Abstract
Clearance at the interface of two solids in contact should be evaluated for sealing gas leakage. In this study, first of all, we designed experimental apparatus. It enabled us to detect the gas leakage in the sensitivity of 1.0×(10)^<-8>(Pa・m^3/s), which is equivalent to the clearance of 10∿50nm. Next, the relation of gas leakage with the experimental parameters such as surface roughness of interface, contact pressure, vacuum pressure, etc. were measured for the purpose that micro-space at the interface should be investigated. Namely, we tried to estimate the micro-space quantitatively based on the relation between the clearance at the interface of two solids metals in contact and their surface roughness. As a result, it becomes clear that qualitatively theoretical characteristics correspond comparatively well with experimental ones. However, the analytical values don't agree quantitatively with the experimental ones, approximately doubled. It would be caused by pressing down of tops and rising up of the valleys of the surface roughness due to plastic deformation of asperities in contact.
