Influence of overheating and cooling rate on the structure and physicochemical properties of Al-Cu alloys

The effect of overheating of the melt and cooling rate of alloys of the Al-Cu system with a copper content of 25.0 – 36.0% (mass.), the rest of the aluminum is investigated. It is shown that an overheating of the liquid at 50 – 100 K above the liquid-liquid line leads to the formation of a fine-dispersed eutectic structure and the inhibition of the formation of primary aluminum crystals in the pre-evacuation of alloys and the Al2Cu phase in hypereuvtectic alloys, in accordance. An increase in the melt overheating temperature by 150 K above the liquid-liquid line and the subsequent cooling at 103 – 104 K/s leads to the complete inhibition of the formation of primary crystals. An overheating of the melt on 100 – 150 K alloys above the liquid line and subsequent cooling with a velocity of 103 – 104 K/s reduces the rate of corrosion by 30 – 45% and increases the numerical value in 1.3 – 1.45 times the relative wear resistance, and the brittleness of alloys decreases in 1.2 – 1.35 times in comparison with the samples after casting. © 2019 Trans Tech Publications Ltd, Switzerland.