Preparation of Al–La master alloy by ultrasonic method and modification on Al alloy

In this study, two kinds of Al–La master alloys were prepared by ultrasonic method and ordinary mixmelting method, and both of the alloys were added into the Al alloy.Then, the microstructure of Al–La master alloy and the modification effect on the Al alloy were investigated using optical microscope(OM), X-ray diffraction(XRD), scanning electron microscope(SEM), and energy disperse spectroscopy(EDS).The results show that because of ultrasonic cavitation and streaming, the grain size of Al–La master alloy prepared by the ultrasonic method is refined, which distributes evenly.And, there is no gas hole,inclusion, or segregation in the Al–La master alloy with aAl, La, and La3Al11.Furthermore, Al–La master alloys show a nice modification for Al alloy, which is much better than that prepared by ordinary mix-melting method.

Fluidity of ADC12+xLa aluminum alloys

The influence of rare earth lanthanum and pouring temperature on the fluidity of ADC 12 aluminum alloy was studied through spiral fluidity specimens by means of optical microscopy(OM) and differential thermal analyzer(DTA).The least squares regression method was used to give the best fitting between the function and the experimental data.The experimental results indicate that the rare earth lanthanum can significantly increase the fluidity of ADC 12 alloy.The fluidity increases with the addition of lanthanum.The DTA results indicate that with the addition of lanthanum,the range of crystallization temperature decreases,which increases the fluidity length.Especially,the range of crystallization temperature decreases by 32.66 % and the fluidity length is 1,321 mm(increased by 38.91%) when the addition of lanthanum is 0.6 wt%.Furthermore,with the increase of pouring temperatures,the fluidity length increases linearly between 670 and 760℃.