## 1 Introduction
Therefore, the most recent research is based on the use of nonconventional machining technologies where the mechanical and thermal properties of these materials do not adversely affect the forming process. This is the case in laser cutting. There have been several investigations concerning the use of this technology with MMCs. However, the thermal properties of MMCs influence the process negatively. Thus, [PERSON] and [PERSON] [9] determined that in an Al-SiC MMC, in spite of being viable and obtaining a roughness (Ra) of around 1.3 \(\upmu\)m with reduced shape defects, behavior appeared during the fusion of the material which could generate defects and even cause microfractures. Likewise, there have been studies on the use of the electro-erosion process, which is presented as a viable alternative for the forming of these materials [10]. However, as this process is generally slow, and its main attraction is to obtain good qualities, it should be combined with another process to improve performance, such as abrasive water jet machining (AWJM) [10; 11]. This unconventional process meets the necessary conditions for cutting in terms of time ratios, wear reduction, and absence of thermal defects. Thus, although waterjet cutting is an increasingly widely used technology, there are no optimal machining parameters for MMCs that reduce the occurrence of defects and improve the dimensional and geometric quality of the machined component [12]. Defects in AWJM are mainly due to distortions in taper and surface quality and are directly related to parameters such as Transverse Feed Rate (TFR), Stand-Off Distance (SOD), Water Pressure (WP), and Abrasive Mass Flow Rate (AMFR), as well as material conditions and material thickness. These defects produce a negative impact on the surface integrity of the parts obtained due to the progressive growth of roughness as the material thickness increases and the appearance of striation marks due to jet delay when it lacks kinetic energy [13]. As a result, up to three possible cutting regions can be obtained [12; 14], as shown in Figure 1:  
* Initial Damage Region (IDR). The impact of the jet deforms the surface of the material by the successive impact of particles. * Smooth Cutting Region (SCR). The jet still has sufficient kinetic energy and the roughness obtained is reduced. * Rough Cutting Region (RCR). Characterized by the detection of marks caused by jet delay at the output of the material. This is the area where the worst roughness results are obtained. In this article, the main objective is to minimize the formation of defects in MMC cutting through AWJM by controlling TFR, WP, and AMFR. To this end, up to 27 straight cuts were made while varying levels of parameters in order to identify their influence on the formation of the taper angle and the different cutting regions (IDR, SCR, and RCR). Macrographs were taken using stereoscopic optical microscopy (SOM) to measure the taper angle. Additionally, roughness measurements were carried out in different areas to analyze surface quality (Zone 1, Zone 2, and Zone 3). Finally, the results were analyzed through ANOVA and SEM in order to evaluate the influence of each test.