The phase relations and hydrogenation behavior of Sr1-xBaxAl2 (0≤x≤0.5) alloys have been studied. It was found that the maximum solubility of Ba in the Zintl phase SrAl2was about x=0.082. When x=0.082∼0.156, the alloys consisted of the Zintl phase, (Ba,Sr)7Al13 and (Sr,Ba)Al4. When x≥0.156, the Zintl phase disappeared and (Ba,Sr)7Al13 and (Sr,Ba)Al4 remained. Under a hydrogen pressure of 7 MPa, the Zintl phase (Sr,Ba)Al2 was first hydrogenated to (Sr,Ba)Al2H2 and then it disproportionated into an unknown hydride and Al. In the disproportionation course, an amorphous hydride was formed as an intermediate phase. (Ba,Sr)7Al13 was first hydrogenated into an amorphous hydride and then (Sr,Ba)Al4 crystallized in the amorphous matrix. The amorphous hydride also transformed into the crystalline unknown hydride and Al when the hydrogenation temperature further increased. Increasing Ba content led to a rise of the formation temperature of the unknown hydride.
All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry