AZ61 magnesium alloy plate with 0.6 mm thickness was the lap welded by friction welding using a rotating disk. Microstructure and mechanical properties of the welded joint were investigated. Two kinds of welding method which are up-welding and down-welding were done. In case of welding direction the same as rotational direction of rotating disk is called up-welding. And, opposite case is called down-welding. As for the joint surface of the upwelded joint, a scale-shaped pattern was observed. A reticulate pattern and the unevenness by the deposit were observed on the joint surface of the down-welding. In the vicinity of weld interface of both joints showed fine structure in comparison with base metal. And, oxide film was not recognized in some sections of the weld interface. The hardness of the welded zone softened slightly in comparison with base metal. The tensile shear load of the down-welded joints showed higher than that of the up-welded joints. The maximum tensile shear load of welded joint was 2.4 kN provided in welding speed V=4 mm/s of the down-welding.

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It is known in aluminum alloy sheets that two ears on a cup formed by deep drawing in 0° and 180° to the rolling direction may grow up by cold rolling. In the previous reports, Goss and RD rotated cube textures were fingered as the cause of the 0°/180° earing. But the growth process of the 0°/180° earing is not clear. In the present work, texture analysis has been carried out in cold rolling process with AA 6016 aluminum alloy sheets that have a strong cube texture through the thickness and Goss texture at the center layer. RD rotated cube texture is formed at the surface layer by cold rolling whereas cube texture at the center layer decreases rapidly. It is indicated that RD rotated cube texture at the surface layer and persisting Goss texture at the center layer cause high 0°/180° earing. These texture factors are discussed by a crystal plasticity finite element analysis.

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Detection of solidification cracking of JIS AC7A aluminum alloy and Al–7%Si alloy was attempted by using acoustic emission method. In order to detect AE of solidification cracking, we investigated about AE signals of gas porosity, shrinkage cavity, and fracture in the semi-solid tensile test. The frequency bands of these casting defects were 150 kHz or less, so the source characterization of AE signals were difficult by that. Therefore we discussed and suggested value of integrated AE peak volt as an indicator of crack initiation. As a result, we proved value of time integral (IAP) is beneficial for eutectic alloy and value of temperature integral (TIAP) is beneficial for noneutectic alloy. We also suggested value of time temperature integral (DIAP) as the criterion of crack initiation which is beneficial for eutectic and non-eutectic alloy.

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Friction aided deep drawing has been investigated to confirm the possibility of the deep drawing of square cups. A blank holder is divided into eight segments and these segments are used instead of the conventional blank holder. These segments of the blank holder can move radically inwards and outwards depending on the blank holding pressure. When an axially punch is used together with this deep drawing process, the drawing force decreases and also the shape and dimensional accuracy can be improved. In the square deep drawing, the deformation aspect varies from portion to portion; at the punch corner and at the straight flange portion. Experimental results show that the metal flow at the corner and at the straight f1ange portion is approximately uniform. The square cups of 60 mm height, which is 2.3 times of the side length, can be obtained from a circular blank of 120 mm diameter and 0.5 mm thickness. The number of moment of radial direction of the blank holding segments was 44 times.

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