PSI - Issue 33

Elvira Wahyu Arum Fanani et al. / Procedia Structural Integrity 33 (2021) 3–10 Fanani et al / Structural Integrity Procedia 00 (2019) 000–000

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1. Introduction Metal matrix composites have become one of the most developed materials in recent years. MMC is widely used for automotive components, aircraft structures, and other industries (Shi et al., 2014). MMC provides better properties when compared to other materials (Özdemir et al., 2000). The method commonly used to produce MMC is stir casting (Kumar et al., 2011), powder metallurgy (Prasad et al., 1991), plasma spraying (Tiwari et al., 1991), and squeeze casting (Kim et al., 2003). One type of MMC is Aluminum Matrix Composites (AMCs). In the industrial world AMC is used in the manufacture of engine blocks, brake discs, and automobile drums (Veličković et al., 2016)(Akbar et al., 2020). Aluminum was used extensively based on its superior properties, including high strength, low density, good wear resistance, fatigue resistance, good thermal conductivity, resistance to corrosion, low production costs, light weight, and easy shape (Özdemir et al., 2000). However pure aluminum is not stiff and strong enough that aluminum is not commercially used in industrial application (Samal et al., 2020). The mechanical properties of aluminum can be improved by adding Cu, Mg, Mn, Zn, Ni, and others. Aluminum with the addition of these elements is called an aluminum alloy. The classification of aluminum alloys is shown in Table 1.

Table 1. Classification of cast aluminum alloys (Purohit et al., 2018). Alloy Designation

Details

1XXX 2XXX 3XXX 4XXX 5XXX 6XXX

99% pure aluminium Cu containing alloy Si, Cu/Mg containing alloy

Si containing alloy Mg containing alloy Zn containing alloy

The conventional method in AMC production will produce low ductility due to high brittle reinforcement and uneven microstructure (LLorca, 2002). Secondary treatment is necessary in order to improve the properties of the composite (Goyal and Marwaha, 2016). The secondary treatment that can be done at AMC is metal forming. Metal forming is the process of changing the shape of a metal or workpiece by applying an external force so that plastic deformation occurs. It should be noted that the sharp angle of the specimen becomes an obstacle in the deformation process (Almeida et al., 2020). The purpose of metal forming is to change the workpiece into the desired new shape and improve the mechanical properties of the metal (Nouri et al., 2020). Various metal forming operations like rolling, extrusion, forging, etc. (Chandrasekhar et al., 2018). Forging is one of the oldest known metalworking process (Ajeet et al., 2015). Forging is the process of forming metal using the compressive force of a hammer or die (Orhadahwe et al., 2020). The advantages of forging when compared to other forming processes are superior mechanical properties, no material wasted, close geometrical tolerances, and near net shape (Purohit et al., 2017; Khemraj et al., 2018). The microstructure of the forged composites leads to a uniform particle distribution and improved mechanical properties (Özdemir et al., 2000; Ceschini et al., 2007; Deng et al., 2010). Based on the explanation above, this review will focus on the forging of the aluminum matrix composite by their effect on the mechanical properties of the aluminum matrix composites. The review also discusses extensively on the microstructure of forging on the aluminum matrix composites with clarity on its grain refinement. The review paper will help the researcher to have information about the forging of aluminum matrix composites 2. Forging The forging process is one of the oldest types of metal forming and is one of the most important methods in the metal forming process. Forging is classified based on several things as discussed as follows. 2.1 Based on temperature Forging can be done in hot or cold conditions. By this, forging is classified on temperature as in cold forging, warm forging, and hot forging. Warm and hot forging require heat when compressive forces are applied (Keshavamurthy et al., 2016). Cold forging is carried out at room temperature (Chandrasekhar et al., 2018). The