Effect of the Preparation Methods of Me+Al Powder Blends on the Compaction Behavior, Structure, Phase Transformations, and Properties of the Compacted Aluminides of Transition Metals

Abstract:

The effect of the methods for preparing powder blend by conventional milling (Me+Al particles), attriting (Me/Al/ Me/Al composite particles), and plating of Me by Al (Me/Al composite particles) on the structure, internal stress level, and compactability of the powder blends as well as the structure and phase composition of the MeAl compacts was investigated. The Me+Al→MeAl exothermic reaction of these powders occurs at T≥650°C. The reaction sintering (RS) or hightemperature self-propagation synthesis (HTSPS) occurs through the formation of Al melt (liquidphase reaction) and lower-melting MeAl3, Me2Al3, Me3Al aluminides. An increase in the level of internal stresses (IS) upon attritting activates RS at lower temperatures and decreases the value of high-temperature exoeffect. This suppresses the HTSPS development. A large high-temperature exoeffect ensures the intensity and completeness of the reaction interaction, and the application of pressure upon RS or HTSPS provides a high, near-theoretical density of the compacted material.

• Periodical: Materials Science Forum (Volumes 534-536)
• Pages: 513-516
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.534-536.513
• Online since: January 2007
• Authors: K.B. Povarova, N.K. Kazanskaya, A.A. Drozdov, A.E. Morozov, A.G. Nikolaev
• Keywords: Aluminides, Attriting, Composite Particle, Density, Exothermic Reaction, Internal Stress, Phase Composition, Plating, Powder Blends, Reaction Sintering

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