抄録
In recent years, aluminum alloy became used for a lot of structure. With it the example which a welder method is used for about the connection is increased However, the welding of aluminum alloy is difficult And the possibility that welding defects is made in welding is high. Therefore, with the ultrasonic testing, welding defects must be detected Then, the existence or non-existence of welding defects and the size of welding defects must be estimated In this study, it inserted welding defects in the weld of aluminum alloy artificially. Then, it did an ultrasonic testing and tensile test about the weld joint which contains defects. And it examined the precision to estimate the size of welding defects and the influence which the flaw exerts on the strength. As a result it made the influence which welding defects exerts on the strength of the weld clear. It was possible to examine about it and the estimated precisicn that ultrasonic testing estimates defects.
