High cycle fatigue behavior of a nanostructured composite produced via extrusion of amorphous Al89Gd7Ni3Fe1 alloy powders

Effects of load ratio, R, and test temperature on high cycle fatigue behavior of nano-structured Al–4Y–4Ni–X alloy composites

“…The terms 'onset of nonlinearity' in the load displacement curve, and 'breaking strength based on elastic calculation' will be used instead of 'yield strength' and 'bend strength', respectively, to represent the results of the quasi-static 3 point bending tests in this work, to avoid any errors that may arise from the use of results obtained from bending tests instead of tension tests. In addition, the modulus of elasticity has been measured using acoustic techniques and is similar to that reported previously [24] for Al-Gd-Ni-Fe composite that exhibited Young's modulus of (86-89)GPa.…”

“…These nanostructured materials possess very high breaking strength compared to the strongest conventional precipitation hardened aluminum alloys that have a tensile strength of 500-650 MPa [29]. The present materials also exhibited higher strength in comparison to the Al-Gd-Ni-Fe nanostructured composites reported elsewhere, as well as similar beneficial effects of increasing the ER on subsequent properties [24]. Elastic constant measurements using acoustic techniques revealed Young's modulus (E) in the range of 86-89 GPa similar to that reported previously for Al-7Gd-3Ni-1Fe nanocomposites [24] in comparison with conventional high strength aluminum alloys that exhibit 70 GPa.…”

“…The processing details of the Al-4Y-4Ni-X nano-structured composite aluminum alloys created by extruding the atomized amorphous powders at different extrusion ratios are similar to that reported previously [24] and other ongoing work on these materials [9][10][11].…”

“…Although not investigated presently, previous TEM observations of extruded Al-Gd-Ni-Fe nanostructured alloy revealed that increasing the ER produced some coarsening of the nano-sized particles [24].…”

The effect of mixed mode I/II on the fracture toughness and fracture behavior of nano-structured metal matrix composites

“…Hot extrusion of the amorphous powders results in the formation of an ultra-fine structure consisting of 35 vol% of nano-structured intermetallic particles embedded in the nominally pure a-Al matrix surrounded by the monolithic aluminum tube. The microstructure, fracture toughness, fatigue crack growth and high cycle fatigue behavior of the nanostructured composite are summarized elsewhere [15][16][17].…”