Proceedings of SerbiaTrib '13

[11]. Figure 5 shows s the influence of traverse speedandabrasive mass flow on the waviness.10Abrasive mass flow rate [g/min]40220110440Figure 3. Appearance of the surface machined withabrasive water jetWaviness of the machined surface is alsoo animportant phenomenonn in the machining withabrasive water jet, Figure 4. It was found that thereis a primaryand secondary waviness on the surfacemachined with abrasive water jet [6]. Primarywaviness isa waviness with higher step values,while the secondary waviness has less step value.For all cutting parameters,iff the primarywavelength of the profile at the rough cutting zoneis smaller, the surface is smoother. . Guo [7] foundthat there isa dependence of the waviness step andfocusing tube diameter,while Kovacevic [8] founda correlationbetween waviness stepand a diameterof abrasive particles and the focusing tubediameter.Amplitude [mm]WavinessRoughnessWavelenghtFigure 4. Waviness and surface roughnessThe quality of the surface machined withabrasive water jet isinfluencedwith systemoperational process parameters such as traversespeed, waterjet pressure, abrasive flow rate,standoff distance, depthof cut and angle of cutting[9].Level of influence of certainparameterss isdifferent. The largest number of authors agrees thatthe most influential are traverse speed, s operatingpressure andthe abrasive flow rate. Traverse speedof the jet has a stronginfluence on the surfacefinish of the workpiecee and material removal rateWaviness[ m m]4.86420 120 240 360 480 600Traverse speed [mm/min]Figure 5. Parameter influence on the waviness [10]EXPERIMENTAL INVESTIGATIONSThe aim of o this study was to investigateeinfluence of traverse speedd on the appearance ofprofile waviness on machined surface. Theexperiments were conducted using a Byjet 40222abrasive water jet cutting machine (Bystronic AG,Switzerland). Aluminium A alloy AA-ASTM 60600(EN: AW-6060; ISO: AlMgSi) was used as aworkpiece material. Aluminum and its alloys arecharacterized by b high reflectivity and thermalconductivity. This makes them relatively difficult tocutwith lasers. Therefore, the machining withabrasive water jet is much more acceptable foraluminium alloy.Abrasive water w jet cutting involves a largenumber of variables that affect the cutting resultss(kerf width, taper and surface roughness, waviness).In the present study, s the influence of the followingparameters was investigated: traversee speed (thespeed at which the cutting head moves alongworkpiece during cutting operation) and materialthickness. The other process parameters were keptconstant using the standardd machine configurationn(d 0 =0.3mm;d A =1.02mm;p=380MPa;Q= =350g/min).The samples of aluminum alloy 6 and 10mmmthick were cut with different traverse speedssV= =(200, 300, 400, 4 500, 800 i 1000 mm/min). Onsuch machinedd samples, length at which the tenwaves were observed, was measured, Figure 6.13 th International Conference on Tribology – Serbiatrib’13219