Effect of Ni Addition on the Morphology and Microstructure of Both Conventional Cast and Melt-Spun of Al–Si–Fe–Nb (at wt%) Alloy

The Effects of Nb Addition on the Microstructure and Mechanical Properties of Melt Spun Al-7075 Alloy

“…Therefore, particle size strengthening caused by the addition of Nb, which brought about refining of coarse secondary phases (Figure 4), can be one possible reason for the increment in the microhardness values. Moreover, as stated above, we concluded that Nb can be dissolved in the rapidly solidified aluminum matrix by looking at the XRD analysis (Figure 2(d)), which is in accordance with the reference [19]. Hence, other possible cause for the increment in the microhardness values can be solid solution hardening.…”

“…Moreover, it has been stated that in Al alloys, an increased concentration of modifier agent in liquid phase lead to an increased constitutional undercooling [35]. On the other hand, in reference [19], it has been stated that Nb can form a solid solution in Al-Si-Fe-Nb alloy, as well as diffuse into secondary phases (intermetallics). Hence, in this study we conclude that some Nb atoms played a role as a modifier agent in the liquid Al matrix and led to an increment in the constitutional undercooling, which resulted in the formation of rounded / globular-like intermetallic phases.…”

“…In order to further improve the mechanical properties of aluminum alloys, researchers make microstructure modifications by means of various additive elements such as Co, Ni, V, Sc, Ti, B and / or use new generation production techniques [7][8][9]. Methods such as precipitation hardening [10][11][12], deformation hardening [13,14], semi-solid casting [15,16] and/or various rapid solidification [2,5,[17][18][19] are applied to aluminum alloys whose strength cannot be increased by quenching. Many alloying elements are added to the aluminum alloy to refine the grain size by operating the heterogeneous nucleation mechanism.…”

Effect of Cooling Rate on the Microstructure Evolution and Mechanical Properties of Iron-Rich Al–Si Alloy

“…Increasing the cooling rate is an effective way to change the morphology of an intermetallic. Melt spinning is a typical rapid solidification method which is used in the preparation of inoculants due to its chemical uniformity and large solid solubility [14][15][16]. Additionally, the microstructure evolution has been reported to be dependent on the cooling rate and Fe content in the Al-Si alloy [17,18].…”