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This presentation aims to introduce new approaches being made by Explosion Processing Group in the Institute of Pulsed Power Science,Kumamoto University,trying to find out new applications of the explosive welding technique.Two major approaches are demonstrated.One important method developed by the group is "underwater explosive welding technique" which renders it possible to weld various difficult-to-weld materials [1-6] under controlled energetic condition.Encouraging positive results have been confirmed for various hard materials such as ceramics,tool steel,rapidly solidified foil,tungsten sheet and others.Besides,the method is also good to weld magnesium alloy and other materials,which may cause melting or reactions easily.By using the method,the final surface facade of the welded surface is kept clean and the method is considered beneficial for the welding of thin plate-which is generally considered difficult to weld by conventional explosive welding technique.The other recent approach is the making of unidirectional pored structure(UniPore)through explosive welding using well known cylindrical geometry.The process is simple and executed by using many small pipes inserted solid paraffin.The small pipes are filled in an outer pipe,and the pipe was compressed by the detonation of an explosive placed outside of the outer pipe.The recovered samples showed quite uniform pored structure,and each channel was isolated by the wall of the small pipes welded tightly to each other even by using a thin pipe whose thickness was only 0.2 mm [7-8].The mechanism of the welding is considered to be achieved by the activation of thin metal surface(atomic order)by the metal jet between the small pipes,because jet trapped region was confirmed at the triple point of the small pipes.In the presentation,an alternative method making similar UniPore structure is demonstrated using rolled thin metal plate with spacers as well [9].These materials are expected to be applied for energy absorption material having un-isotropic mechanical property and for heat-exchanger or other related purposes.