Abstract: It is found that coated spacecraft interfaces separate unsuccessfully despite without cold welding during the spacecraft manufacturing.To investigate the mechanism, effective factors and protection scheme of the phenomenon an experiment was carried on. In this experiment, the aluminium alloys blocks which were coated with nothing, colorless oxidation, MoS₂, bright gold plating, and white anodic film respectively were pressed together in pairs, and placed in a high vacuum tank immovably for a period of time. And the separating force between the blocks was tested outside the immovably high vacuum tank. If the experimental blocks were separated unsuccessfully, new copies were placed immovably in the natural pressure and several different temperatures for a period of time.Then the separating force was tested, and the shape changing and element transfering conditions of the interfaces were analyzed. The experiment result shows that there′s much tiny concavo-convex grain in the interface of the blocks. Because of the interlocked grain, the blocks have separated unsuccessfully. Hardness and roughness of coating is the immediate cause of this phenomenon,which is called physical tabling. For immovable spacecraft interfaces, a protection method that the coating should be harder and smoother was proposed and validated.

Key words: Interface, Physicaltabling, Mechanism, Protection, Spacecraft