Microstructure and interfacial characteristics of aluminium-diamond composite materials

This work reports about microstructure, morphology and interfacial characteristics of aluminium-based composites reinforced with micro- and nano-sized diamond particles. Composite samples were produced by pressurized liquid metal infiltration (squeeze casting) of tap-packed diamond powders, and studied by transmission electron microscopy (TEM) and Raman spectroscopy techniques. The micro-sized diamond particles were observed to be homogeneously dispersed and well bonded in the Al-matrix. However, the nano-sized diamond particles principally appear as large agglomerates in the Al-matrix, even though individual nano-sized diamonds are found to be finely dispersed in the Al-matrix too. The M-diamond interface is generally clean, i.e. devoid of reaction products. However, an interfacial amorphous disordered carbon layer is occasionally observed, and in the composite with the nano-sized diamonds aluminium carbide phases (A],C,) are randomly formed. (C) 2003 Elsevier B.V. All rights reserved.