| 摘要 |
FIELD: physics, measurements. ^ SUBSTANCE: invention relates to analysis of material surface and can be used for revealing the boundary of surface-ageing plastic material brittled layer. To initiate formation of micro fractures in aged layer, the specimens are subjected to expansion at temperatures exceeding their brittleness temperature and lower then their glass transition temperature, if the specimens belong to amorphous plastics, or lower then their melting point, if they represent crystalline plastics. Since ageing processes occur, primarily, in surface layers that become brittle, aforesaid micro fractures get formed only in aged layer and propagate only to the boundary of non-aged layer due to its conserved ability to display viscoplastic properties. Thus, expansion of specimens from aged plastics at temperatures exceeding brittleness temperature and lower than glass transition or melting temperature, allows aged layer, depending upon the material type, to display itself completely in the fractured layer representing that with multiple equal-depth fractures. ^ EFFECT: higher accuracy of determining brittled layer boundary damaged by ageing. |
