Tensile Test of Notched Thin Film of Pure Titanium Actuated by Thermal Stress

Tensile tests of notched thin film of pure titanium were carried out on the stage of a digital microscope. Tensile load was generated by the thermal expansion of a pair of polycarbonate loading plates by which the specimen was sandwiched. Since the thermal expansion coefficient of polycarbonate is much larger than that of pure titanium, the specimen was elongated with an increase in the temperature and successfully fractured at the end of the tensile test. The plastic deformation of the notched part of specimen was observed during the test and the stress and strain were evaluated. The obtained stress-strain curve situated between two curves by a commercial tensile testing machine at the room temperature and at 363 K, which approximately corresponds to the maximum temperature of the thermal stress-actuated tensile test. As the mechanism of the proposed tensile test is simple, it is expected to be applicable to much smaller specimens in the future.