Huiyuan Wang

Manufacture of Nano-Sized Particle-Reinforced Metal Matrix Composites: A Review

AbstractCompared to the micro-sized particle-reinforced metal matrix composites, the nano-sized particle-reinforced metal matrix ncomposites possess superior strength, ductility, and wear resistance, and they also exhibit good elevated temperature properties. Therefore, the nano-sized particle-reinforced metal matrix composites are the new potential material which could be applied in many industry fields. At present, the nano-sized particle-reinforced metal matrix composites could be manufactured by many methods. Different kinds of metals, predominantly Al, Mg, and Cu, have been employed for the production of composites reinforced by nano-sized ceramic particles such as carbides, nitrides, and oxides. The main drawbacks of these synthesis methods are the agglomeration of the nano-sized particles and the poor interface between the particles and the metal matrix. This work is aimed at reviewing the ex situ and in situ manufacturing techniques. Moreover, the distinction between the two methods is discussed in some detail. It was agreed that the in situ manufacturing technique is a promising method to fabricate the nano-sized particle-reinforced metal matrix composites.

Influence of melt superheating on microstructures of Mg-3.5Si-1Al alloys

The influence of melt superheating treatment on the microstructures of Mg-3.5Si-1Al alloys unmodified and modified with 0.2% Sr-Sb (mass fraction) was investigated. The results show that when the melt superheating temperature increases from 750 to 900℃, the average size of primary Mg2Si in the unmodified alloys decreases progressively from about 27 to about 19μm, while that in Sr-Sb-modified alloys. As refined considerably from about 14 to about 7μm when the temperature increases from 750 to 850℃, and then slightly increases to about 9μm with temperature further increasing to 900℃, which might be attributed to the burning loss of Sr and Sb in melts. However, the superheating temperature only has a slight effect on the morphologies of both primary and eutectic Mg2Si phases in unmodified and Sr-Sb-modified alloys.