R. Kovacevic et al., ACOUSTIC-EMISSION SENSING AS A TOOL FOR UNDERSTANDING THE MECHANISMS OF ABRASIVE WATER-JET DRILLING OF DIFFICULT-TO-MACHINE MATERIALS, Proceedings of the Institution of Mechanical Engineers. Part B, Journal of engineering manufacture, 212(1), 1998, pp. 45-58
For drilling difficult-to-machine materials, abrasive water jet (AWJ)
drilling provides several advantages not offered by other machining me
thods, such as the capability to achieve higher depth-diameter ratios,
the absence of a heat-affected zone, and no thermal distortion. An ac
oustic emission (AE) sensing technique is used to study the material r
emoval mechanisms involved in the AWJ drilling process. The feasibilit
y of using r.m.s. acoustic emission (AE(RMS)) to monitor the AWJ drill
ing depth on-line is also investigated. Stochastic modelling of the ti
me domain AE signal provides more insight into the physics of the proc
ess.