High-temperature tensile creep property of an additively manufactured Al-Ce-Ni alloy

A near-eutectic Al-Ce-Ni alloy inoculated with Ti/Zr was fabricated via laser powder bed fusion (LPBF), exhibiting promising printability and thermal stability. This work systematically investigates its tensile creep behavior and microstructural evolution at 300–400°C under stresses of 55–75 MPa. The alloy demonstrates remarkable creep resistance, primarily due to the thermally stable Al-Ce-Ni eutectic network that effectively hinders dislocation motions. Microstructural analysis reveals that the eutectic structure remains largely continuous during creep at 300°C, whereas it progressively fragments into fine dispersoids at higher temperatures. The microstructural variation drives a mechanistic transition from diffusion-mediated creep at lower temperatures to threshold-stress-controlled dislocation creep at 400°C. Correspondingly, the apparent stress exponent ( n app ) increases from ∼ 1.51 at 300°C to ∼ 8.39 at 400°C, and the apparent activation energy ( Q app ) ranges from 171 to 230 kJ·mol −1 . Threshold-stress analysis further confirms the strong obstruction of second-phase particles, yielding values of 29.3 MPa at 350°C and 28.2 MPa at 400°C.