低压铸造AlSi7Cu合金组织与性能调控研究综述

Research Review on Microstructure and Properties Regulation of AlSi7Cu Alloy in Low Pressure Casting

摘要: AlSi7Cu系铝合金是航空航天与汽车轻量化结构件的关键材料，低压铸造是其工业化主流成形工艺。本文系统梳理保压压力、冷却速度等核心参数对合金组织、致密度及力学性能的影响规律，从物理冶金角度分析凝固形核、生长、溶质分配与第二相演变机制，阐述电磁、振动、变质等复合改性工艺的强化原理，并整合数值模拟、机器学习、原位同步辐射成像、三维X射线显微镜等前沿技术应用进展。研究表明，提高保压压力可细化晶粒、球化共晶Si相、降低孔隙率，显著提升强韧性；冷却速度可调控组织均匀性，复合工艺能突破单一工艺局限，为工艺优化与工程应用提供参考。

Abstract: AlSi7Cu aluminum alloy is a key material for lightweight structural components in aerospace and automotive applications, and low-pressure casting is its mainstream industrial forming process. This paper systematically reviews the effects of key parameters such as holding pressure and cooling rate on the microstructure, density and mechanical properties of the alloy. The mechanisms of solidification nucleation, growth, solute distribution and second-phase evolution are analyzed from the perspective of physical metallurgy. The strengthening principles of composite modification processes including electromagnetic, vibration and modification treatments are discussed, and the application progress of advanced technologies such as numerical simulation, machine learning, in-situ synchrotron radiation imaging and three-dimensional X-ray microscopy is summarized. Studies show that increasing holding pressure refines grains, spheroidizes eutectic Si phase, reduces porosity and significantly improves strength and toughness. Cooling rate can regulate microstructure uniformity, and composite processes can break through the limitations of single processes, providing a reference for process optimization and engineering application.