Research on pressure loss and filling ability of semi-solid rheological behavior in squeeze casting

Abstract

The filling ability of alloy fluid under pressure is of great significance to improve the dimensional integrity and mechanical properties of thin-walled and slender rods formed by squeeze casting. Insight into the rheological behavior of squeeze casting is beneficial to improve the formability of complex structural parts by optimizing the squeeze casting process. In this work, the Archimedes spiral sample prepared by indirect squeeze casting was applied to investigate the variation of filling length with squeeze pressure and filling speed during the rheological process in squeeze casting. According to the temperature distribution characteristic during the alloy melt filling process, the alloy fluid state was discussed and the spiral filling was confirmed as a semi-solid rheological behavior. The calculation models of pressure loss and filling length were established respectively based on steady-state rheological behavior. Pressure loss is mainly affected by the melt viscosity which is determined by temperature distribution and filling speed of alloy melt in the channel. According to the agreement between the theoretical calculations and the experimental results, the pressure loss and filling length models have been confirmed to be used to quantitatively characterize the filling ability of the aluminum alloy melt in the squeeze casting process.