Evaluation of the effect of ultrasonic degassing on components produced by low pressure die casting

Abstract

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 (LPDC). 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 similar efficiency of hydrogen degassing was shown for ultrasonic degassing as compared with conventional Ar rotary degassing. Mechanical properties, microstructure and porosity level of the components produced by LPDC after both degassing techniques are determined. 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.