Elimination of edge cracks and centerline segregation of twin-roll cast aluminum strip by ultrasonic melt treatment

Abstract

Ultrasonic-assisted twin-roll casting (UA-TRC) process was developed for the production of high quality 1050 aluminum alloy strip with minimum casting defects. Results of industrial-scale trials show that the strips obtained by UA-TRC exhibited a homogenized matrix composed of fine equiaxed grains. Meanwhile, robust evidence substantiates the feasibility of eliminating edge cracks and centerline segregation of the strips via the ultrasonic melt treatment. Scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD) techniques were utilized to clarify the cause of edge cracks and centerline segregation, and furthermore, the regime of elimination of such defects via ultrasonic treatment in TRC processing. The results of present study reveal that by introduction of ultrasonic prior to rolling, homogeneity of solute elements and fluidity of the melt can be enhanced. As a result, the production of non-cracked strips with homogenized matrix is promised.

Keywords

• Edge cracks
• Centerline segregation
• Ultrasonic
• Twin-roll casting
• Iron intermetallic