On the effect of the nature and physical state of a polymer support on the stress-strain characteristics of metallic coatings

A newly proposed microscopic procedure makes it possible to estimate the strength of thin (nano-metric) coatings deposited onto various polymer supports. The strength of the deposited coating is shown to increase dramatically when the thickness of the coating decreases below 15 nm. It was also found that the strength of the coatings is controlled by the physical state of the polymer support. The Interfacial layer formed at the early stages of metal deposition onto the polymer surface is characterized by a higher strength as compared with that of a pure metal deposited onto the above interfacial layer. This observation can be explained by the following reasons: first, the dimensions of metallic grains in the interfacial layer are much smaller than those in a pure metal and, second, the intergrain space in the interfacial layer is filled with polymer matrix. At the same time, both the temperature and the adsorptionally active liquid medium affect polymer partitions in the interfacial composite layer and thus control the overall strength of thin coatings (≤15 nm). In the case of thicker coatings, the strength of the coating gradually decreases independently of the nature and state of the supporting polymer and approaches the strength of the bulk metal.