Exact reversiblity in joining and separation

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For the purpose of the zero-emission world or the recycle of materials, the exact reversiblity is examined in the processes in Joining and Separation. A force measurement system constructed in ultra high vacuum chamber of Auger electron spectroscope is used. A piezo device actuator system is introduced in it and control software is programed by Visual C++. Experiments were carried out in the elastic range. After the measurements of adhesion forces, surfaces were observed by scanning electron microscope (SEM) and scannning Auger microscope (SAM). Although the atomic transfer between contacting samples was sometimes observed, there are some cases no transfer could observed by SAM. These results suggest the existence of exact reversible processes in Joining and Separation. The results are discussed with the continuum theory and the numerical analysis using molecular mechanics theory. Theoretical strength of adhered object can be deduced by continuum theory. Except for the limit when the size of atoms are negligible, molecular mechanics becomes significant. The modified embedded atom method (MEAM) which is made for the bulk is found to have applicability to surface problems.