Quick-mount grips: Towards an improved standard for uniaxial tensile testing of metallic superplastic sheets

摘要

It is the steady interest in the extraordinary ductility of superplastic materials that led to the launch of several standards on characterising their tensile behaviour, all within the past decade. However, those standards do not agree on many of the issues they cover, and fail to tackle some of the important and controversial issues in superplastic materials' testing; leaving the reader without adequate guidelines on those particular issues. In this work, a detailed review of the three main standards that describe the proper method for testing superplastic materials (JIS H7501, ASTM E2448 and BS ISO 20032) is carried out. The review focuses on the critical issues that significantly impact testing results, pointing out the points of agreement and disagreement among the three standards. And in an attempt to resolve some of those critical issues, an integrated testingrnmethodology centred about a unique set of quick-mounting grips that facilitates mounting and retrieving the test specimen in a very short time, is presented. The methodology promises resolving the majority of the aforementioned testing issues, and is hoped to provoke the development of a new more universally-accepted standard method for testing superplastic materials at elevated temperatures.