Study on the progress of solidification, deformation and densification during semi-solid powder rolling
Semi-solid powder rolling (SSPR) is a novel strip manufacturing process, which combines the features of semi-solid rolling and powder rolling. High-performance metallic strips can be successfully prepared by semi-solid powder rolling. Based on its features, solidification, deformation and densification occur simultaneously and collaboratively during rolling. Progresses of them during semi-solid powder rolling were investigated via temperature, rolling force and density. By using numerical and experimental methods, the factor of progress remarkability (F) was proposed in a recent study by Luo et al. (2014) and calculated to discuss their progress remarkabilities during the whole procedure. A modified calculation methodology was adopted to calculate the rolling force and finite difference technique was used to calculate the temperature change. The calculated results agree well with the experimental data. The results show that an appropriate roller temperature gives a suitable cooling rate and it decreases as the time increases. According to the factor of progress remarkability (F), solidification occurs quickly and is significant in the material supplying region and drag-in region while densification and deformation are remarkable in the densification region resulting in a good strip with a high density.