Embrittlement of TiZr null-matrix alloy by deuterium

Full text: Ti2.1Zr is a popular material for constructing experimental cells for neutron diffraction experiments in which the sample is subjected to fluid pressure. We studied the embrittlement of Ti2.1Zr under deuterium pressures of 600-700 bar at temperatures up to 200degC. At temperatures up to 75degC the alloy survived two weeks of immersion in 650 bar D2 with no significant loss of ultimate tensile strength. At 100degC, however, embrittlement was observed under the same conditions, and at 200degC rapid decrepitation to a coarse powder occurred. Neutron powder diffraction indicated that the products included TiD2. We conclude that Ti2.1Zr is not safe for use with deuterium gas above room temperature. (authors)