A Multi-Principal Element Alloy Combining High Specific Strength and Good Ductility

Al8Nb27Ti29V28Zr8 multi-principal element alloy (MPEA) was prepared via arc melting. In the homogenized + heat treated condition the alloy is composed essentially of a matrix possessing A2 disordered BCC structure and nanometer-sized particles of Al3Zr5 and Laves AlZrV phases. The alloy demonstrated high yield strength (1250 MPa) and good compressive ductility (38 % until fracture) at room temperature, and maintained a high yield strength at 700 ? (720 MPa). The density was measured as 6.34 g.cm- 3, resulting in a specific strength at 700 C of 113.6 kPa.m3/kg, near twice that of Ti6Al4V (67.7 kPa.m3/kg) and Inconel 625 (46.2 kPa.m3/kg) alloys, and more than three times higher than that of Ti-beta 21S (35.4 kPa.m3/kg). However, the tests performed and results obtained were not sufficient to explain the simultaneous high yield stress and ductility at room temperature.