Development of the 'Super-Dimpler' for preparation of a thin specimen for TEM observations of the machined surfaces.

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In observation using, transmission electron microscope(TEM), we spent a lot of time to prepare thin film specimens, for they must be thin enourgh to be transmitted by electron beam and their surfaces need to be flat. Especially ceramics is usually chemically stable, so tfiat the ion-thinninc, method is used for making, its TEM specimens. However, this method has many problems, such as a damaging and rouaheriing at the surface by the ion beam attackin.In this research, we make on an experimental basis a auto-polishin, machine with submicron position control mechanism and establish a preparation technolooy of damage-free specimen for TEM observation only by mechanical thinninal thinning.First of all, surface damage, e morpholo, , y produced by some conventional thinning methods (ariseding, polishing with diamond abrasive, and polishing by a dimpler) are estimated usincr TEM. Both the ground surface and the dimpler polished surface has severe residual stress with a crack both in grains and grain boundaries. And the diamond polished surface has many scratches. Therefore these methods are not suitable for makinc, TEM specimens.Then, a 'Super Dimpler' using a new concept on basis of the strain-free mechanochemical polishincr is designed and developed. Its processing mechanism is followed ; A disk rotating, at above 10^4 rpm in a polishing solution is approached to a specimen with keeping them apart. Abrasive in solution flowing between the disk and the specimen at high speed polish the specimen surface.Polishing with alumina abrasive showed that removine, proceeded in the non-contact state. This means that the dimple pattem processing, using mechanochemical polishing, is available. For the future, we can prepare thin film specimens for TEM observations which have no surface damage at short processing, time.