Accelerated testing of creep in polymeric materials using nanoindentation

Creep properties of polymers are conventionally obtained from tensile creep tests but, due to the different processing conditions used in their manufacture, the microstructure and properties of the specimens used in this type of test are often different to those found in actual components. This is particularly likely for micromouldings in which extreme processing conditions are experienced in their manufacture. Nanoindentation test procedures have, therefore, been developed to obtain creep properties directly from injection moulded components. This paper shows how creep data can be obtained from indentation experiments and how these tests can be accelerated by performing short-term indentation tests at elevated temperatures to predict long-term creep at ambient temperature. This technique can significantly reduce the length of time required to conduct indentation creep tests, allowing the creep properties of a polymer moulding to be mapped in less than a fifth of the time. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved.