**1. Introduction**

Aluminum Metal Matrix Composites are favored over other conventional materials in aerospace, automotive, and marine applications because of improved properties such as high strength-to-weight ratio, good wear resistance, and so on. Graphene's mechanical, physical, optical, and thermal properties make it an outstanding metal composite reinforcement material. Pure aluminum graphene nanoplatelets (GNPs) were reinforced in a base matrix (pure Al) with different weight percentages to form aluminum metal matrix composites using stir casting [1, 2] powder metallurgy [3] and other techniques. The uniform distribution of graphene nanoplatelets [4, 5] in the aluminum matrix improves mechanical properties significantly. Stephen et al. [6] discovered that graphene-aluminum

nanocomposites had lower strength and stiffness than pure aluminum reinforced with multi-walled carbon nanotube composites due to the production of enhanced aluminum carbide with the graphene filler. Venkata Subbaiah et al. [7] investigated the microstructural and mechanical properties of AA7075-GNPs. In an aluminum 7075 base matrix, ultrasonic-assisted stir casting was used to produce graphene nanoplatelets varying from 0.5 to 2.0 wt%. The composite with 0.5% GNPs had the highest tensile strength and microhardness due to the less porosity and uniform distribution of GNPs in the AA7075 matrix. According to Bhanu Prakash et al. [8], the microstructure and mechanical properties of aluminum 7075 graphene nanoplatelets ranged from 0.50 to 2 wt% in base matrix fabricated using the stir casting technique. In comparison with other weight percentages, AA 7075–1.5% GNPs provided the composite with better mechanical properties. Due to the graphene's uniform distribution with the base metal, Muhammed Emre Turan et al. [9] discovered that adding graphene to pure magnesium in different weight proportions improved hardness values. Xin Gao et al. [10] stress the contents of graphene reinforced with base minerals. The effect of graphene on the tensile strength of the prepared composites increases by 0.3 wt% as the graphene content increases. As the proportion of graphene in the composite increases, the tensile strength and percentage of elongation to fracturing decrease. A systematic approach to GNP composites'selection is necessary to choose the best material for a given application. The correct material selection technique entails precisely describing the application requirement in terms of mechanical properties, primarily for the utility class defined in the proposed application. Various researchers have used MADM methods such as VIKOR, EDAS, WSM PROMETHE, and TOPSIS to select the best material for specific applications in a range of fields such as automotive [11–16], marine [17, 18], medical [19], and agriculture [20–22]. The VIKOR method outperformed the other 10 most common methods for selecting suitable materials for a sailing boat mast, a flywheel, and a cryogenic storage tank, according to the author [23]. The optimal material, according to the researcher [24], is solely determined by the criterion's maximum priority value. The most conclusive of the three MCDM methods is VIKOR (TOPSIS, VIKOR, and PROMETHEE). Caliskan et al. [25] rated the materials using the PROMETHEE II, TOPSIS, and VIKOR methods and compared the results obtained by each process. Tungsten carbide-cobalt and Fe-5Cr-Mo-V aircraft steel were found to be the best materials for tool holder production. A new version of the VIKOR method, based on criteria for selecting the best material, particularly in the biomedical field, was proposed by Jahan et al. [26]

## **2. Problem description and experimental details**

In this research, the best material for aircraft application was chosen from five options of aluminum graphene nanoplatelet composites. **Figure 1** depicts the beneficial and non-beneficial criteria. MADM's EDAS and VIKOR methods are used to choose the right option. Procedural steps for criterion methods are represented in **Figure 2**.

### **2.1 Composite fabrication**

Stir casting has been used for the manufacturing of pure aluminum GNPs composites because it has a lower initial cost than other fabrication techniques. The author detailed the manufacturing of Al-GNPs composites in his prior work [1]. Mechanical stirring was used to distribute the reinforcing phases in the molten matrix metal during the fabrication process. **Table 1** displays the matrix and reinforcing materials used in the composite fabrication process.

*Selection of Optimal Material from Stir Cast Aluminum Graphene Nano Platelets… DOI: http://dx.doi.org/10.5772/intechopen.100478*

**Figure 1.**

*Beneficial and non-beneficial criterion.*

#### **Figure 2.**

*Applied steps for EDAS and VIKOR.*


**Table 1.**

*Material and reinforcement for composite fabrication.*
