Multi‐Dimensional Design of Slippery Liquid‐Infused Coatings Empowering Long‐Term Corrosion Protection for Sintered Nd‐Fe‐B Magnets in Harsh Environments

Abstract In spite of superior magnetic properties, neodymium–iron–boron (Nd‐Fe‐B) applications in harsh environments have been greatly hindered by their susceptibility to corrosion, humidity, mechanical, and temperature attacks. Herein, a construction strategy of robust slippery liquid‐infused porous surfaces (SLIPS) coatings is proposed via the multi‐dimensional design of surface, bulk coating, and interface. The manipulation of colloidal states of silica particles by chemical hydrophobization allows for building a dense polymer network, enhancing interfacial adhesion and locking lubricant film effectively. The resulting coating is demonstrated to be extremely stable, endowing the magnet with excellent liquid repellency, anti‐corrosion, and anti‐icing properties. Strikingly, no trace of corrosion is detected after 136‐day immersion in 3.5 wt.% NaCl solution and the impedance modulus at 0.1 Hz can be maintained as the initial of 3.31 × 10 8 Ω·cm 2 even after 132‐day immersion, which is far superior to that of commercial Ni‐Cu‐Ni, Zn, and EP coatings. Additionally, anti‐icing performance at low temperatures is evidenced by the delayed icing time and decreased ice adhesion strength. Importantly, the self‐healing property offers the surface intensified durability even after mechanical damage. This work demonstrates a construction strategy of robust SLIPS coatings with a multi‐dimensional design, enabling the practical applications of Nd‐Fe‐B magnets in extreme environments like offshore wind turbines.