Cu-10 wt.% Al Alloys Produced by Spark Plasma Sintering of Powder Blends and a Mechanically Alloyed Mixture: A Comparative Investigation

Abstract

Cu–Al bronzes are interesting metallic materials, demonstrating higher hardness, higher wear resistance, higher corrosion resistance and a lower friction coefficient as compared with unalloyed copper. The powder metallurgy approach to the fabrication of these alloys presents opportunities to tailor their phase composition and grain size. In the present work, the structural characteristics, phase composition and properties of Cu-10 wt.% Al alloys obtained by spark plasma sintering (SPS) of powder blends and a powder obtained by mechanical alloying (based on Cu(Al) solid solution) are reported. Alloys with different interaction degrees between the metals were obtained by SPS. The blends demonstrated better sinterability than the mechanically alloyed powder: a nearly fully dense alloy was obtained by SPS of the blend at 480 °C, whereas a temperature of 800 °C was necessary to consolidate the mechanically alloyed powder. The hardness and electrical conductivity of the sintered alloys were comparatively analyzed. It was shown that the Cu-10 wt.% Al alloys obtained without the mechanical alloying stage possess hardness and electrical conductivity comparable to those of the alloys obtained from the mechanically milled powder.

Spark Plasma Sintering and Hot Pressing of Cu+Al Powder Mixtures and Pre-Deposited Cu/Al Layers

“…Materials formed via reactions between metals are interesting from the viewpoint of achieving new sets of mechanical and functional properties [1][2][3][4]. The binary Cu-Al system is the basis for the fabrication of Al-based alloys [5,6], aluminum bronzes [7][8][9][10][11] as well as composite structures and joints [12][13][14][15][16][17][18][19][20][21]. In bronzes, a higher mechanical strength and a better corrosion resistance than those of pure copper are sought.…”