Ultrasonic processing is known to be an efficient means of aluminium melt degassing and structure modification with additional benefits of being economical and environmentally friendly. This paper reports on the kinetics of ultrasonic degassing and regassing of foundry aluminium alloys and on pilot-scale degassing trials. Efficiency of ultrasonic degassing is compared with conventional Ar rotary degassing. Direct measurements of hydrogen concentration in the melt by Foseco Alspek-H probe are used along with reduced-pressure test. The effects of ultrasonic processing on porosity are studied using 3D X-ray tomography.

This paper presents a novel method for interactive exploration of industrial CT volumes such as cast metal parts, with the goal of interactively detecting, classifying, and quantifying features using a visualization-driven approach. The standard approach for defect detection builds on region growing, which requires manually tuning parameters such as target ranges for density and size, variance, as well as the specification of seed points. If the results are not satisfactory, region growing must be performed again with different parameters. In contrast, our method allows interactive exploration of the parameter space, completely separated from region growing in an unattended pre-processing stage. The pre-computed feature volume tracks a feature size curve for each voxel over time, which is identified with the main region growing parameter such as variance. A novel 3D transfer function domain over (density, feature size, time) allows for interactive exploration of feature classes. Features and feature size curves can also be explored individually, which helps with transfer function specification and allows coloring individual features and disabling features resulting from CT artifacts. Based on the classification obtained through exploration, the classified features can be quantified immediately.

Ultrasonic processing is known to be an efficient means of aluminium melt degassing with additional benefits of being economical and environment friendly. This paper describes the performance of ultrasonic degassing in preparing melt for low pressure die casting. Efficiency of ultrasonic degassing is compared with conventional Ar rotary degassing, by direct measurements of hydrogen concentration in the melt with a Foseco Alspek-H probe and by reduced-pressure test in different stages of the casting process. Significant reduction in dross formation along with the similar efficiency of hydrogen degassing was shown for ultrasonic degassing as compared with conventional Ar rotary degassing. The mechanical properties, microstructure and porosity level of components produced by low pressure die casting after both degassing techniques are determined. The results show that the components produced after ultrasonic degassing treatment have similar hardness, tensile properties, porosity level and microstructure as the components degassed with conventional Ar rotary degassing.

Ultrasonic processing is known to be an efficient means of aluminium melt degassing and structure modification with additional benefits of being economical and environment friendly. This paper reports on the kinetics of ultrasonic degassing effect of foundry alloys. Direct measurements of hydrogen concentration in the melt by Foseco Alspek-H probe are used along with the reduced-pressure test. The effects of ultrasonic processing on structure, i.e. grain size and porosity, are studied using metallography and 3D X-ray tomography. This work is performed within the Ultragassing project funded by the European Union’s 7th Framework Program.