Shear compaction processing of SiC nanoparticles reinforced magnesium composites directly from magnesium chips

In this work, a novel synthesis technique, shear compaction processing (SCP), is developed to produce magnesium (Mg) based composite from Mg machining chips and nano-sized silicon carbide (SiC) particulates reinforcement. During the process, Mg machining chips are first loaded into the container and slightly compacted, and then SiC nanoparticles are added on top of the compacted Mg chips. A scroll faced rotating tool with a designated diameter is plunged into the Mg chips at a selected spindle rotation speed and feed rate. Due to the huge amounts of heat generation, the softened materials are compressed and synthesized to form a nanocomposite disk eventually. The results show that the SCP process is a feasible solution for producing a void-free bulk nanocomposite material directly from Mg chips and SiC nanoparticles in a single step. The microstructural analysis with optical microscopy and scanning electron microscopy clearly shows the significant grain refinement in the produced nanocomposite disk. The reinforcement of nanoparticles is uniformly distributed in the mixed domain. Good interfacial bonding is captured between the matrix and SiC nanoparticles. The produced specimen has a higher hardness than the parent material, and also exhibits excellent wear resistance. The significant improvement is attributed to the resulting fine-grained microstructure and homogenous distribution of SiC nanoparticles throughout the matrix material of Mg, due to severe plastic deformation and mixing during the SCP process. (C) 2016 The Society of Manufacturing Engineers. Published by Elsevier Ltd. All rights reserved.