Aluminium Alloy Matrices Reinforced with Coated Particulate Silicon Carbide

The low-cost production and performance of 6061-aluminium alloy matrices reinforced with coated silicon carbide particulate has been studied. The micro-wave vacuum sintering was adopted to prepare the composite in order that the loss ignition is very small. The effect of copper coated silicon carbide has proved beneficial to interfacial bonding and improved the mechanical properties. Differences in the fracture characteristics of specimens containing coated and non-coated particles were observed. The particulates size has much influence on mechanical properties.

A Study of Residual Stresses in Al/SiCp Linear Friction Weldment by Energy-Dispersive Neutron Diffraction

Linear friction welding (LFW) is a solid state joining process for bonding of two flatedged, complex geometry components through relative reciprocating motion under axial (compressive) forces. Although the proof of principle has been obtained some time ago, recently a number of studies have been published aimed at optimising the joining operations to obtain best joint strength and reduced distortion and residual stress. The present paper is devoted to the study of linear friction welds between components made from aluminium alloy 2124 matrix composite (AMC) reinforced with 25vol% particulate silicon carbide (SiCp). Neutron diffraction was used to measure interplanar lattice spacings in the matrix and reinforcement, and to deduce residual elastic strains and stresses as a function of distance from the bond line. Significant asymmetry is observed in the residual stress distribution within the two components being joined, that may be associated with the difference in the microstructure and texture.

Internal Stress Development during Fatigue Cycling of High-Strength Al/SiC Metal Matrix Composites

In this paper, results are presented of the development of internal stresses in 2124 aluminium alloy reinforced with 25% of particulate silicon carbide. Measurements have been made during in situ low-cycle fatigue loading of this composite, using neutron diffraction. The neutron measurements were made using the ENGIN-X diffractometer at the ISIS neutron facility, UK. The results show how the internal stresses evolve with fatigue cycling. Eshelby-based modelling has been used to allow separation of the internal stress components in the MMC.

Processing and Characterization of Particulate SiC Reinforced Copper Matrix Composites

Copper Matrix Composites reinforced with particulate Silicon Carbide were consolidated by Vacuum Hot Pressing and Press-Sinter routes. The reinforcement content was varied from 10% to 30% by volume. The composites were then characterized for their microstructure, density, X-ray diffraction (XRD), Coefficient of Thermal Expansion (CTE), hardness, tensile strength, electrical conductivity and elastic modulus. The properties were compared with those of Copper Tungsten alloys. Cu/SiC composites are found to be potential materials for electrical contact and welding applications. An attempt has also been made to evaluate the suitability of copper matrix composites as a replacement to copper tungsten alloys.