| dc.description.abstract | Over the past decade, high-entropy alloys caught attention due to their unique alloy design and properties. Most of high-entropy alloys (HEAs) are composed of equal-ratio transition elements, and it led to high density (> 8 g/cm3). In this study, the effect of Al on the evolution of microstructure and mechanical properties of light-weight Ti60AlX(NbVCr) 40-x alloy in the as-cast condition and after heat treatment will be investigated. The resulting alloys are Ti60Al6(NbVCr)34, Ti60Al8(NbVCr)32, Ti60Al10(NbVCr)30, Ti60Al12(NbVCr)28, and Ti60Al18(NbVCr)22. These alloys are denoted as Al6, Al8, Al10, Al12, and Al18, respectively.
All samples were produced by vacuum arc melting (VAM) and drop casting. The XRD results reveal that the as-cast samples are BCC structured. The Hv hardness of the as-cast sample exhibited an increasing trend with increasing Al content, from 311 Hv of Al6 to 399 Hv of Al18. The compressive yield strength increased from 973 MPa of Al6 to 1269 MPa of Al18, and even, the tensile yield strength increase from 895 MPa of Al6 to 960 MPa of Al12. Unfortunately, the as-cast Al18 alloys did not present ductile property.
After heat treatment at 900ºC for 6, 12 and 24 h, all annealed samples exhibit slightly higher strength, but siginificantly decrease in ductility. At noted that all became more brittle at 900ºC for 24 h.
These light-weight Ti60AlX(NbVCr) 40-x alloys demonstrated excellent tensile ductility in the as-cast condition. With high specific strength and ductility, these alloys are promising in the application of energy and transportation industries. | en_US |