Tensile testing of thin films -the development of a method of mounting thin film specimens-

摘要

A new mounting method of thin film specimens on a tensile machine has been developed in order to conduct tensile tests of thin films. The test section of thin film specimens was 0.3 mm in width and 1.4 mm in gauge length. The thin film specimenswere gripped by the newly developed mechanical gripping device using a micrometer at a pressure of about 1 MPa. The new gripping method makes the specimen easy to mount on the tensile machine. As the results, mechanical properties of titanium thin filmsof 0.50μm thickness, formed by magnetron sputtering, were successfully measured. That is, the thin film specimens fractured at the test section, but not at the grip section. The stress-strain diagrams of thin films were measured continuously at roomtemperature in the atmosphere at a loading speed of 0.8μm per second. The experimental results indicated that the titanium thin films had a small breaking elongation of about 2% although they had a large tensile strength of about 1 GPa. The fracture mode of the specimens was mostly due to brittleness with less plastic deformation.