The　challenge　of　fabricating　nanostructured　W–Cu　composites　by　powder　metallurgy　has　been　solved　by　means　of　modulated　phase　separation.　A　hierarchically　nanostructured　(HN)　W–Cu　composite　was　prepared　using　intermediary　Al　through　sluggish　asynchronous　phase　separation.　In　addition　to　a　dual　network　composed　of　a　Cu　phase　and　the　W–Cu　nanostructure,　dense　Al-containing　nanoprecipitates　with　a　body-centered　cubic　(bcc)　structure　are　distributed　in　the　W　matrix.　Compared　with　a　pristine　W/Cu　interface,　the　newly　formed　W/Cu　interfaces　modulated　by　Al　and　the　coherent　W/Al-containing　particle　interfaces　possess　lower　energy　and　enhanced　bonding　strength　due　to　efficient　electron　transfer　and　strong　coupling　interactions.　With　a　large　number　of　stable　heterogeneous　interfaces　and　a　“self-locking”　geometry,　the　HN　W–Cu　composite　exhibits　excellent　resistance　against　plastic　deformation.　The　combination　of　the　presented　composite＇s　hardness　and　compressive　strength　outperforms　all　other　sintered　W–Cu　composites　with　the　same　Cu　content.　Under　a　reciprocating　sliding　load,　the　reactive　Al　prevents　excessive　oxidation.　The　excellent　synergy　of　the　hardness　and　toughness　of　the　friction-induced　surface　endows　the　HN　composite　with　high　abrasion　resistance.　This　study　provides　a　new　strategy　to　modulate　the　structure　and　energy　state　of　interfaces　in　metallic　composites　containing　immiscible　components　in　order　to　achieve　high　mechanical　performance.　©　2023　THE　AUTHORS