Low-cost beta titanium cast alloys with good tensile properties developed with addition of commercial material

The low-cost beta-titanium alloys, Ti-Cr-Al-Si, have been designed by the addition of a commercial Al-based die-cast alloy (ADC12, Al87.38Cu0.95Si10.65Mg0.27Zn0.30Fe0.32Mn0.11Cr0.02 in at.%) containing Si content. The microstructural investigation on Ti84-xCr16(ADC12)(x) (x = 6, 16 at.%) alloys exhibited that the addition of 6 at.%ADC12 completely dissolved in the beta-Ti phase, and exhibited reasonable yield strength by solid solution hardening of the beta-Ti phase with large plasticity. The addition of 16 at.%ADC12 effectively reduces the cost of the beta-titanium alloys and induces microstructural evolution with formation of Ti-silicide. The beta-Ti phase containing high content of solutes and the very fine Ti5Si3 phase that segregated in the interdendritic regions, due to Si solute partitioning during dendritic solidification, mediates outstanding tensile mechanical properties (1015 MPa in yield strength and 17.5% in elongation). These results reveal that the alloy designs using the commercial materials containing various solute elements can facilitate the development of the competitive low-cost beta-titanium alloys with excellent mechanical properties. (C) 2019 Elsevier B.V. All rights reserved.