## 2 Special Issue Findings
The authors ([PERSON]; [PERSON]; [PERSON]; and [PERSON], from the Technical University of Darmstadt, Germany, and the University of Technology, Iraq) aimed to specify the microstructure and investigate the mechanical properties of Al alloys, into which different amounts of Fe\({}_{2}\)O\({}_{3}\) (3, 6, 9, 12, and 15 wt.%) were introduced with a constant Ag content of 1 wt.% [19]. The Al/Fe\({}_{2}\)O\({}_{3}\) + Ag hybrid nanocomposite samples were synthesised via powder metallurgy, and the microstructure was visualised via field-emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD) investigations. Furthermore, mechanical experiments, such as microhardness tests, compression tests, and wear tests, were performed to estimate the mechanical properties of the hybrid nanocomposites. The FESEM and XRD results showed that the Fe\({}_{2}\)O\({}_{3}\) and Ag nanoparticles were uniformly distributed and dispersed in the Al matrix. Compared with pure Al, the mechanical test values increased with increasing weight percentages of the reinforcing nanoparticles up to 12 wt.% Fe\({}_{2}\)O\({}_{3}\). Here, the microhardness was 34.19 HV, the compressive strength was 89.9 MPa, and the wear rate was about 1.8 \(\times\) 10\({}^{-8}\) g/cm for Al + 12 wt.% Fe\({}_{2}\)O\({}_{3}\) + 1 wt.% Ag. The authors claimed that the results of this work demonstrated an improvement in the mechanical properties of aluminium alloys. * The last article of this Special Issue was published by [PERSON]; [PERSON]; [PERSON]; and [PERSON], from the Technical University of Darmstadt, Germany, and the University of Technology, Iraq [20]. Here, the authors synthesised a nickel-titanium--silver (Ni-Ti-Ag) shape memory alloy by casting to investigate its microstructure and mechanical properties. Ag (grain size 1 mm) was integrated into Ni-Ti alloys with different weight percentages (0, 1.5, 3, and 4.5 wt.% Ag) to prepare shape memory alloys using a vacuum arc remelting (VAR) furnace. The microstructural analysis was performed using field-emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD), whereas the transformation temperatures of the Ni-Ti-Ag shape memory alloy were obtained via a differential scanning calorimetry (DSC) investigation. The results showed that Ag was homogeneously distributed in the Ni-Ti alloy. In addition, two primary phases (martensite phase and austenite phase) were formed with few impurities. The XRD investigation indicated that the number of Ag peaks showed an increase with the enhancement in Ag weight fraction. The DSC investigation revealed that the austenite transformation temperature began at \(-\)1.6 \({}^{\circ}\)C, and the transformation temperatures increased with increasing Ag content to 19.7 \({}^{\circ}\)C, 12.7 \({}^{\circ}\)C, and 12.3 \({}^{\circ}\)C, respectively. Increasing Ag content significantly affected the mechanical properties of the Ni-Ti base alloy in terms of its compressive strength and microhardness. The highest value of compressive strength was reached for the alloy with 3 wt.% Ag, whereas the microhardness tests showed a minor decrease with the increase in Ag weight fraction.