3D打印FeCoNiAlTi高熵合金的高温力学性能研究OA

Ships operating long-term in marine environments are exposed to complex,variable and highly challenging external conditions including high stress,severe corrosion and wide temperature fluctuations,thus imposing higher requirements on the mechanical properties of materials.Additive manufacturing technology enables the fabrication of metal structural components with both high precision and high fatigue strength,providing a new technical approach for material applications under extreme environments.As a promising new alloy system,high-entropy alloys(HEAs)have attracted extensive attention due to their excellent mechanical properties even under extreme conditions.FeCoNiAlTi high-entropy alloy is a typical FCC-type alloy system;additive manufacturing technology can be used to construct multiscale microstructures to enhance its performance.Based on this,bulk(FeCoNi)86Al7Ti7 materials were printed via selective laser melting(SLM)technology,and the tensile mechanical properties and microstructural evolution of the alloy from room temperature to 730℃ were systematically investigated.The results show that with the increase of temperature,the yield strength and ultimate tensile strength exhibit a significant downward trend,while the elongation decreases synchronously.The material demonstrates excellent comprehensive mechanical properties at room temperature,with a yield strength exceeding 680MPa,an ultimate tensile strength of approximately 924MPa,and a uniform elongation of up to 35％.When the temperature rises to 730℃,dynamic recrystallization induced by high-temperature stress leads to a rapid drop in strength to 171MPa and a reduction in uniform elongation to 11.06％.This study provides an important reference for regulating the high-temperature mechanical properties of high-entropy alloys under extreme conditions and offers guiding significance for developing new applications of high-temperature alloys.