Plain water jet cleaning of titanium alloy after abrasive water jet milling: Surface contamination and quality analysis in the context of maintenance

Abstract

Abrasive water jet (AWJ) milling process, though being an effective alternative to conventional machining for difficult-to-machine materials, induces abrasive embedment which is an issue for repair application by structural bonding. In this context, the effectiveness of cleaning Ti6Al4V specimens by Plain Water Jet (PWJ) post AWJ milling is studied. For this, Ti6Al4V specimens are milled by AWJ process with varying parameters to create several levels of surface quality and contamination. Different characterization techniques have been used to perform a multi-scale analysis of the machined surfaces and surface quality has been quantified by an innovative criterion called "crater volume" (Cv). Then the specimens are subjected to PWJ cleaning operation (using a single set of parameters chosen after preliminary study). Finally, surface texture analysis and contamination quantification is performed and compared with the AWJ milled surfaces. The results revealed that PWJ cleaning reduced the surface contamination by 65% without any significant change in Cv, surface texture and topology. However, it was found that it was impossible to dislodge deeply embedded particles. The comparison of pre and post-cleaning contamination levels also revealed that PWJ cleaning process efficiency depends on the AWJ milling parameters (mainly pressure).

Multi-scale analysis of the damage and contamination in abrasive water jet drilling of GLARE fibre metal laminates

“…8b). These craters might be the footprint of embedded particles which were removed by the jet during the cutting operation, as observed by Sourd et al [53] in the case of AWJ milling of titanium alloy Ti6Al4V. Two types of defects are also noticed in the GFRP plies: unevenly cut fibres (cf.…”

Effect of process parameters of Plain Water Jet on the cleaning quality, surface and material integrity of Inconel 718 milled by Abrasive Water Jet

“…The grit embedment ranges from 7 % to 14 % of the total surface area, depending on the AWJ process parameters. This is way lower than the grit embedment reported in [10] when milling Ti6Al4V by AWJ, which was around 40 % of the total surface area. This can be due to the machinability of the two materials.…”

“…However, the use of Plain Water Jet method for addressing the problem of grit embedment induced by AWJ milling is until today scarcely studied in the literature [3,10,15]. Moreover, there is a knowledge gap in the literature concerning surface integrity aspects after PWJ cleaning method (surface quality, material thickness removed, residual stresses, hardness, etc.).…”

“…These abrasive particles may be act as fatigue crack initiators [2,3,8], detrimental condition for a finished surface or for subsequent processes in repair application of damaged aircraft engine components where 3D additive manufacturing (AM) technology is deposited [9]. In metallic materials, it has been reported up to 40 % of the total area of a milled surface consisted of grit embedment, and in the best cases, 5 %, depending on machining conditions [3,[5][6][7]10].…”