AN INVESTIGATION INTO THE EFFECTS OF RAPID QUENCHING ON THE SOLIDIFICATION OF AL-CU AND AL-MG ALLOYS

Rapidly solidified ribbons and air-cooled casting ingots of Al-Cu and Al-Mg liquids alloys were investigated using the X-ray diffraction met hod and optical microscopy. The effects of quenching rates on the amor phization have been established by a broad shoulder on the left side i n the X-ray diffractograms obtained from powders of the ribbon Al-Mg s ample. When comparing the diffractograms obtained from the ingots and the ribbons of both alloys the same crystals structures were encounter ed. From the shift of the positions of the peaks, it was found that so me residual stresses had arisen in the rapidly solidified ribbon sampl es. The difference between the peak heights of the ribbon and the ingo t of Al-Cu alloy shows that the beta-Cu phase in the ribbon is more st able than in the ingot.