Heat transfer during melt spinning of AL-7%Si alloy on a Cu-Be wheel

Transient heat transfer models of the single-wheel melt-spinning process are developed and applied to quantify the effect of process variables including interface depressions on solidification, temperature evolution, thickness variations, and surface depressions in the cast product. Firstly, a transient one-dimensional heat-transfer model of the melt-spinning process called STRIPlD was developed for Al -7% Si strips on a Cu-Be substrate and validated. Next, transient two- and three-dimensional heat-transfer solidification models of the process were developed and validated using the STRIP1D model. The models have then been used to understand the effect of process conditions including casting speed, puddle length (length of contact zone), gap height, superheat and interfacial depressions (gaps) on heat transfer in the strip, with the help of experimental measurements from a pilot caster in Cornell. The effects of interfacial boron nitride deposits and air gaps were quantified by measuring and modeling longitudinal and transverse surface depressions observed on the wheel-side surface of the strip. Interfacial depressions decrease heat conduction to the wheel and thereby cause surface depressions on the opposite side of the strip. The predicted depression shapes match well with experimental measurements. The control of surface depressions in the melt-spinning process could enable strip casting with imprinted textured surfaces.