Abstract: Disclosed are a silicon nitride ceramic sintered body and a preparation method thereof. The silicon nitride ceramic sintered body has a content of a silicon nitride crystalline phase of not less than 98 wt %, a relative density of not less than 99%, a porosity of not larger than 1%, a grain boundary phase including Li, O, N, and Si elements, and a total content of C, F, Al, Mg, K, Ca, Na and rare-earth metals elements of less than 0.1 wt %.

Abstract: The present disclosure discloses a preparation method of a multi-functional marine engineering alloy. Through the coupling of a multi-principal alloy structure, structural entropy, and temperature and powder metallurgy and heat treatment, mutual solubility between elements and free energy of an alloy system are regulated, Cu grain boundary segregation is eliminated, and uniform and dispersed nano-precipitation of the anti-fouling element Cu in corrosion-resistant and high-plasticity multi-principal alloys is realized. The preparation method is simple and controllable to operate, and the prepared material has plasticity higher than 75%, high yield strength, excellent corrosion resistance and anti-fouling property, and has important application prospects in the field of marine engineering.

Abstract: The present disclosure provides a method for modifying a hydrogel lubricating coating on a surface of general equipment, and hydrogel lubricating coating-modified general equipment, belonging to the technical field of material surface modification. In the present disclosure, by combining catechol adhesion chemistry and free radical polymerization initiated by surface catalysis, the method can realize in-situ generation of free radicals at an interface of a substrate and a hydrogel monomer solution at room temperature, without external auxiliary conditions such as illumination or heating. The method can prepare the hydrophilic hydrogel lubricating coating on the surface of almost all existing substrates, which is especially suitable for lubricating modification on an inner surface of a non-translucent pipeline instrument, showing material versatility. Therefore, the method is suitable for the fields of surface engineering and biomedicine.

Abstract: The present disclosure discloses a preparation method of a multi-functional marine engineering alloy. Through the coupling of a multi-principal alloy structure, structural entropy, and temperature and powder metallurgy and heat treatment, mutual solubility between elements and free energy of an alloy system are regulated, Cu grain boundary segregation is eliminated, and uniform and dispersed nano-precipitation of the anti-fouling element Cu in corrosion-resistant and high-plasticity multi-principal alloys is realized. The preparation method is simple and controllable to operate, and the prepared material has plasticity higher than 75%, high yield strength, excellent corrosion resistance and anti-fouling property, and has important application prospects in the field of marine engineering.