Achieving ultrahigh fatigue resistance in AlSi10Mg alloy by additive manufacturing

C. Dan; Y. Cui; Y. Wu; Z. Chen; H. Liu; G. Ji; Y. Xiao; H. Chen; M. Wang; J. Liu; L. Wang; Y. Li; A. Addad; Y. Zhou; S. Ma; Q. Shi; H. Wang; J. Lu

Nature Materials (2023)

Since the first discovery of the fatigue phenomenon in the late 1830s, efforts to fight against fatigue failure have continued. Here we report a fatigue resistance phenomenon in nano-TiB2-decorated AlSi10Mg enabled by additive manufacturing. This fatigue resistance mechanism benefits from the three-dimensional dual-phase cellular nanostructure, which acts as a strong volumetric nanocage to prevent localized damage accumulation, thus inhibiting fatigue crack initiation. The intrinsic fatigue strength limit of nano-TiB2-decorated AlSi10Mg was proven to be close to its tensile strength through the in situ fatigue tests of a defect-free microsample. To demonstrate the practical applicability of this mechanism, printed bulk nano-TiB2-decorated AlSi10Mg achieved fatigue resistance more than double those of other additive manufacturing Al alloys and surpassed those of high-strength wrought Al alloys. This strategy of additive-manufacturing-assisted nanostructure engineering can be extended to the development of other dual-phase fatigue-resistant metals.