Synthesis, structural and high frequency dielectric properties of polypyrrole (PPy)/holmium ferrite composites

Mechanical and physical properties of aluminium-silicon (Al-Si) casting alloys reinforced by Zinc Oxide (ZnO)

“…In other words, the more the amount of zinc oxide, the higher the hardness value. 5% Zr 101 Table 2 shows that the specimens reinforced with 0.05%, 0.1%, and 0.2% zinc powder had greater hardness values than those in the research conducted by Qasim et al [2] and Iman S et al [7]. The addition of , Ti and Zr generated more hardness but the amount of it was 5-20 times more than zinc oxide.…”

“…The photomicrographs of specimens reinforced with varying amounts of zinc oxide are presented in Figure 3a The microstructure of specimen reinforced with 0.05%, 0.1%, and 0.2% zinc oxide is shown in Figure 3a, 3b, and 3c, respectively. Figure 3a shows a uniform grain size distribution with some dendrites [2], [7], [10]. Compared to Figure 3a, Figure 3b shows a smaller grain size but larger dendrite size; solidification occurred much faster in this specimen [2], [7], [10].…”

“…Figure 3a shows a uniform grain size distribution with some dendrites [2], [7], [10]. Compared to Figure 3a, Figure 3b shows a smaller grain size but larger dendrite size; solidification occurred much faster in this specimen [2], [7], [10]. Figure 3c shows that the grains become smaller and denser, grain boundaries are more clearly visible, and the dendrite structure is smaller, and grains are distributed more evenly than the other specimens [2], [7], [10]…”

“…The process of metal casting includes melting the metal, pouring it into a mould, and letting it cool and solidify [1]. Aluminium-silicon casting alloys are widely used in automotive and aircraft industries because of their excellent properties such as low density, high strength-to-weight ratio, high corrosion resistance, good impact resistance, good thermal conductivity, and high wear resistance [2]. The addition of certain elements, such as calcium, sodium, strontium, and antimony, to aluminium-silicon alloys gives a fine eutectic structure or finer fibrous form [3].…”

“…Shin et al [14] studied the refining effect of aluminium alloy (A356) microstructures by conducting an exothermic chemical reaction called aluminothermic reaction on aluminium alloy (A356) and zinc oxide nanoparticles (ZnO, ~20 nm in size) and the results showed an improvement in mechanical properties. Qasim et al [2] studied the effect of adding zinc oxide nanorods to aluminium casting and found that it improved the mechanical properties.…”