(1. 南昌大学 材料科学与工程学院，南昌 330031；2. 南昌大学 机电工程学院，南昌 330037)
摘 要: 将剪切低温浇注半固态(LSPSF)浆料制备工艺与传统高压铸造工艺衔接，研究出一种半固态浆料直接成形工艺——流变压铸技术。结果表明：LSPSF工艺可在15~20 s制备出初生α(Al)形状因子为0.93，晶粒尺寸为70 μm且分布均匀，初生α(Al)内部没有夹裹液相的YL112铝合金半固态浆料；与传统压铸相比，流变压铸可改善YL112合金铸件的微观组织，半固态浆料在二次凝固中发生体积凝固，铸件微观组织细小且分布均匀。该LSPSF流变铸造工艺与传统压铸工艺衔接简便，半固态浆料输送平稳，具有较强的可操作性。
关键字: 流变成形；半固态；微观组织；压铸；YL112铝合金
（1. School of Materials Science and Engineering, Nanchang University, Nanchang 330031, China;2. School of Mechanical and Electronic Engineering, Nanchang University, Nanchang 330031, China）
Abstract:A new one-step semi-solid processing technique, the rheo-diecasting (RDC) process, was exploited, in which the independently developed low superheat pouring with a shear field (LSPSF) process was combined with the existing cold chamber high pressure diecasting (HPDC) process. The experimental results show that the LSPSF can prepare sound semi-solid secondary diecasting aluminum alloy YL112 slurry in 15−20 s to fully meet the production rate of HPDC, the primary α(Al) presents in mean equivalent diameter of 70 μm and shape factor of 0.93 and features zero-entrapped eutectic. Compared with conventional HPDC process, RDC process can improve microstructures in castings. Secondary solidification of semi-solid slurry takes place uniformly throughout the entire cavity and produces an extremely fine and uniform microstructure. The advantages of the present RDC process include easy incorporation into existing HPDC machine without infrastructure changes, smooth transportation of semi-solid slurry from the LSPSF machine to the shot chamber, high operability for pouring temperature and thermal control.
Key words: rheoforming; semi-solid; microstructure; diecasting; YL112 aluminum alloy
