In addition to the traditional joining processes of oxyfuel-gas and arc welding
a number of other joining processes that are based on producing a strong joint
under pressure and/or heat are available.
° Surface preparation and cleanliness are important in some of these processes
Pressure is applied mechanically or by explosives. Heat may be supplied externally
(by electrical resistance or furnaces), or it may be generated internally (as in friction welding).
° Among important developments is the combining of diffusion-bonding and
superplastic-forming processes. Productivity is improved, as is the capability
to make complex parts economically.
° As in all manufacturing operations, certain hazards are inherent in welding operations. Some relate to the machinery and equipment used, others to the nature of
the process. Proper safety precautions always must be taken in work areas where
welding is done.