Surface evolution models in abrasive jet micromachining

A study of the flow characteristics in micro-abrasive jets

“…as a function of process and material variables [3][4][5][6][7][8][9]. For hard and brittle materials, the impact force of the abrasive particle causes localized cracks at the work surface.…”

“…Ciampini et al [5] studied the interference effects between an incident stream of spheres and those rebounding from a flat surface, and developed a computer model to examine the severity and frequency of interparticle collisions. Ghobeity et al [6] extended an existing erosion model to predict the cross-sectional profiles of unmasked micromachined channels in borosilicate, in which the experimentally obtained spatial and velocity distributions of particles in the jet of an AJM were used. In [6], particle velocity across a circular jet was measured using a phase-Doppler particle analyzer.…”

Solid particle erosion mechanisms of protective coatings for aerospace applications

“…As can be seen in Figure 5.3, wear scars generated from tests with cylindrical nozzles are axi-symmetrical and present a Gaussian type of profile. Ghobeity et al [177] found this type of profile to be the result of a radial linear decrease of velocity from a maximum value found at the center of the nozzle combined to a Weibull radial mass flux probability distribution function of the particles exiting the nozzle. Completing a full scan is very time consuming.…”

“…In the past 15 years, much work on the influence of process parameters on the shape of erosion scars has been done in the context of abrasion jet micromachining of glass for flat panel displays [69,71,167,[170][171][172][173][174][175][176][177][178][179][180][181]. In particular, the work of Papini, Spelt and coworkers [167,170,[174][175][176][177][178][179][180][181] has led to many interesting findings on the importance of working parameters such as feed rate and WD on the erosion process. As we will discuss in the next sections, the Gaussian profile of the wear scar has enabled us to measure the volume loss of eroded samples using a simple profilometry methodology and other results regarding particle interference effects have helped us to optimize our erosion testing methodology.…”

On impinging near‐field granular jets

“…where t c is determined using Equation (39). In a similar manner, the limiting time-step size for a grain-surface collision can also be calculated.…”