Three-dimensional amorphous Ni−Cr alloy printing by electrochemical additive manufacturing

Amorphous metals have wide applications, including those in various transducer and sensor devices, because of their extraordinary physical and chemical characteristics, excellent mechanical properties, and corrosion resistance. However, their intrinsic ultrahigh strength and frangibility limit their manufacturing. Herein, a microanode-guided electroplating (MAGE) method is introduced to fabricate three-dimensional microhelices of amorphous Ni−Cr alloys. In MAGE, a super-high strength electrical field (∼10⁵ V m⁻¹) was established by charging a few volts across a tiny electrode gap (approximately 100 μm). The current density of MAGE was 2 orders of magnitude higher than that of traditional thin-film electrochemical coating that undergoes kinetic control processes, favoring the amorphous phases. The morphology, composition, and physical properties of the micro Ni−Cr devices were also investigated, revealing the outstanding reduced Young’s modulus (165 GPa), hardness (8.21 GPa), and high-temperature Joule heating stability up to 1200 °C.