JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Tech II AIRCRAFT PRODUCTION TECHNOLOGY Previous Question Paper (December - 2018 - R15)

Electron beam welding (EBW) is a fusion welding process that utilizes a high-velocity stream of electrons to generate heat. The principle involves focusing a beam of electrons onto the joint between two workpieces in a vacuum environment. As the high-energy electrons strike the material, their kinetic energy is converted into intense heat, causing the metal to melt and fuse together instantaneously.

Centrifugal casting is a manufacturing process where molten metal is poured into a rapidly rotating permanent mold. The rotation creates a strong centrifugal force that throws the molten metal against the inner walls of the mold, where it solidifies.

The process follows these key steps:

1. The mold is mounted on a machine and rotated at high speed about its axis.
2. Molten metal is introduced into the rotating mold, usually through a central pouring basin or spout.
3. The centrifugal force ensures the metal is distributed uniformly and forced against the mold walls, resulting in high-density castings with minimal impurities, as lighter inclusions are pushed toward the center.
4. Once the metal has solidified, the mold rotation is stopped, and the casting is removed.

This method is primarily used for producing hollow, cylindrical components such as pipes, cylinder liners, and bushings, offering excellent mechanical properties and structural integrity.