Two surfaces P and Q are to be joined together. In which of the given joining operation(s), there is no melting of the two surfaces P and Q for creating the joint?

Answer :

Solution :

• Soldering is define as a metal joining process wherein coalescence is produced by heating the surface to be joint to a suitable temperature and melting the filler metal which is a fusible alloy called solder (melting point usually less than 427°C).
• Principle underlying soldering is that when the surface to be jointed are cleaned off well from oxides they can be joined together using molten solder that may adhere easily with the workpiece.
• Brazing is also one of the type of welding process which is used for joining the two similar or dissimilar metal piece together by heating the surface and by using a non-ferrous filler metal having its melting point above 427°C but below the melting point of metal to be brazed. The molten filler metal is distributed between the joint surface by the capillary action which on cooling results in a sound joint.