Microstructure and mechanical properties of hot-rolled Zr–3Al–χBe alloys

The effects of beryllium (Be) addition on the microstructure and mechanical properties of hot-rolled Zr–3Al–χBe alloys (χ=0, 0.4, 0.6, and 0.8 wt%) were characterized experimentally. X-ray diffraction and optical microscopic results indicated that the complete α phase was replaced by α phase+Be2Zr compound in the alloys after Be addition. Meanwhile, with an increase of Be content from 0.4 wt% to 0.8 wt%, the content of Be2Zr particles increased in the examined Zr–3Al–χBe alloys. Moreover, partial α recrystallization was observed in the hot-rolled Zr–3Al alloy. The degree of α recrystallization tended to increase in the alloys with Be addition. Adding Be is beneficial to the improvement of the tensile properties. The Zr–3Al–0.8Be alloy exhibited maximum ultimate tensile strength of 1103 MPa, which increased by 27% compared with that of the hot-rolled Zr–3Al alloy and the elongation remained at 6.07%. Fractography results indicated that the fracture modes of the Zr–3Al–χBe alloys transformed from ductile to a combination of ductile and brittle with the gradual addition of Be.