Joining Technologies for metals

By Prof. D K Dwivedi   |   IIT Roorkee
Learners enrolled: 949
It is proposed to include following joining technologies of commercial importance under different groups of processes

A) Fundamentals of Metal Joining Technologies: mechanisms for obtaining metallic continuity: fusion, deformation, diffusion, chemical interactions
B) Fusion based processes: principle of fusion welding processes, oxy-fuel has welding, common arc welding processes, laser beam welding, spot welding processes, newer variants of fusion welding processes
C) Solid-liquid joining processes: brazing and soldering, braze welding, cold metal transfer welding,
D) Solid state joining processes: diffusion bonding, ultrasonic welding and explosive welding and
E) Adhesive joining: design, procedure, and applications
F) Metallurgical Aspects of Welding: weld thermal cycle, solidification of weld metal, weldability of carbon steel, alloys steel, stainless steels, and aluminium alloys, Fe-C, CCT and schaffler diagram for understanding the metallurgical transformation in weld and heat affected zone., basics of residual stresses
G) Common issues related with joining technologies their causes and remedies: hardening and softening of heat affected zone, porosity, cracking.

INTENDED AUDIENCE: It is a core course for UG/PG students, practicing engineers.
Course Status : Completed
Course Type : Core
Duration : 8 weeks
Category :
  • Mechanical Engineering
  • Materials Joining
Credit Points : 2
Level : Undergraduate/Postgraduate
Start Date : 25 Jul 2022
End Date : 16 Sep 2022
Enrollment Ends : 08 Aug 2022
Exam Date : 25 Sep 2022 IST

Note: This exam date is subjected to change based on seat availability. You can check final exam date on your hall ticket.

Page Visits

Course layout

Week 1: Introduction: Manufacturing and Joining Fundamental Mechanisms of joining, heat and pressure in joining Classification of joining processes,Heat   generation and power density concept in welding Protection of the weld metal approaches, effect of gases on weld properties

Week 2: Principle of fusion welding processes, oxy-fuel gas welding Fundamentals of welding: type of weld, types of joint, welding position, arc heat generation Physics of welding arc: arc initiation, maintenance, shielded metal arc welding Electrode melting rate, effect of electrode  polarity and welding parameters Gas tungsten arc welding: electrode, shielding gases, Introduction of gas metal arc welding

Week 3: Variants of Gas tungsten arc welding: GTAW, Hot wire GTAW, Flux assisted GTAW  Variants of Gas metal arc welding: Pulse GMAW, CMT welding
Submerged arc welding Electro-slag and Electro-gas welding processes Laser beam welding

Week 4: Brazing Soldering and Braze welding, Fundamentals of resistance welding Resistance welding processes: spot, seam welding  Flash butt welding

Week 5: Adhesive joining, Welding bonding, Solid state joining technologies: Fundamentals Ultrasonic joining, Diffusion bonding

Week 6: Explosive welding, Magnetic pulse welding, Weld thermal cycle, Heat affected zone and weld thermal cycle: I,  Heat affected zone and weld thermal cycle: II

Week 7: Solidification of weld metal, Fundamentals of weldability of metals, Weldability of carbon & alloy steels: Fe-C, CCT,  Weldability of stainless steels:  schaeffler diagram, Metallurgical transformation in weld and heat affected zone of steels

Week 8: Weldability of aluminium alloys: porosity, HAZ softening, PMZ issues, Solidification cracking and their control, Residual stresses in weld joints: effect on joint performance, and control of residual stress,   Cracking of welded joints: solidification and liquation cracks, Cracking of welded joint: cold cracking

Books and references

  1. Metals Handbook-Welding, Brazing and Soldering, American Society for Metals, 1993, 10th edition, Volume 6, USA.
  2. Richard Little, Welding and Welding Technology, McGraw Hill, 2001, 1st edition.
  3. H Cary, Welding Technology, Prentice Hall, 1988, 2nd edition.
  4. S V Nadkarni, Modern Arc Welding Technology, Ador Welding Limited, 2010, New Delhi.
  5. R S Parmar, Welding process and technology, Khanna Publisher, New Delhi
  6. Welding handbook, American Welding Society, 1987, 8th edition, volume 1 & 2, USA

Instructor bio

Prof. D K Dwivedi

IIT Roorkee
D K Dwivedi obtained BE (mechanical engineering), in 1993 from GEC Rewa, ME (welding engineering) from Univ. of Roorkee in 1997 and PhD in Met. Engineering from MNIT, Jaipur in 2003. He has about 9 years teaching experience at NIT Hamirpur and 14 years at IIT Roorkee in subjects related with manufacturing at UG level and welding engineering related subjects at PG level. He has published more than 120 research papers in SCI/SCIE indexed journals and undertaken 20 sponsored research and 50 industrial consultancy projects. He has authored two books entitled Production and Properties of Cast Al-Si Alloys with New Age International, New Delhi (2013) and Surface Engineering with Springer, New Delhi (2018).

Course certificate

The course is free to enroll and learn from. But if you want a certificate, you have to register and write the proctored exam conducted by us in person at any of the designated exam centres.
The exam is optional for a fee of Rs 1000/- (Rupees one thousand only).
Date and Time of Exams: 25 September 2022 Morning session 9am to 12 noon; Afternoon Session 2pm to 5pm.
Registration url: Announcements will be made when the registration form is open for registrations.
The online registration form has to be filled and the certification exam fee needs to be paid. More details will be made available when the exam registration form is published. If there are any changes, it will be mentioned then.
Please check the form for more details on the cities where the exams will be held, the conditions you agree to when you fill the form etc.


Average assignment score = 25% of average of best 6 assignments out of the total 8 assignments given in the course.
Exam score = 75% of the proctored certification exam score out of 100

Final score = Average assignment score + Exam score

YOU WILL BE ELIGIBLE FOR A CERTIFICATE ONLY IF AVERAGE ASSIGNMENT SCORE >=10/25 AND EXAM SCORE >= 30/75. If one of the 2 criteria is not met, you will not get the certificate even if the Final score >= 40/100.

Certificate will have your name, photograph and the score in the final exam with the breakup.It will have the logos of NPTEL and IIT Roorkee. It will be e-verifiable at nptel.ac.in/noc.

Only the e-certificate will be made available. Hard copies will not be dispatched.

Once again, thanks for your interest in our online courses and certification. Happy learning.

- NPTEL team

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