Liquid metal assisted regulation of macro-/micro-structures and mechanical properties of nanoporous copper

Nanoporous metals have received significant attention as a new class of structural and functional materials.However,the macroscopic brittle fracture under the tensile test is an impediment to their practical applications.Thus,it is of central importance to develop nanoporous materials with low cost and high tensile ductility.Herein,a nanoporous Cu film supported on a pure Cu substrate(NPC@Cu)was fabricated by utilizing a liquid Ga assisted alloying-dealloying strategy,and the thickness of NPC film can be precisely regulated by changing the mass loading of liquid Ga.In-situ X-ray diffraction was performed to further explore the alloying/dealloying mechanisms.The NPC@Cu films show good tensile mechanical properties with a minimum elongation of 13.5%,which can be attributed to the good interface bonding and certain modulus matching between the nanoporous Cu layer and the Cu substrate.Our findings demonstrate that the design of film-substrate structure provides a feasible strategy for enhancing the mechanical properties of nanoporous metals.