This paper describes an application of friction stir welding (FSW), solid phase welding, to fabricate railway car body made of aluminium hollow extrusions (double-skinned car body). The construction of double-skinned car body using FSW can reduce deformation and release process from skilled workers compared with the conventional method. In this paper, from the viewpoint of strength, we show our approach from a design of the joint's sectional shape to the final evaluation test using actual double-skinned car body fabricated by FSW. For design, reaction force in the workpiece coincident with heat input was considered. At load test, we evaluated stress levels at the joint, accuracy of the simulation of the car body and double-skinned car body's characteristics. As a result, railway car body joined by FSW can meet all the requirements for actual application. These benefits have been applied to 319 vehicles as of June 2002.
Because of rapidly decreasing line-width of integrated circuits, it is necessary to measure and control their critical dimensions with high accuracy. Hitachi has developed a new critical-dimension-measurement scanning electron microscope (CD-SEM) S-90(X) series, which has a new electron optics with retarding and boosting electric fields. The upper pole piece of the objective lens is kept at a high positive voltage with respect to the ground so as to reduce aberration of the objective lens drastically. To optimize the boosting voltage we have developed optics simulators that is capable of computing aberration coefficients in electric and magnetic mixed fields. At the optimized boosting voltage of around 5kV. 3nm resolution is achieved for a final accelerating voltage of 8(X)V. The high boosting voltage is effective in imaging bottoms of contact holes having high aspect ratios.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.