Ultrahigh strength Al-based amorphous alloys containing Sc

Abstract

Amorphous metallic alloys possess high strength characteristics, which are superior to crystalline materials. Here we report an influence of Sc addition on glass-forming ability, glass-transition behavior, supercooled liquid region, and mechanical properties of an Al84Y9Ni5Co2 glassy alloy. This paper also aims to present a promising (Al0.84Y0.09Ni0.05Co0.02)95Sc5 amorphous alloy. This alloy has an ultrahigh tensile fracture strength exceeding 1500 MPa, which surpasses those for all the other Al-based fully crystalline and amorphous alloys reported to date, in addition to high Young’s modulus of 78 GPa. The fracture surface of this new alloy exhibited vein pattern typical for amorphous alloys with good ductility, and multiple shear bandswere observed on the lateral surface. The ultrahigh tensile strength of the (Al0.84Y0.09Ni0.05Co0.02)95Sc5 amorphous alloy results from an increase in the interatomic constraint force by the addition of Sc, an element having highly negative enthalpy of mixing with Al, Ni, and Co and the highest chemical affinity with Al among the alloying elements.

Progress in studying the fatigue behavior of Zr-based bulk-metallic glasses and their composites

“…Over the last two decades, many glass-forming alloy systems were discovered, which involved binary, ternary, and multicomponent alloy systems. These metallic-glass alloy systems included Zr- [9,10], Fe- [11,12], Pd- [13,14], Al- [15,16], Ni- [17,18], Cu- [19,20], Mg- [21,22], and Ti-based alloys [23,24].…”

Structure and transformation behaviour of a rapidly solidified Al–Y–Ni–Co–Pd alloy

“…This concept has been recently supported by the results on Sc addition to the Al-Y-Ni-Co alloys [53]. The addition of Sc increased T x .…”

Development and Applications of Highly Functional Al-based Materials by Use of Metastable Phases

“…Furthermore, a number of shear slip steps are observed in the region just near the fracture surface edge, indicating that the Al-Y-Ni-Co-Sc glassy alloy has a good ductile nature in spite of the high tensile strength exceeding 1500 MPa. It is also noticed that the specific tensile strength of σ f /ρ for the glassy alloy exceeds 4.4 × 10 5 Nm/kg [13] . In addition to amorphous alloys in a ribbon form, Al-based amorphous alloy wires with a circular cross section have also been produced in the diameter range up to 100 μm by the melt extraction method.…”