Effects of Specific Pressure and the Dual Refiner on Microstructure of the Squeeze-Cast 2024 Aluminum Alloy Drive Hollow Shaft

Abstract

Effects of specific pressure and the dual refiner of Al-5Ti-1B and Al-10RE on microstructure of the hollow 2024 aluminum alloy drive shaft prepared by squeeze casting in express locomotive were investigated in this paper. With the increasing specific pressure, the ɑ-A1 primary grains became rounder and smaller. With the specific pressure up to 120 MPa, the average grain size of the ɑ-A1 primary grains and the average equivalent roundness were 38 μm and 0.75 respectively. When the dual refiner was adopted, the average grain size of the alloy decreased obviously with a lower mass fraction of A1-5Ti-1B and a higher mass fraction of Al-10RE. However, no obvious change was detected in the average equivalent roundness. The roundness value ranged from 0.62 to 0.72. With the dual refiner of 1wt% Al-5Ti-1B and 3wt% Al-10RE, the average grain size of the alloy and the average equivalent roundness were 26 μm and 0.71 respectively.