QEEE D2S Session On
Joining Processes- Manufacturing Technology
25th, 27th September & 9th October, 2017
A QEEE D2S (Direct to Student) Session on “Joining Processes- Manufacturing Technology” was conducted on 25th, 27th September & 9th October 2017 with an objective to acquaint students with the Fundamentals and Applications of various Joining Processes. The session was hosted by Dr. Sushanta Panigrahi from IIT Madras. Prof. DV Bhise, at Dronacharya Group of Institutions, Greater Noida coordinated the session as the Local Faculty Coordinator which was attended by the students of 5th semester ME.
Session 1: September 25, 2017
Dr. Sushanta Panigrahi initiated the session by explaining the relevance of joining process and its industrial applications. He then briefly introduced joining of metals. He gave examples of multiple parts that are assembled together as a single product by using various joining processes. He also gave short description of the following joining processes:
- Brazing and Soldering
- Adhesive, bonding and
- Mechanical Fastening
Prof. Panigrahi continued the discussion on Fundamentals of Welding: How does welding happen, what is the difficulty for maintaining material continuity? How to maintain continuity for a perfect weld?
He further discussed Liquid state welding processes- Arc and Gas welding in detail with their mechanism and density of the heat source required. With the help of examples, Dr. Panigrahi explained the difference between Arc and Gas welding from application point of view. Students took keen interest in the session and asked questions on welding electrodes, use of flux and shielding gases. Dr. Panigrahi answered students’ questions by giving suitable examples.
Session 2: September 27, 2017
Dr. Panigrahi initiated the session by summarizing the first session. He summarized liquid state welding processes. He then started discussion on various types of arc welding processes like: Shielded metal arc welding, Submerged arc welding, Flux cored arc welding and Gas -Tungstan arc welding. He further elaborated on the use of non-consumable electrode in arc welding and its advantages as compared to consumable electrodes. There was also a discussion on use of Inert gas to protect the weld pool from atmospheric gases.
Dr. Panigrahi continued the session with a discussion on Plasma arc welding and other High density welding processes like Laser beam and Electron beam welding. He demonstrated Laser beam welding with the help of a video. He elaborated further that these processes are useful as there is narrow HAZ (Heat Affected Zone) due to concentrated arc and also all common metals can be welded.
Session 2: October 9, 2017
Dr. Panigrahi initiated the third and last session of the course by giving a brief recap of the previous two sessions. He briefed the participants on the major differences between Liquid State and Solid State welding processes. He then discussed about the concept of Solid-Liquid State Welding. He explained the process as melting of non ferrous metal (filler metal) and then drawing it into the space between two solid surfaces to be joined. He then discussed two solid – liquid sate welding processes – Soldering and Brazing with their working principle, type of filler material used and joint strength. He pointed out some peculiar features of Brazing and Soldering as two dissimilar metals can also be joined, less HAZ problem as there is no need to heat the base metal.
During the last half of the session Dr. Panigrahi initiated discussion on various welding defects and their analysis. He classified defects i.e., - Surface defect, Internal defects and Structural defects. He discussed major causes and remedies of these defects in detail. He further pointed that if the major causes are not addressed properly then it may lead to failure of the welded joints.
Discussion was also held on Residual Stresses and Distortion with the help of Case Studies. The discussion was followed by question answer session in which remedies to prevent distortion were proposed.
The sessions were full of practical information on joining processes and their applications. Students’ knowledge base has expanded and the knowledge gained shall be definitely helpful in assembling various structures during their study as well as in their career.