Search

• Al-7075 was reinforced by different contents of Fe-based metallic glass particles. • The composites were prepared by spark plasma sintering and hot extrusion. • The composites possess higher mechanical properties than unreinforced Al-7075. • The composites are reinforced mainly by thermal mismatch and grain refinement. Metallic glass (MG) reinforced aluminum matrix composites (AMCs) have attracted the interest of many researchers in the past few years. In this study, Fe 50 Cr 25 Mo 9 B 13 C 3 metallic glass (FMG) particles reinforced 7075 aluminum matrix (Al-7075) composites were prepared by spark plasma sintering (SPS) technique. The microstructure of the composites showed good interface bonding between the FMG particles and the matrix. The micro-hardness of the composite with 30 vol% FMG particles reached 160.63 HV, which was increased by 30% compared with that of Al-7075 (119.3 HV). The ultimate compression strength (UCS) of the composite was also improved significantly from 596 MPa for Al-7075 matrix to 749 MPa for the composite reinforced with 30 vol% FMG particles, and the compression strain of the composite reached 22%. These results indicate that the mechanical properties of the composites can be enhanced by adding high volume fraction FMG particles. The enhancement of the strength is resulted from multiple strengthening mechanisms, and the main contributions come from the thermal mismatch and grain refinement. [ABSTRACT FROM AUTHOR]

Abstract Most bulk metallic glass systems with high glass-forming ability are doped with precious metal(s) or toxic element(s), like palladium and beryllium, leading to relatively high cost or low safety in use. In this work, the glass-forming ability, crystallization kinetics and mechanical properties of the Zr 55 Co 25 Al 20 and Zr 52 Co 25 Al 23 bulk metallic glasses prepared by water-cooled copper mold suction casting are investigated in detail. The results show that Zr 52 Co 25 Al 23 has a wider supercooled liquid region, a higher thermal stability and a higher glass-forming ability than the Zr 55 Co 25 Al 20 amorphous alloy. At the same time, Zr 52 Co 25 Al 23 has a higher activation energy of crystallization than Zr 55 Co 25 Al 20 amorphous alloy, indicating that Zr 52 Co 25 Al 23 has a higher resistance to crystallization than Zr 55 Co 25 Al 20. Investigation of the mechanical properties reveals that Zr 52 Co 25 Al 23 also has a higher fracture strength of up to 2308 MPa and a higher specific fracture strength of up to 3.78 × 105 N m kg−1 compared with 316L stainless steel, Ti-6Al-4V, as well as Mg-, Ti-, and other Zr-based BMGs. Graphical abstract Image 1 Highlights • Zr 52 Co 25 Al 23 (Zr52) and Zr 55 Co 25 Al 20 (Zr55) amorphous alloys were investigated. • Lower Zr/Al ratio leads to a wider SLR, higher thermal stability and higher GFA. • Zr52 has a higher resistance to crystallization than Zr55. • Zr52 has larger plasticity and higher specific strength than Zr55. [ABSTRACT FROM AUTHOR]