Course Content:

Types of welding: Fusion welding process, Resistance welding, Chemical fusion welding, Beam welding process, Friction welding, Pressure welding. Thermal analysis of weldment: Modes of heat transfer during welding, Temperature profile in welding process. Fluid flow analysis of weldment: Forces contribution during welding, Convection. Microstructure evolution in welding: Thermodynamics of solidification, Driving force for solidification, Phase diagram of alloys, Constitutional undercooling, Microstructures in weld. Zones in a weldment: Peak temperature, Cooling rates, Zones in fusion welding, Effect of weld pool shape on microstructure. Stresses in welding: Residual stresses in welding, Distortion. Weld joint design: Type of weld joints, Weld design guidelines, Size of weld, and amount of welding. Other joining processes: Adhesive bonding and their mechanism, Welding of dissimilar materials, Welding polymers, and other non-metallic materials. Defects in welding and weld testing: Welding defects, Weldability testing.

Lecture wise Breakup (based on 60 min per lecture)

I. Introduction to welding and welding processes (6 Lecture)

• Overview of welding, Requirements for ideal weld, Types of welding, Fusion welding process, Arc welding, Resistance welding, Chemical fusion welding, Beam welding process, Microwave welding, Solid state joining processes, Friction welding, Pressure welding, Ultrasonic and electromagnetic weldingIntroduction to the course. [6 Lecture]

II. Thermal analysis of weldment (6 Lectures)

• Recalling of basic heat transfer, Modes of heat transfer during welding, Temperature profile in arc welding, Moving heat sources and pseudo-steady state, Simplified solution for a fast-moving high-power source in thin/thick plate, Temperature profile in spot, friction and thermit welding. [6 Lectures]

III.Fluid flow analysis of weldment (4 Lectures)

• The basics of fluid mechanics in welding, Forces contribution during welding, Gravity driven convection (thermal + solutal) and their effects, Marangoni convection, Electromotive forces, Frictional forces, Weld pool evaporation. [4 Lectures]

IV. Microstructure evolution in welding (4 Lectures)

• Thermodynamics of solidification, Driving force for solidification, Phase diagram of alloys, Solidification of materials, Constitutional undercooling, Microstructures in weld. [4 Lecture]

V. Zones in a weldment (4 Lectures)

• Peak temperature, Cooling rates, Zones in fusion welding, Effect of weld pool shape on microstructure, HAZ microstructure and strength evolution during fusion welding, HAZ microstructure and strength evolution during friction welding. [4 Lectures]

VI. Stresses in welding (3 Lectures)

• Origin of thermal stresses, Residual stresses in welding, Distortion . [3Lectures]

VII. Weld joint design (3 Lectures)

• Type of weld joints, Weld design guidelines, Size of weld, and amount of welding. [3Lectures]

VIII. Welding of dissimilar materials (3 Lectures)

• Welding of dissimilar materials, Welding polymers, and other non-metallic materials. [3Lectures]

IX. Other joining processes (2 Lectures)

• Adhesive bonding and their mechanism, Diffusion welding, Brazing, Soldering. [2Lectures]

X. Defects in welding and weld testing (2 Lectures)

• Welding defects, Weldability testing, HAZ cold-cracking tests, Weld pool shape Tests, Weld cracking test. [2Lectures]

XI. Demonstration / case studies (2 Lectures)

• A few welding process demonstrations, Case studies of selected joining techniques, and related numerical studies. [2Lectures]

References:

1. Principles of Welding, R. W. Messler, John Wiley & Sons, 2008, ISBN: 9783527617494

2. Principles of Welding Technology, L. M. Gourd, Third Edition, Viva Books Private Limited, 2004, ISBN: 9788176490290

3. Phase transformations in metals and alloys, D. A. Porter and K. E. Easterling, Second edition, CRC Press, 1992, ISBN: 9780748757411

4. Heat conduction, D. W. Hahn and M. N. Özisik, Third Edition, John Wiley & Sons, 2012, ISBN: 9781118330111

5. Fundamentals of solidification by W. Kurz and D. Fisher, Fourth edition, Trans Tech Publications Limited, 1998, ISBN: 9783035732399

6. Welding Metallurgy, S. Kou, Second edition, John Wiley & Sons, 2003, ISBN: 9780471460930

7. Metallurgy of welding, J. F. Lancaster, Third Edition, Springer Science & Business Media, 2012, ISBN: 9789401095068

8. Manufacturing Science, A. Ghosh, and A. K. Mallik, Second edition, EastWest Press, 2010, ISBN: 9788176710633