Closed Recycling Process for Metal Matrix Composite Materials

开发了铝基复合材料低品位废料密闭回收工艺。水溶性卤化物熔剂处理是该工艺的关键技术。从基体、增强体和熔剂的分离回收角度探讨了熔剂处理条件，采用NaCl-KCl-KF体系熔剂可从Al-SiC复合材料的废料中分别回收铝合金和SiC颗粒。少量KF（KF < 1质量%）即可达到较好的效果，回收的铝合金可循环用于各种用途。由于Al_2O_3和K_2NaAlF_6的共存，回收的SiC颗粒不能再用作增强体。有必要消除污染或找到其他用途。在此基础上，提出了回收工艺流程。

Closed recycling process for low-grade scrap of Al-based composite materials was developed. Flux treatment with water-soluble halide is a key technique in this process. In the present work, flux treatment conditions were discussed from the viewpoints of separation and recovery of base material, reinforcement and flux.The aluminum alloy and the SiC particulate can be recovered separately from the scraping waste of the Al-SiC composite material by using the flux of the NaCl-KCl-KF system. Only small amount of KF is enough to achieve a good result (KF < 1 mass%).The recovered aluminum alloy can be recycled for various usages. Because of the coexistence of Al_2O_3 and K_2NaAlF_6, the recovered SiC particles cannot be reused as reinforcement. It is necessary to eliminate the contamination or to find the other uses. The recovered flux is reusable with supplemental addition of fluoride.Recycling process flow was proposed based on the present result.