Investigation of Abrasive Aqua Jet Hole Making (AAJHM) parameters using desirability analysis on Inconel-625 space alloy

Inconel-625 is one of the high-strength space alloys with wide applications in aerospace industries and corrosion resistance environments. The applications of Inconel-625 material require blind holes with adequate quality characteristics. In the conventional method, the hole-making on Inconel-625 is difficult due to its mechanical behaviour. The abrasive aqua jet machining process can cut hard and brittle materials among various unconventional machining processes. This work proposes to determine the ideal values of process parameters to generate quality holes on Inconel-625 space alloy by optimizing the abrasive aqua jet hole-making process parameters using a desirability analysis. Abrasive jet pressure (AJP), gap distance (Gdi), traverse speed (Tspeed), and abrasive mixture (Abrmix) of garnet and silicon carbide were identified as potential process variables. The quality hole surface is discussed through surface roughness (SR), erosion rate (Er), circularity error (CI), and cylindricity error (CY). The experimental investigation discloses that SR, CI, and CY decreased by 27.35 %, 56.23 %, and 42.56 %, and Er increased by 32.83 % when the AJP reached its higher value of 300 MPa. According to desirability analysis, the optimal level of machining parameters for numerous solutions is AJP = 300 MPa, Gdi = 1 mm, Tspeed = 96 mm/min, and Abrmix = 100%SiC (AJP-2, Gdi-2, Tspeed-1, Abrmix-2). The ANOVA investigation revealed that AJP was the most contributed parameter, trailed by Abrmix as 100%SiC. SEM and 3D images were used to analyze the surface topography of the hole surface of Inconel-625.