The two most basic welding forms we know for creating metals are TIG (Tungsten Inert Gas) welding and MIG (Metal Inert Gas) welding. The other name for TIG is GTAW (Gas Tungsten Arc Welding) and MIG likewise is regularly alluded to as GMAW (Gas Metal Arc Welding). The third is Arc Welding that is a sort of welding that uses a welding control supply to make an electric circular segment between a terminal and the base material to soften the metals at the welding point. You can utilize either immediate (DC) or rotating (AC) present and consumable or non-consumable terminals. The expression "Metal" in Gas Metal Arc Welding signifies the wire that is utilized to make the curve.
2.4 SPOT WELDING 2.4.1 Principle of Spot Welding Resistive spot welding is a course of during which contacting metallic surfaces are joined by the heat obtained from resistance to electrical present. Work-items are held collectively under strain exerted by electrodes. In general the sheets available are in the range of 0.5 to 3 mm thickness. The strategy makes use of two shaped copper alloy electrodes to pay attention welding present right into a small "spot" and to concurrently clamp the sheets collectively. Forcing a giant present by the spot will melt the metallic and kind the weld.
ABSTRACT Distortion is the main problem of welding industry. This problem can be solved by variety of techniques such as heat sinking and side heating. During the heating and cooling cycle thermal strains occurs in the weld and adjacent area. The strains produced during the heating stage of welding are always accompanied by plastic deformation of the metal. The stresses resulting from these strains combine and react to produce internal forces that cause a variety of welding distortions.
The results were analyzed by means of tensile, Rockwell hardness test and metallographic tests. Solid state welding processes are characterized by the absence of melting and the formation of narrow heat affected zone (HAZ). The metallurgical properties are usually
c) Ultrasonic welding – is a solid-state process where a joint is formed through the use of vibratory energy. d) Friction welding – creates a joint, where the relative motion of the two interfaces of the materials produces the heat for welding. Mechanical energy is directly converted to thermal energy without
But temperature at the bottom surface is still enough for burning of the insulating material which was touched to the inner wall. Burning or melting of the insulating material is not desirable; this indicates that at the time of welding the temperature developed at the lower surface must be less than the melting temperature of the insulating material. During the welding process temperature varies with respect to time, thus it is very difficult to predict the temperature profile by numerically. But this analysis can be done easily and effectively by finite element analysis. The governing equation for transient thermal analysis is given
While carrying out Friction stir welding on two dissimilar metals the conductivity increases and corrosion reduces. However in stir welding the metal can’t be welded again . Even though Aluminum is heated to 359°C and copper was done at 560°C but these two dissimilar metals give very good welding strength. The weld pieces are subjected to compression test and it is proved the welding strength is good. The metals are welded at an r.p.m of at 1500 .
Figure 1: Working principle of heat pipe (copy from Electronics Cooling Magazine) As shown in the Figure 1, the heat pipe in its simplest configuration is a closed, evacuated cylindrical vessel . Its internal walls are lined with a capillary structure also called a wick. It is saturated with a working fluid. The heat pipe works on the principle of latent heat of evaporation and condensation of fluid at the
The absorbed intensity transformed into heat within the penetration depth of laser radiation .And when the illuminated spot on the surface reaches the boiling temperature, material removal starts due to the process of vaporization. The material is heated by powerful light pulses of 10-4 to 10-3 seconds duration. The advantages are non-contact process, problem of wear broken drills, faster process, high precision and possibility of drilling hard material. These techniques are used in perforation in plastic, nozzles and nylon buttons, aircraft engine turbine blade etc. Usually pulsed carbon dioxide and alexandrite lasers are used.
Welding Welding is an operation in which two or more parts or metals (similar or dis-similar) are united by means of pressure in such a way that there is continuity in the nature of the material (metal) between these parts. A filler metal, whose melting temperature is of the same order as that of the parent material, may or may not be used. (welding) Classification of Welding: Fig. 1.1 classification of welding processes Friction stir welding Introduction: Friction stir welding is a solid state welding. It is the process of joining of metallic components of similar or dis-similar material with the help of a cylindrical rotating tool.