Page 110 - Module DMV20173

5. 0 JOINING PROCESSES

SUMMARY

In this chapter we studied that:

1. fusion welding is defined as melting together and coalescing materials by means of
heat;
2. oxyfuel-gas, arc, and resistance welding are among the most commonly used joining
operations. Gas welding uses burn energy; to supply the necessary heat, arc and

resistance welding use electrical energy instead;
3. in all of these processes, heat is used to bring the joint being welded to a liquid state.
Shielding gases are used to protect the molten-weld pool and the weld area against
oxidation. Filler rods may or may not be used in oxyfuel-gas and arc welding to fill the

weld area;
4. joining processes that do not rely on fusion or pressure at the interfaces include
brazing soldering and adhesive bonding. These processes instead utilize filler
material that requires some temperature rise in the joint. They can be used to join

dissimilar metals of intricate shapes and various thicknesses;
5. adhesive bonding is a joining method to produce good bond strength. Adhesives
have other favorable characteristics, such as the ability to seal, to insulate, to prevent
electrochemical corrosion between dissimilar metals, and to reduce vibration and

noise by means of internal damping in the bond;
6. mechanical fastening is one of the oldest and most common joining methods. Bolts,
screws, and nuts are common fasteners for machine components and structures
which are likely to be taken apart for maintenance, for ease of installations, or for
various other reasons;

7. rivets are semipermanent or permanent fasteners used in buildings, bridges, and
transportation equipment. A wide variety of other fasteners and fastening techniques
is available for numerous permanent or semipermanent applications.

REFERENCES

1. S. Kalpakjian, S.R. Schmid, Manufacturing Engineering and Technology 5 edition,
th
Prentice Hall, 2005.

2. Steve F.Krar Technology of Machine Tools, , Mc Graw Hill, 2005.
3. Howard B. Cary. 2005. Modern Welding Technology. 6th ed. New Jersey: Prentice-
Hall.

BPLK 142 DMV 20173