A lap joint of A5083 aluminum alloy and SS400 steel was produced by Friction Stir Welding (FSW) using the various process parameters such as rotational speed, traverse speed and pin depth. The variations of welding parameters produced various characteristic interfaces and had conspicuous influences on the joint properties. Increasing the rotational speed decreased the shear load of the joint due to producing a thick FeAl 3 intermetallic compound (IMC) at the interface. When traverse speed increased, the shear load increased because IMC thickness at the interface decreased, however, when the speed was so high, an incomplete interface was formed. Increasing the pin depth produced a thick FeAl 3 IMC phase and an incomplete interface that directly deteriorated the shear load of the joint.

This paper investigated the effect of a tilt angle and a pin diameter of the tool on the tensile shear load of lap joints between A5083 aluminum alloy and SS400 steel produced by Friction Stir Welding. The main results obtained are as follows:The joint shear strength could not be increased with the increase of a tool tilt angle due to the formation of intermetallic compound at the joint interface. The increase of a tool tilt angle caused the concentration of aluminum in the intermetallic compound increased, resulting in the decrease of the joint strength. The increase of a pin diameter of a tool also could not increase the shear strength of the joint due to a void defect and a thicker intermetallic compound formed at the interface. The size of the void increased as the pin diameter increased. The effect of a prehole, which was opened at the pin inserting position of an aluminum plate before welding, was investigated to obtain the higher shear strength of the joints. It was concluded that the joint interface temperature was slightly decreased and the thickness of the intermetallic compound at the interface decreased with the increase of pre-hole diameter. The optimal pre-hole indicated the shear strength of about 77% that of the aluminum base material. The interface microstructure examination showed no intermetallic compound was formed at the joint interface.

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This research aims to study the effects of various welding parameters in gas metal

A shielded metal arc welding (SMAW) using various covered electrodes applied to produce a hard-faced weld metal on FC25 gray cast iron bare surface. It found that all welding parameters such as 3 electrode types and welding currents of 90-130 A were able to produce a sound weld metal without a defect that could deteriorate the joint strength. The white cast layer thickness that was formed at the interface between the weld metal and the base metal was increased when increasing in the welding current and the alloying element in the electrode. Impact strength tended to increase when the alloying element such as chromium (Cr), molybdenum (Mo), and manganese (Mn) was existed, and it showed the maximum impact strength when H600 electrode was applied. In a comparison of microstructure characteristics of the joints, the joint that showed the maximum impact strength had the formation of fine needle-like grain in the weld.