1995 Volume 59 Issue 3 Pages 296-302
An equipment has been developed for detection of gasses evolved from metallic materials during deformation. It consists of a tensile-compression fatigue testing machine, a quadrupole mass spectrometer and an ultra high vacuum chamber which is evacuated to a vacuum of about 1.0×10−7 Pa with a tandem turbo molecular pump and a non-evaporable getter pump. Tensile tests have been carried out in the chamber for various metallic materials: an Al-5%Mg alloy, a 7005 aluminum alloy, an oxygen free copper, a Ti-6%Al-4%V alloy, a Cr-Mo steel, a Ti-48%Al alloy and some sintered materials and evolved gasses are analyzed by the quadrupole mass spectrometer connected to the chamber. Hydrogen gas has been evolved from all these materials during fracture even when impurity hydrogen is as low as a few ppm. This fact means that impurity hydrogen has been concentrated during deformation to the area where fracture will occur. In addition, other gasses were also detected during fracture, and the amounts of these gasses were lower than that of hydrogen.
