Study of the microstructures and mechanical properties of aluminium hybrid composites with SiC and Al2O3

Abstract

Aluminium metal-matrix composites are widely produced with different ceramic compounds as reinforcements to enhance their properties and to suit various structural applications. The present work involves the fabrication of Al7075 composites with silicon carbide (SiC) and aluminum oxide (Al2O3) as reinforcements through stir casting. Four specimens were produced with different compositions comprising SiC (3, 5, 7 and 9 w/%) and Al2O3 2 w/% in all the combinations. Mechanical properties like ultimate tensile strength (UTS), yield strength (YS), percentage of elongation (% of elongation) and hardness (VHN) were examined, along with fractography studies. The microstructural characterization of the composites was also studied through micrographs obtained from the scanning electron microscope (SEM). The test results revealed that the increase in the w/% fractions of the reinforcement materials caused an increase in the tensile strength, yield strength and hardness of the aluminium composite, except for the % of elongation, which is reduced with the addition of ceramic particles.Kompoziti s kovinsko osnovo iz aluminija se pogosto izdelujejo z razli~nimi kerami~nimi spojinami kot oja~itveno fazo, in s tem postanejo uporabni za izdelavo razli~nih strukturnih aplikacij. V pri~ujo~i raziskavi so avtorji izdelali kompozite na osnovi Al zlitine 7075 z dodatkom delcev silicijevega karbida (SiC) in aluminijevega oksida (Al2O3) kot oja~itveno fazo med preme{avanjem taline. Izdelali so {tiri vzorce z razli~no vsebnostjo SiC (3, 5, 7 in 9 w/%) in v vseh primerih {e z dodatkom 2 w/% Al2O3. Dolo~ili so mehanske lastnosti izdelanih kompozitov -natezno trdnost pri pretrgu (UTS), mejo plasti~nosti (YS), raztezek (%) in trdoto (VHN). Nato so izvedli {e analize prelomov (fraktografijo) nateznih preizku{ancev s pomo~jo vrsti~nega elektronskega mikroskopa (SEM). Rezultati preiskav so pokazali, da pove~anje dodatka oja~itvene faze v obliki kerami~nih delcev povzro~i zvi{anje natezne trdnosti, meje plasti~nosti in trdote, zmanj{a pa se raztezek. Klju~ne besede: metoda litja s preme{avanjem, hibridni kompoziti, mehanske lastnosti in mikrostruktura

A review on primary synthesis and secondary treatment of aluminium matrix composites

“…The addition of reinforcement materials improves the mechanical integrity of aluminium. Figure 4 was adapted from the study of Pugalenthi et al (2019). It was observed that there was an increase ultimate strength (UTS) from 248 MPa in sample 1 to 325 MPa in Sample 4.…”

“…Mechanical properties of Al7075/SiC/Al 2 O 3 composite (a) yield and ultimate strengths (b) %elongation (c) hardness;1-Al7075 þ 3%SiC þ 2% Al 2 O 3 , 2 -Al7075 þ 5%SiC þ 2%Al 2 O 3 , 3-Al7075 þ 7%SiC þ 2%Al 2 O 3 , 4-Al7075 þ 9%SiC þ 2%Al 2 O 3(Pugalenthi et al, 2019).…”

Synergistic effect of graphene nanoplatelets and titanium dioxide nanopowder-reinforced aluminium nanohybrid composites on mechanical properties

“…Debonding leading to ductile fracture seems to be more dominant in samples 2, 3, and 4, which have comparatively low fractions of reinforcements and the presence of aluminium 7075 alloy in the majority. Transgranular fracture was demonstrated in the failure of aluminium 7075 composites, and it is evident that this fracture happens at grain boundaries and becomes disconnected at the moment of failure [51]. In figure 8(c) intergranular fracture can also be seen along with transgranular fracture that occurs along the grain boundaries of the metal.…”

Comparison between the Effect of Adding MSGNP and B4C-WC Nanoparticles on the Metallurgical and Mechanical Characterization of Al-7075 Composites Produced by Stir Casting

“…Additionally, it was noticed that silicon carbide (SiC) is a good strengthener in the alloy of Al [11]. Furthermore, the other employed additives in the previous studies are titanium carbide (TiC) [12], tungsten carbide WC [13], alumina (Al2O3) [14], Si3N4 [15], and AlN [16], as well as the results revealed that the addition of these reinforcements enhanced the performance of aluminum and its alloys. Moreover, the waste utilization in reinforcing the alloys of Al has been verified positive [17].…”