Papers by Keyword: Reinforced Aluminium

Abstract: Innovative composite extrusions consisting of an aluminium matrix material with steel fibres for reinforced lightweight constructions require adapted cutting technologies. Due to the resulting tool wear when machining such composite materials, new tools and processes have to be developed. The following article describes experimental investigations concerning conventional drilling operations in comparison to helix milling operations for the manufacturing of holes in these materials. Therefore especially wear and quality aspects are discussed. Furthermore a flexible cutting process for thin walled lightweight frame connector elements to combine profiles is described. To obtain detailed process knowledge also FEA-Simulations of the thermo-mechanical loads affecting the workpiece during the process are performed.

Abstract: This work analyses the production of Al based composites with particulate reinforcement, via mechanical alloying. Composites were produced by mixing Al and NbAl3 powders by high energy mechanical alloying, under liquid nitrogen atmosphere, followed by cold pressing and hot sintering; and by controlling NbAl3 phase precipitation in liquid Al (in situ formation of the reinforcement). Results on composite produced from powders showed better distribution and incorporation, besides finer dispersion of particles in the matrix when mechanical alloying is employed. In this case, high dispersion on particulate phase was found despite predominance of small particles; there are no evidence of interface formation. When composites are produced by in situ formation of NbAl3 intermetallics, results showed that the formation of the reinforcement directly from the liquid matrix and the peritectic reaction between NbAl3 and liquid Al, provide a perfect reinforcement/matrix interface. Products showed good mechanical properties, good wear behavior and reduced thermal expansion.