H. Abdizadeh processed composite using A356 aluminum alloy and ZrO₂ by stir casting method. The vol.% of reinforcement varies from 5 to 15 percent, and the temperatures were 750, 850, and 950 °C, respectively. It was reported that aluminum alloy reinforced with ZrO₂ particles enhanced UTS and hardness compared to A356 aluminum alloy, and its maximum values were 232 MPa and 70 BHN, respectively. For 15 vol.% of ZrO₂ composition, the highest UTS, and hardness values were obtained [19].

Baghchesara, M. A produced composite using A356 aluminum alloy and ZrO₂ by stir casting method. Various samples of 5, 10, and 15 volume percent of ZrO₂ in different casting temperatures of 750, 850, and 950 °C were prepared. The maximum tensile strength was recorded in the sample having 15 vol.% ZrO₂ prepared at 750 °C, which shows an enhancement of 60% compared to the aluminium-356 parent alloy. Additionally, it has been concluded that the composite fracture was severely brittle by increasing ZrO₂ particle quantity and casting temperature [20].

M. Hajizamani fabricated composite using A356 and ZrO₂ by stir casting method. In this work, nanoparticles of ZrO₂ and Al₂O₃ were constituted to produce composites with a composition of 0.5–2 wt.% of the reinforcement. This work records that by raising the reinforcement, density reduced while yield, ultimate tensile strength (UTS), and compressive strength improved. The ductility of the composite specimens was low due to high porosity and the formation of voids. Additionally, hardness improved at one weight percent of Al₂O₃ and 10 weight percent of ZrO₂. However, for the hardness of the specimen at 1.5–2 weight percent of Al₂O₃ and 10 weight percent ZrO₂ again the hardness value came down [21].

G.Karthikeyan selected aluminum LM25 as the parent material, reinforced with 0–15% of zirconium oxide prepared by stir casting route. Wear and tensile specimens were made per ASTM G99 and ASTM B-557-M-94 standard. A surface roughness test was done on wear specimens. The test shows that a rise in ZrO₂ particles percentage promotes surface roughness value [22].

Using the stir casting method, S. Prajval prepared a metal matrix composite by combining aluminum A356 and titanium dioxide (TiO2) with various mica percentages (1%, 2%, 3%, 4%, and 5%). It has been concluded that the UTS value is highly influenced by the percentage of mica and TiO₂ present in the composite. Additionally, the UTS value is noteworthily influenced by the process of heat treatment and aging method. The hardness of the specimens increases when the reinforcement in the composite specimen increases [23].

T. Rajmohan studied the property of hybrid A356 metal matrix composite reinforced with mica and SiC particles. Micrographs were investigated with the help of SEM. EDX was used to study the material composition. The results showed that better hardness was obtained for the composition of 10 wt.% of SiC and 3 wt.% of mica. The rise in weight percent of mica enhances the wear-resistant property of the composite [24].

R. Raj processed 6061Al-B₄C, the composite containing different wt.% of B₄C using advanced stir casting method with bottom pouring set-up. The dispersion of particles of B₄C in the aluminum matrix, interfacial characteristics, and microstructural features was qualitatively studied using an optical microscope and field emission scanning electron microscope (FESEM). Microstructural characterization revealed that the distribution of B₄C in the metal matrix phase was comparatively uniform, and at some locations, small-scale agglomeration and clustering of particles were observed. Particle size distribution has been studied for the quantitative description of agglomeration of B₄C particles, revealing small-scale agglomeration of particles. Homogeneity and randomness of B₄C particulates across the matrix phase have been calculated by the quadrant method. The results show a random spatial distribution of particles with small-scale clustering [25].

B. P Beyrami fabricated composite using A356 and ZrO₂ nanoparticles. Samples of composites were made at different percentages of ZrO₂ (1.5, 2.5, and 5 vol.%). The casting temperatures were selected as 800–950 °C. Micrographs of composite samples were studied using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Mechanical properties such as compressive yield strength, toughness, and hardness were calculated. The experimental results depict that mechanical properties like compressive yield strength and hardness are noticeably picked up by adding ZrO₂ particles. The highest values were for samples containing 2.5 vol.% of particles fabricated at 850 °C [26].

Two sets of cast composite specimens were prepared by stir casting fixing the 10% of fly ash and varying (5% and 10%) zirconia by weight fraction. S. Malhotra et al. reported that the optimum casting conditions of the composite fabrication were attained with 10 wt.% ZrO₂ and 10 wt.% fly ash. There is a considerable increase in tensile, elongation, and hardness value [27]. M. Ramachandra synthesized composite using Al 6061 and ZrO₂ to study corrosion behavior by the stir casting process. This work reports that the corrosion rate of the parent material is higher than the cast composite, and the best property is achieved in 7.5 wt.% ZrO₂ specimen [28].

D. M. Patoliya prepared composite using Al 6061 and ZrO₂ by the stir casting process. Four specimens were prepared to vary wt.% from 0 to 7.5, keeping all other parameters the same. It is also reported that tensile strength, hardness, and impact strength have been promoted parallel to the rise in weight fraction of zirconium oxide particles in the Al 6061 matrix, but elongation decreased with increase in wt percent of ZrO₂ in the Al 6061 matrix [29].

P. R Thyla fabricated composite using Al 6061, Gr, SiC, and ZrO₂ by the stir casting process. Five different samples were prepared to study the corrosion behavior. It has been reported that the corrosion rate decreased due to the presence of ceramic particles in the matrix material. Specifically, 9% wt percent sample records a very minimum corrosion rate [30].

The above works of various researchers show the development of composites using aluminum alloy and various reinforcements with different particle sizes and compositions. It proves the successful development of composite. One of the main objectives of composite is to achieve high strength. Table 1 gives a detailed report of the metal matrix, reinforcement, and the tensile strength achieved.

From Figure 1, the highest strength reported is by M. K Akbari et al. using metal matrix A356 reinforced with 3 vol.% TiB₂ that results in 308 MPa and K. Amouri using metal matrix A356 reinforced 0.5 wt.% Nano-SiC that results in 295 MPa. The lowest strength reported is by V. Singh using aluminum alloy reinforced with 5% (weight) SiCp that results in 52.8 MPa, and B.V Ramnath using aluminum alloy reinforced with Al₂O₃—3% B₄C—2% and achieved a tensile value of 54.6 MPa. The above experimental work listed in Table 1 shows a vast deviation in tensile strength. Various factors can cause variation in tensile strength. This work analyzes the most influential factors, i.e., wettability, uniform distribution, cluster formation, etc., in detail [31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66].