The Investigation of Microstructure and Mechanical Property of Incorporation of Cerium Oxide to AA2219 Through Liquid Forging Technique

Abstract

In this study, an attempt is made to prepare aluminum metal matrix composites of AA2219 with varying reinforcement of weight percentages of cerium oxide (X = 0.5%, 1%, 1.5%, and 2%) by liquid metallurgy technique involving liquid forging operation. The incorporation of rare earth oxide to AA2219 through liquid forging technique offers excellent solubility of the solute atom along with near-net shape capability, higher materials property, and reduced porosity level when compared with conventional casting route. The reinforcement of cerium oxide improves mobility, casting microstructure, reduces shrinkage and hot tearing tendency of AA2219. The AA2219 composites sample were casted at the following process parameter such as the applied pressure load 350 MPa, the heating die temperature 200 °C, melt temperature 750 °C, and 60 s dwell time. The main objective was to determine the effect of CeO2 particles on the microstructure and mechanical properties of AA2219 composites through liquid forging technique. X-ray diffraction studies revealed the presence of intermetallic phase present in the composites and the presence of CeO2 confirmed by EDS analysis. Scanning electron microscopy images showed a homogeneous distribution of CeO2 particles within the matrix and the grain boundaries. The reinforcement of CeO2 increase hardness of the composites with a maximum hardness of 123 VHN observed for 2 wt% CeO2 with AA2219. The tensile test indicated the significant effect of the CeO2 particles with an ultimate tensile strength of 232 MPa and 87 MPa yield strength when compared to the unreinforced material was around 130 Mpa and 75 MPa, respectively. Fractography showed ductile fracture mode failure and the increase in CeO2 decrease the level of strain rate.