Materials Today: Proceedings
Effect of different parameters on surface roughness and material removal rate in abrasive water jet cutting of Nimonic C263
Introduction
The machining of high strength alloys, all brittle and hard to cut material can be performed effectively by abrasive water jet machine. This cutting method is more efficient compare to other machining process as it has lots of advantages like no heat effected zone, good surface finish, high flexibility [1]. In this cutting process, elevated pressure water jet strike the material by giving the momentum to the abrasive particle at mixing chamber. The material removal mechanism by Abrasive water jet cutting (AWJC) depends on the type of work piece material [2]. In case of brittle material, material removed by micro-cracking and inter-granular fracture at low impact angle [3]. Zeng et al. [4] noticed that a wave of stress produced by impact of high pressure jet causes fracture. They also observed that erosion rate is extremely correlated with grain size and fracture strength of work material. The material removes in case of ductile material by abrasive wear and plastic deformation. The micro-cracking happens at the top kerf and plastic deformation occurs at the bottom of the kerf [5]. It is applicable to many field by using many operations like peening [6], turning [7], forming etc. Many researchers analysed different parameters to optimise better machining properties. Selvan et al. [8] investigated the impact of multiple process parameters on depth of cut and surface quality after cutting of Kevlar-phenolic composites. They concluded that elevated jet pressure and increasing mass flow rate is preferential as it raises depth of cut and reduces surface roughness. But high traverse speeds reduces depth of cut and also reduce surface quality. Hreha et al. [9] attempted to determine the cause of vibration and acoustic emission during cutting and the correlation of surface texture with these. The influence of nozzle diameter, standoff distance and cutting velocity on average kerf width and surface roughness was optimized through regression model during abrasive waterjet cutting of TRIP-steel sheet [10]. Aich et al. [11] optimised effect of different machining parameters on depth of cut during abrasive waterjet cutting of borosilicate glass. It has been reported that the diamond abrasive produce high extremely erosion rate and surface quality during cutting of polycrystalline diamond [12]. The type of abrasive is also responsible for cutting quality. The garnet produce higher taper of cut compare to silicon carbide and aluminium oxides. The width of cut increase in case of SiC as it possess high hardness [13].The cut surface was also analyzed to identify the striation formation and variation of surface texture from top to bottom of the thickness [14], [15]. Various studies has been performed to investigate the surface pattern, surface quality in different materials but it is first time with a super alloy. In this investigation, the impact of distinct parameters on surface roughness and MRR has been studied and different surface pattern throughout the thickness has been determined.
Section snippets
Experimental work
The experiment conducted by Abrasive waterjet machine of model OMAX 55100. The movement of X, Y and Z axis are 2540 mm and 1400 mm and 150 mm respectively. Maximum standoff distance was 200 mm and maximum pressure of 380 MPa. (55.11 KSI) Kerf width has measured by Flash-2000 (SVW2002559) made by OGP, USA. The surface roughness was measured by Surfcom-1900SD. The work material shown on Fig. 1. The plate of Nimonic C263 super alloy of size 200 mm × 200 mm × 8.2 mm been taken. The sample cut from
Variation of MRR with standoff distance at different pressure
The MRR measured during experiment, and plotted as shown in Fig. 3. It is evident from the graph that as the SOD increases MRR decreases however, with the increase in pressure the MRR increases. This effect is the result of the scattering and variation of the jet energy. At 30 KSI pressure MRR is between 6.5 and 7 mm3/s, and at 45 KSI pressure it was above 11 mm3/s.
Different surface texture and HAZ
The surface texture throughout the thickness has shown in Fig. 4. The high kinetic energy water jet when strike the material, as
Conclusions
It can be concluded from experimental result as follow:
- •
MRR increases with increase of pressure and shows various patterns with SOD. MRR initially increases and after certain SOD it decreases. The high SOD increases the jet focus point and the loss of energy occurs due to scattering of jet.
- •
The surface quality reduces after certain cutting speed. At an elevated cutting speed with the oscillation of the jet increases leading to increase surface roughness. So, the low cutting speed is good for
Acknowledgement
The authors acknowledge Directorate of Advanced Material and Processes, Materials development division, Defense Research and Development Laboratory, Hydrabad, India for allowing to conduct the experiment.
References (15)
Comparison metal water jet cutting with laser and plasma cutting
Procedia Eng.
(2014)- M. Asme, A modeling study of metal cutting with abrasiwe waterjets, 106,...
- S. Paul, A.M. Hoogstrate, C.A. Van Luttervelt, H.J.J. Kals, Analytical modelling of the total depth of cut in the...
- J. Zeng, T.J. Kim, An erosion model of polycrystalline ceramics in abrasive waterjet cutting, 193, 1996,...
- S. Paul, A.M. Hoogstrate, C.A. Van Luttervelt, H.J.J. Kals, Analytical and experimental modelling of the abrasive water...
- et al.
Residual stress and surface properties of stainless steel welded joints induced by ultrasonic pulsed water jet peening
Measurement.
(2018) - et al.
Hybrid aluminium matrix composite AWJ turning using olivine and Barton garnet
Int. J. Adv. Manuf. Technol.
(2017)