Aluminum is common material used in the welding industry due to its suitable properties. Although aluminum welding generally has disadvantages. One of these weaknesses is the formation of porosity, which will affect the welded joint's mechanical properties. There are different welding methods such as electric arc welding, combustion, Electron Beam Welding, Friction Stir Welding and more. There are better welding methods and there are less and each method must be adapted to the appropriate material and product. In each of these welding methods, welding failures can occur such as porosity. porosity is formed due to two mechanisms, shrinkage porosity caused by shrinkage during the metal solidification process and gas porosity caused by air trapping and undissolved hydrogen. The welding process often produces gases such as hydrogen, carbon dioxide and steam. During welding, the metal goes into a liquid state and then cools at a rapid rate. because In a liquid there is a higher solubility of a gas than in a solid, This may trap gases inside the material and create bubbles when the welding takes place. this process called porosity. during the welding of die-casted parts, the hydrogen diffuses into the melt pool and causes porosity upon solidification.
porosity in welding is a weak, bubble-filled weld that does not meet code and more importantly can in some cases, cause part of a project to become weak and collapse. Porosity can cause cracks and corrosion, and it weakens the welded joint. Defects of porosity in welding can reduce toughness, reduce fatigue, reduce ductility in welded joints and cause changes in the microstructure, causing changes in the mechanical properties of welding results. To reduce porosity, it is important to use the right welding technique and the right welding materials. The welding process should be optimized to reduce the amount of hydrogen present in the weld. Proper cleaning of the base material and proper welding techniques can help reduce porosity. The use of shielding gases, such as argon, can also help reduce porosity. It is also important to ensure that the welding temperature.
To deal with the bubbles problem we will try to deal with preliminary problems:
1. The ability to control welding speed and the degree of solidification - when the welding speed is slow and it is not possible to control the degree of solidification, there is a chance of more gas bubbles that will be trapped inside the solid
2. Cleaning the welding area- Once in the welding area the chances of material failures are greater
3.Using the most efficient welding technique- When using a welding method that is not suitable for the material, the chances of getting welding failures are greater
Good control over the correct welding method which minimally damages the material due to heating in the area. Control on speed heating to prevent the shooting of gas bubbles.