Hydrogen absorption performance and mechanism of low-temperature activated Ti-Co-Ce bulk getter

Abstract

In this paper, a new type of non-evaporable low-temperature activated Ti-Co-Ce bulk getter was prepared. The phase structure, morphology and composition of this getter were studied by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) techniques, respectively. Under the activation condition of 350 °C for 30 min, its hydrogen absorption performance at room temperature was measured through the constant pressure method. The initial hydrogen pumping speed and cumulative absorption capacity within 2 h of Ti80Co15Ce5 (in the following, all alloy compositions, unless otherwise stated, are composition by weight) getter are 2700 ml/s·g and 4000 Pa·ml/g, respectively, which are more than twice those of Zr80.8Co14.2Ce5 (Zr-Co-Ce) and even greater than those of Zr70V24.6Fe5.4 (Zr-V-Fe) under the same preparation, activation and measurement conditions. XRD analysis shows that Ti-Co-Ce getter is mainly composed of (α-Ti) solid solution and Ti2Co intermetallic compound two phases. (α-Ti) instead of Ti2Co plays a more important role in hydrogen absorption. The hydrogen absorption performance of Ti-Co (Ti70.9Co29.1) getter even without rare earth addition is superior to Zr-Co-Ce, single Ti2Co or α-Ti phase. Measured by the constant volume method, the saturated hydrogen absorption capacity of 0.6 g Ti80Co15Ce5 is 143.6 Torr·L or 15.5 mg H2, higher than that of Zr-Co-Ce, intermetallic compounds Zr3Co and Ti2Co.