Effect of Ultrasonic Treatment on Ti/Al Composite using Squeeze Casting: Microstructural Analysis and Mechanical Properties

Abstract

To segregate the Titanium (Ti) from the reinforcements of the molten scrap of Titanium/Aluminum (Ti/Al) composite, application of ultrasonic vibration is known to be one of the sound techniques. Various studies have been looked at the effect of ultrasonic vibration on the melting process, however not much have been investigated with respect to the solidification process. To fabricate Ti/Al composites in situ, ultrasonic vibration can be effectively used to compress the solidifying melt during the casting process. In this line, the present study focused to investigate the influence of ultrasonic vibration and squeeze pressure on solidification behavior of the α-Al matrix, characteristics of the matrix-reinforcements interface, and distribution of reinforcements. The experimental data indicated that when the amplitude was 60 μm, the Vickers hardness, yield strength, and tensile strength of composites increased by 8.6, 3.9, and 3.1 %, respectively, due to gravity casting. While the squeeze pressure was increased from 50 to 100 MPa, the mean grain size decreased from 90 to 60 μm during the ultrasonic aided squeeze casting (SC) process. However, as the squeeze pressure was raised, the microstructures became coarser and the mechanical characteristics weakened. Yield strength, and tensile strength were increased by 18.7% and 3.2%, respectively, when the squeeze pressure was 100 MPa.