Microstructure and Mechanical Properties of Hot-Rolled ZrAl14Ti3 and ZrAl14Ti9 Alloys

This study systematically investigated the microstructure and mechanical properties of hot-rolled and quenched ZrAl14Ti3 and ZrAl14Ti9 (at.%) alloys. Microstructural analysis revealed that both alloys consisted of equiaxed α-Zr and Zr3Al grains. Increasing Ti content lowered the dissolution temperature of Zr3Al in α-Zr, enhancing the solubility of Al in α-Zr under identical thermal conditions and decreasing the Zr3Al phase fraction. Moreover, higher Ti content in the ZrAl14Ti9 alloy significantly promoted Zr3Al recrystallization and α-Zr globularization, leading to grain refinement and complete elimination of the α-Zr basal texture. Mechanical property evaluation showed that the ZrAl14Ti3 alloy exhibited offset yield and tensile strengths of 888 ± 12 MPa and 1056 ± 19 MPa, respectively, with a fracture elongation of 23 ± 1%. The ZrAl14Ti9 alloy displayed enhanced strength without compromising ductility, achieving a 110 MPa increase in offset yield strength (998 ± 6 MPa) while maintaining the same fracture elongation (23 ± 2%). The strengthening effects observed in the ZrAl14Ti9 alloy stemmed from multiple synergistic mechanisms: solid-solution strengthening due to increased Ti content in α-Zr, refinement of both Zr3Al and α-Zr grains, a higher proportion of the harder α-Zr phase, and orientation hardening resulting from the elimination of the α-Zr basal texture.