Synthesis Zr-Co-Y based chemical getter and evaluation its vacuum preserving, sorption characteristics, and hydrogen absorption

Abstract

In this research, a Zr-Co based chemical non-evaporable getter (NEG) was synthesized via mechanical alloying. A mixture with a 75 %Wt. Zr, 22 %Wt. Co, and 3 %Wt. Y composition (Zr75Co22Y3) was selected, mixed, and milled up to 42 h. The obtained powder was pressed in a tablet form. The sample was placed in a well-sealed vacuum chamber that was evacuated to 1.5×10^-5 mmHg. Then, the sample was subjected to different heat treatments (at various temperatures and times) for activation. Results revealed that the final vacuum for the Y36030 sample (Zr75Co22Y3 activated at 360ºC for 30 min) and the Y28030 sample (Zr75Co22Y3 activated at 280 ⁰C for 30 min) were 5.95×10^-6 and 9.9×10^-6 mmHg, respectively. After finishing the heat treatment, vacuum variation versus time was recorded in the range of 0.001-0.2 mmHg, the time for Y36030, Y28030, and a no-getter was 3088, 510, and 345 seconds, respectively. Sievert results showed that Y36030 absorbed 1.5 %Wt H₂ at 45 bar while Y28030 absorbed 1.05 %Wt. H₂. After removing the pressure, the remaining amount of hydrogen for Y36030 and Y28030 was 0.7 and 0.55 %Wt., respectively.