On September 16, 2026, Zhu Yuntian, Editor-in-Chief of Materials Research Letters, released a special editor's recommendation focusing on multiple breakthroughs in additive manufacturing metal heterostructures. The content includes: heterogeneous layered structure design in additively manufactured titanium alloys achieving strength-ductility synergy (for biomedical implants), intermetallic-reinforced aluminum alloys with microstructural heterogeneity balancing room-temperature and high-temperature performance, physics-informed machine learning prediction of strength-plasticity in metastable β titanium alloys, reverse heterogeneous grain structure in TiVNbZr refractory high-entropy alloys, and a review of additive manufacturing of metal heterostructure materials from 1D to 4D. The heterostructure approach provides a new paradigm for 'ultra-high strength + high toughness' in as-printed metal powder parts, bridging the traditional strength-ductility trade-off contradiction of homogeneous materials. Developers of high-end powder grades (β titanium alloys, refractory high-entropy alloys, aluminum alloys) can use heterostructure design as a selling point for performance premiums in printed parts.