Abstract
The mechanical properties of friction welded joints of AZ31 magnesium alloy to 1050 aluminum, which were made by a brake type friction welding machine, were examined by mechanical tests and optical micrograph. The burr on the welds occurres from 1050 aluminum, and its enveloped in AZ31 alloy at the weld zone regardless of the welding conditions. It is recognized that the original fibrous structures disappeared at near the weld interface. Both compound layer and mechanical mixing layer were observed on the weld zone. Hardness of the weld interface has a higher value than those of the base metal. The tensile strength of welded joints are improved with increasing the friction time. In case of the friction pressure 70MPa, the tensile strength of welded joints are slightly higher than that of the 1050 aluminum, but friction welded joints under the friction pressure of 50MPa and 60MPa are inferior to the 1050 aluminum. The elongation of all the welded joints are inferior to that of the AZ31 alloy. All the tensile specimens are fractured at the weld interface. The impact specimens in which notch is put into the weld interface show impact strength lower than that of the AZ31 alloy.
