements of cores? How the required property set
is obtained by adjusting the composition of core sands?
(b) What are stock cores? How are they made?
(c) Differentiate between the composition, properties, shelf live of oil, sand and
shell sand cores [6+4+6]
3. (a) What is liningless cupola? How is cupola shell is water cooled?
(b) Draw a sketch of water cooled cupola and its accessories. [6+10]
4. Lay out an algorithm based on the principles of gating system design to feed an
arbitrary mold cavity with liquid metal. 
5. (a) Name two gas welding techniques and explain their principle and applications.
(b) Discuss various types of flames used in gas welding process. Suggest their
specific applications. [8+8]
6. Write an essay on ‘Testing of adhesive bonded joints’. 
7. With the help of a neat sketch, describe the working of a ram injection molding
process. List out the advantages and disadvantages of the process over other methods of processing of plastics. Also give the important applications of this process.
8. (a) Why is particle size is of great importance in powder metallurgy? What do
you know about different classes of powders in powder metallurgy? Explain.
(b) Discuss the electrolytic method of copper powder production indicating its
advantages, the principle on which the method is based, the main variables
affecting the properties of the powder and technology of the process. [6+10]