The layered ternary carbide Ti2SnC has outstanding mechanical and electrical properties. Therefore, the Cu matrix composite reinforced by Ti2SnC expects combined merits of both materials. In this article, we synthesized the copper matrix composites reinforced by Ti2SnC ceramic particles using hot-pressing method. The tribological behaviors of pure copper and composites reinforced with Ti2SnC were studied on a block-on-ring tester. The blocks were slid against 52100 steel rings under dry ambient conditions. It showed that the friction coefficient and wear rate of Cu matrix composites decreased significantly by incorporation of Ti2SnC particles. The wear rate of pure copper was about eight times that of the Cu-10 vol.% Ti2SnC composite under a sliding velocity of 20 m min(-1) and a normal load of 30 N. The satisfied low friction coefficient and wear resistance prove that Ti2SnC is a promising reinforcement material for Cu matrix composite. In addition, the effects of sliding velocity and normal load on wear behavior were investigated for pure copper and Cu-Ti2SnC composites. (c) 2006 Published by Elsevier B.V.

Tribological behavior of Ti2SnC particulate reinforced copper matrix composites

Spray forming combines the metallurgical processes of metal casting and powder metallurgy to fabricate metal products with enhanced properties. This book provides an introduction to the various modelling and simulation techniques employed in spray forming, and shows how they are applied in process analysis and development. The author begins by deriving and describing the main models. He then presents their application in the simulation of the key features of spray forming. Wherever possible he discusses theoretical results with reference to experimental data. Building on the features of metal spray forming, he also derives common characteristic modelling features that may be useful in the simulation of related spray processes. The book is aimed at researchers and engineers working in process technology, chemical engineering and materials science.

Spray Simulation: Modeling and Numerical Simulation of Sprayforming metals

Dispersion - strengthened nanocrystalline copper

Purpose: The objective of the work was to investigate changes in structure and properties of Cu – yttria microcomposites which take place in the process of controlled sintering and deformation of materials of nanometric initial structure Design/methodology/approach: Tests were made with the Cu-yttria micro-composites containing up to 3 % of a hardening phase These were obtained by powder metallurgy techniques and further deformation The mechanical properties and microstructure (by the optical, scanning and transmission electron microscopy) were examined Findings: Analysis of the initial nanocrystalline structure of these materials was made, and its evolution during deformation process was investigated with an account of the changes in the mechanical and electrical properties Research limitations/implications: The powder metallurgy techniques make it possible to obtain copper-based bulk materials Globular structure, high porosity and low sintering temperature of this materials result in their limited mechanical properties Practical implications: A growing trend to use new copper-based functional materials is observed recently world-wide Within this group of materials particular attention is drawn to dispersion hardened microcomposities with nanometric or submicron grain size of a copper matrix, which exhibit higher mechanical properties Originality/value: A controlled process of milling compacting, sintering and cold deformation, allow to obtain nanocrystalline copper based materials with improved functional properties

Microstructure and properties of nanocrystalline copper - yttria microcomposites

Purpose: The aim of this work was to determine the microstructure and properties stability of nanocrystalline copper dispersion hardened with nanoparticles of tungsten carbides. Design/methodology/approach: Tests were made with Cu and Cu – WC micro – composites containing up to 3% of a hardening phase. The materials were fabricated by powder metallurgy techniques, including milling of powders, followed by their compacting and sintering. The main mechanical properties of the materials were determined from the compression test, and, moreover, measurements of the HV hardness and electrical conductivity have been made. Analysis of the initial nanocrystalline structure of these materials was made and its evolution during sintering was investigated. Findings: It was found that an addition of up to 1.5 wt % of a WC significantly improves mechanical properties of the material and increases its softening point. Research limitations/implications: The powder metallurgy techniques make it possible to obtain nanocrystalline copper-based bulk materials. Additional operations of hot extrusion are also often used. There is some threat, however, that during high temperature processing or application these materials this nanometric structure may become unstable. Practical implications: A growing trend to use new copper-based functional materials is observed recently world-wide. Within this group of materials particular attention is drawn to those with nanometric grain size. Originality/value: The paper contributes to the determination of WC nanoparticles content on the mechanical properties and the nanostructure stability of Cu-WC micro-composites.

L. A. Nunez

Papers

Atomizers for molten metals: macroscopic phenomena and engineering aspects

Microstructure and Mechanical Behavior of Cu-Based Composites Reinforced with WC and TiC Particles, Prepared by Spray Forming