Thermal Energy Distributions in the Workpiece During Cutting With an Abrasive Waterjet

Abstract

Distribution of thermal energy in the workpiece during cutting with an abrasive waterjet (AWJ) was studied experimentally. Detailed time-temperature measurements in the workpiece as a function of jet pressure, traverse rate, workpiece material, and workpiece orientation were performed. It is shown that maximum temperatures occur at the immediate vicinity of the cutting interface and sharply decay thereafter with increasing distance from the interface. A higher jet pressure and/or a lower traverse speed results in higher temperatures in the workpiece. A material with higher thermal conductivity experiences higher temperatures during the cut. Within the workpiece, higher temperatures occur at inner zones where the jet-induced cooling effects are minimum.

Response of titanium aluminide alloy to abrasive waterjet cutting: Geometrical accuracy and surface integrity issues versus process parameters

“…It has been claimed that the predominant factors in a case formation are the presence of oxygen, exposure time, and the temperature [26]. The exposure time in the present (abrasive) cutting is very short (on the order of fractions of a second as such phenomena occur at the grit-workpiece interface); there is no information about the temperature measurement on TiAl alloys in AWJ cutting although there has been a report on a temperature measure-ment on Al alloy of 45 C at a pressure of 379 MPa (55 kpsi) in AWJ cutting [27]. It has also been claimed that the temperature distributions of a struck material surface showed the impingement by fine particles would result in a maximum striking temperature of up to 1200 C followed by rapid cooling [28].…”

Method for online quality monitoring of AWJ cutting by infrared thermography

“…Photoelastic study was performed on transparent birefringent material by Ramulu [2], who identified two distinctive processes: microcracking due to pure water jet and microcrack nucleation and micromachining due to abrasive action. AWJ machining thermal distribution on workpiece was first measured by Ohadi et al [3], who inserted a matrix of thermocouples in the lateral workpiece surface and bottom surface regarding to the traverse direction of the cutting head movement. It was shown that temperature peaks rose up to 70 8C and found out that caution should be paid when generalizing AWJ as a cold process.…”

Rock cutting by abrasive water jet: an energy approach

“…Another advantage was the possibility of cutting with low temperatures, avoiding thermal stress. Ohadi et al (1992) performed tests to evaluate the thermal energy distribution in specimens cut with an abrasive waterjet. They measured the temperature at several locations and observed a maximum temperature of T -T 0 = 75ºC, where T is the measured temperature and T 0 is the room temperature.…”

“…In contrast, Chao & Geskin (1993) state that the striations are a result of disturbances such as machine vibrations due to the unsteady removal mechanism, which is a characteristic of WJ and AWJ cutting systems. Hashish (1992) claims that among the theories which discuss the surface roughness generated by WJ and AWJ cutting, some hypotheses can be made: waviness may be a result inherent to the cutting process itself, in which case, all process parameters will quantitatively affect the geometry; it may also be due to dynamic parameter fluctuations (or unsteadiness) as in pressure, abrasive flow rate and traverse rate. Gärdek & Boubker (2015) state that roughness can be reduced when higher pump pressures and higher abrasive mass flow rates are applied.…”

“…As indicated before, the smooth cut depth is h and the total thickness is h MAX . The ratio between the top and the bottom widths is called taper (HASHISH, 1992). Momber (1995) observed the formation of large pockets in the very lower region of the cuts in soft concrete materials subjected to an AWJ.…”