Structure and Properties of Ca and Zr Containing Heat Resistant Wire Aluminum Alloy Manufactured by Electromagnetic Casting

Abstract

Experimental aluminum alloy containing 0.8% Ca, 0.5% Zr, 0.5% Fe and 0.25% Si (wt.%), in the form of a long-length rod 12 mm in diameter was manufactured using an electromagnetic casting (EMC) technique. The extremely high cooling rate during alloy solidification (≈104 K/s) caused the formation of a favorable microstructure in the ingot characterized by a small size of the dendritic cells, fine eutectic particles of Ca-containing phases and full dissolution of Zr in Al the solid solution. Due to the microstructure obtained the ingots possess high manufacturability during cold forming (both drawing and rolling). Analysis of the electrical conductivity (EC) and microhardness of the cold rolled strip and cold drawn wire revealed that their temperature dependences are very close. The best combination of hardness and EC in the cold rolled strip was reached after annealing at 450 °C. TEM study of structure evolution revealed that the annealing mode used leads to the formation of L12 type Al3Zr phase precipitates with an average diameter of 10 nm and a high number density. Experimental wire alloy has the best combination of ultimate tensile strength (UTS), electrical conductivity (EC) (200 MPa and 54.8% IACS, respectively) and thermal stability (up to 450 °C) as compared with alloys based on the Al–Zr and Al– rare-earth metal (REM) systems. In addition, it is shown that the presence of calcium in the model alloy increases the electrical conductivity after cold forming operations (both drawing and rolling).

Recycling-Oriented Design of the Al-Zn-Mg-Ca Alloys

“…Calcium, abundant in the earth crust, also very versatile in aluminides formation, specifically Al10CaFe2 and Al2CaSi2, favouring flexibility in recycling-tolerant Al-Zn-Mg-Ca alloy design. Based on the available information [17][18][19][20], seven phases containing Ca, Fe and Si ((Al,Zn)4Ca, Al10CaFe2, Al2CaSi2, Al3Fe, Al8Fe2Si, Al5FeSi and Mg2Si) may be in equilibrium with (Al) in the alloys of the considered system. The most probable distribution of the elements among these phases is given in Table 2.…”

“…However, the Nickel is not allowed in recycling-oriented plants as it is a very expensive material. Calcium seems to be far more preferential since it is the third most abundant metal in the earth's crust Recently, several works on Al-Ca-Fe-Si alloys showed that calcium may bind the impurities into finely shaped ternary phases Al10CaFe2 and Al2CaSi2 [17,18]. In our recent research on Al-Zn-Mg-Ca-Fe [19] and Al-Zn-Mg-Ca-Si [20] alloys we showed that the foregoing phases may appear as a very fine constituent.…”

Investigation of the Intermetallic Compounds Fragmentation Impact on the Formation of Texture during the as Cast Structure Thermomechanical Treatment of Aluminum Alloys

“…Nowadays, aluminum and its alloys are among the most promising materials [1][2][3][4][5][6][7]. One of the most common problems in the production of aluminum sheets and strips is the texture that develops during thermomechanical processing, which leads to anisotropy of mechanical properties that, in turn, reduces the stability of cold forming operations.…”

Influence of Mg Content on Texture Development during Hot Plain-Strain Deformation of Aluminum Alloys

“…The improvement of casting and thermomechanical treatment practices is one of the most demanding aspect of modern material science [1][2][3][4][5][6]. Combination of high plasticity, fairly low density and reasonable strength makes aluminum alloys indispensable in multiple present-day industries [7][8][9][10].…”