## 1 Introduction
In UNS A92024-T3 aluminum alloys, studies have been carried out on the effect of compressive residual stress (CRS) generated by turning, concluding that the greater the residual compressive force generated, the greater the improvement in ultimate tensile strength (UTS) [45]. In addition, the use of cutting fluids reduces the friction between the tool and the chip, lubricates the tool-piece interface, dissipates the heat, and helps to remove the chip adhered to the tool surface [18; 29]. However, it causes environmental and health damage from the chemical additives it contains. To avoid this, there is a tendency towards almost dry cutting formulas such as minimum quantity lubrication (MQL) [33; 46] and dry machining [18; 19; 20; 40; 45], or new technologies such as cryogenic cooling [47]. These options provide new solutions for alloys such as titanium in which tool wear occurs due to its low thermal conductivity and high chemical affinity. However, working with extremely low temperatures produces a workpiece hardening and an increase in the cutting forces. Therefore, several studies have been recently published seeking solutions to this problem. In one of the studies, an internal cryogenic cooling for the tool that maintains the standard working temperature on the workpiece is used, reducing the cutting force by 54% and the tool wear by 90% compared to traditional cooling [48]. Other studies propose the use of an internal cryogenic cooling for the tool. In this direction, [PERSON] et al. [49] study the use of a cryogenic cooling with MQL lubrication that employs CO\({}_{2}\) as internal coolant, and [PERSON] et al. propose a hybrid system of cryogenic and MQL which clearly improves cutting forces, surface quality, and tool life [50]. A requirement commonly used by manufacturers in the automotive and aerospace sectors as well as in numerous studies on light alloy machining is the Arithmetical Mean Roughness, _Ra_ (\(\upmu\)m) [18; 19; 20; 40; 51; 52]. Therefore, _Ra_ (\(\upmu\)m) is the response variable chosen in this study to determine the optimum thickness of Mg-Al-Mg hybrid component plates for drilled parts in the aeronautical industry. Besides, it is used to compare the results with those obtained, in previous works, for other combinations of materials, Mg-Ti-Mg, of identical geometry. Furthermore, the research method that modifies a factor in each test is very time-consuming and does not provide knowledge of the interactions between parameters. The design of experiments (DoE) is an experiment-based modeling method that uses statistical techniques, such as analysis of variance (ANOVA) to process the data and find out about the factors of influence, the interaction between them, and their level of influence on the process [18; 19; 20; 51; 53; 54; 55; 56]. This study is part of a larger research project that includes several structural lightweight materials, machining processes, and lubrication/cooling systems. Two experimental tests were carried out in 2017, the first allowed to determine the factors with the greatest influence on the turning process in Al-Mg multimaterial specimens [19], the second studied the influence of the tool on the magnesium drilling process under different machining conditions on specimens [20]. In 2018, this knowledge was applied for the selection of the drilling tool for Mg-Ti-Mg multimaterial components in the search for the best dry machining parameters [18]. In 2019, a review of recent literature on hybrid composites was carried out which concluded that there is a clear scientific and automotive and aeronautical industry interest in the use of aluminum alloys being the single most commonly used material to form multimaterial combinations [21]. Consequently, two experimental tests were carried out on Mg-Al-Mg multimaterial specimens to find the most significant factors in the process and the best machining conditions by applying sustainable cooling/lubrication techniques such as dry machining and cold compressed air.