Characterization of grain structure and crystallographic texture variation during the production of a Properzi semi-product

Abstract

The solidification on the casting wheel is the first step of the Properzi process which is followed by rolling in several steps, in this case 11 rolling steps. The uniqueness of the technology is that the rolling occurs from 3 directions. Therefore, a completely unique texture develops in the product compared to classic rolling. This aluminium semi-product is the base product for wire drawing. The characteristic of the strand greatly influences the success of the wire drawing therefore, knowing the crystallographic texture is demanded. In this paper, the grain structure and crystallographic texture variation during the full production technology of a Properzi semi-product is characterised. The examined strand includes all the technological steps of the process (casting and the 11 rolling steps). To perform such investigation, strand the complete production must be stopped for sampling because of the closed and semi-continuous type of the process, Therefore, the presented work is unique. To characterize the semi-product, cross-sectional and longitudinal-sectional samples were prepared. Grain structure and X-ray diffraction (XRD) texture examinations were carried out on the two sample series. Based on the results it can be stated, that despite of the grain refinement, initially a columnar structure formed and a strong <100> texture developed. During rolling, the <111> fibre texture developed. After the last step, the initial <100> texture is still present besides the <111> fibre texture. Consequently, the initial conditions of the crystallization highly determine the developed texture of the semi-product.