Effects of fundamental process factors on the properties of AZ31 magnesium alloy strip produced by the melt drag process

Abstract

The purpose of this study is to produce magnesium alloy strip of good quality at lower cost than the conventional rolled sheet. Melt drag process has many advantages such as the low production cost and the improved microstructure because the strip is made directly from molten metal by rapid cooling. In this study, we designed the experimental device for molten magnesium casting and researched the effects of the basic factors such as roll speed, pouring temperature and melt height on surface quality, strip thickness, Vickers hardness and microstructure. The AZ31 magnesium alloy strip was able to be produced at roll speed from 1 m/min to 90 m/min, and the thickness changed from 0.5 mm to 8.8 mm. The higher the pouring temperature, the thinner the strip thickness became. And the higher the melt height, the thicker the strip thickness became. The Vickers hardness is about 47HV. The microstructure of the produced strip was equiaxed and the distribution of crystal grain size was relatively uniform. The average crystal grain size was from 50 μm to 300 μm depending on the experimental conditions.