JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

Overview

Course objectives: This course is mainly intended to introduce and explain various moulding, casting techniques and equipment used. Principles of Solidification of casting, defects in castings and their remedies are also dealt in detail. This course also provides in depth knowledge about various metal joining techniques, the thermal and residual stresses associated with, the equipment used, their modern developments, and defects of weldments.

Course outcome: At the end of this course the student will be able to

• 1. Understand basics of metal casting, casting defects and remedies.
• 2. Design gating system for metal casting processes
• 3. Understand the casting technology, solidification of metals and alloys.
• 4. Understand the basics of various metal joining processes
• 5. Understand weldability of cast iron and high carbon steel and weldability characteristics.

UNIT - I

Introduction to Foundry – Types of Foundries, Patterns: Materials for patterns, types of patterns; functions and pattern allowance. Moulding materials; moulding sands, properties and selection of materials and additives Moulding Processes: Green and dry sand moulding; shell moulding, CO2 moulding. Core making. Gating, Risering and their design.

UNIT - II

Casting Methods: Permanent mould casting, pressure die-casting, Gravity die casting, Vacuum die casting, centrifugal casting, Investment Casting, Squeeze casting and Composite Casting, Casting defects arising due to moulding, cores, melting and pouring practice. Inspection and Testing of castings.

UNIT - III

Melting and Solidification: Cupola and Induction Melting. Nucleation and growth. Freezing of metals and alloys. Dendritic freezing. Progressive and Directional Solidification. Classification of welding processes: Principles, advantages disadvantages and fields of application of the following welding processes: Gas Welding, Arc Welding processes, MMAW, GTAW, MIG, SAW and Resistance Welding

UNIT - IV

Metal Joining Techniques: Principles, advantages disadvantages of Electron Beam Welding, Laser welding, Solid state welding, Friction stir welding, and explosive welding processes.

UNIT - V

Weldability, Microstructure of fusion zone and heat affected zone. Influence of heat input, thermal and residual stresses, pre heat and cooling rate, PWHT. Weldability of high carbon steel, cast irons, stainless steels use of Schaeffler diagram and Delong diagrams. Welding of non-ferrous alloys - Aluminum alloys, Welding of dissimilar metals.

TEXT BOOKS:

• 1. Principles of Metal casting by Heine – Loper and Rosenthal, Tata McGraw Hill, 2nd Edition.
• 2. Metal Casting: Principles and practice – T.V. Ramana Rao, New Age International, 2007.
• 3. Welding Technology – R.S. Parmar R18 B.TECH MME III YEAR

REFERENCE BOOKS:

• 1. Metals Handbook Vol. 5 published by ASM, Ohio.
• 2. Manufacturing Technology – Vol. I: Foundry, Forming and Welding, P.N.Rao, McGraw Hill 3rd Edition.
• 3. Castings – John Campbell – Second Edition – Elsevier.
• 4. Welding Metallurgy - JF Lancaster R18 B.TECH MME III YEAR