Surface properties and fatigue failure analysis of alloy 718 surfaces milled by abrasive and plain waterjet

Abstract

This work analyzes the surfaces obtained in Alloy 718 when they are milled by Abrasive Waterjet (AWJ) at different conditions, and the effect of main process parameters on the characteristics of these surfaces. This analysis revealed that all surfaces have a homogeneous roughness in the transversal and the longitudinal directions, present embedded abrasive particles and have hardened about 50% with respect to the untreated bulk Alloy 718. On the other hand, Plain Waterjet (PWJ) technology was used for removing the abrasive particles embedded in surfaces of Alloy 718 milled previously by AWJ technology. The effect of this process on the surface characteristics is also analyzed. For all tested conditions, this technology removed all the particles embedded in the surface. In addition, the PWJ technology process in general smoothened the surfaces produced by AWJ milling and it also released nearsurface stress. Finally, fatigue tests revealed lower performance of the treated specimens in comparison to untreated specimens, due to crack-like surface irregularities introduced by the treatments.

Surface Quality and Free Energy Evaluation of s275 Steel by Shot Blasting, Abrasive Water Jet Texturing and Laser Surface Texturing

“…Abrasive water jet texturing can produce surfaces with a high roughness finish. But, due to the nature of the process and the high kinetic energy given to the abrasive particles, they can remain adhered to the surface as indicated in the results obtained by Rivero et al [36] and Suarez et al [41]. This is corroborated in Figure 3, where by means of EDS analysis and knowing the chemical composition of the abrasive particles used, the remains adhered to the surface after texturing can be observed.…”

“…Abrasive water jet texturing can produce surfaces with a high roughness finish. But, due to the nature of the process and the high kinetic energy given to the abrasive particles, they can remain adhered to the surface as indicated in the results obtained by Rivero et al [36] and Suarez et al [41]. levels.…”

“…However, there are no studies that relate the influence of surface quality and input parameters to the free surface energy generated. In addition, there is little information on the final state of the surface generated during this process and the possible inclusion or adhesion of abrasive particles on the surface [36].…”

Multi-scale characterization of material and surface integrity of Inconel 718 when milling by Abrasive Water Jet process: Context of repair application

“…Ay et al [22] investigated the effect of traverse speed on kerf shape in jet singles passes and concluded that lower traverse speed generates deeper depth of cut and wider kerf as a result of the exposure time leading to more overlapping area. Rivero et al [23] analyzed milled surfaces with different setting process parameters and reported that abrasive flow rate, pressure and stand-off distance have a significant influence on surface roughness. It was noticed an increase in roughness with an increase in pressure; whilst surface roughness decreases with increasing abrasive flow rate.…”

Experimental investigations on abrasive water jet machining of nickel-based superalloy

“…Rivero et al examined the surfaces achieved during abrasive water jet milling of alloy 718 at various machine settings and analysed the effect of control factors on the SR. They reported that clogging of abrasive particles and machined surfaces witnessed homogeneous surface finish in the longitudinal & transversal path and there was a 50% increase in the hardness of the machined alloy when compared with the untreated bulk alloy 718 [18]. Mieszala et al made an attempt to find the influence of microstructure and mechanical properties on the erosion mechanisms during ABWJ using controlled depth milling and single particle impact experiments performed on nano-crystalline, microcrystalline and single crystal nickel samples and concluded that the erosion rate of the target metal is found to correlate positively with grain size and negatively with hardness but this correlation is nonlinear [19].…”