Novel Technique of Laser Through-Hole Drilling in Teflon

Abstract

A method is presented to accelerate the convergence of finite-lattice sequences to their bulk limit. The calculation of highly accurate estimates of the critical parameters of the bulk system is then possible. Applied to the Hamiltonian version of the 2 3 model (three-state Potts model) in (1 + 1) dimensions, these techniques yield estimates for the exponents -y=1.444*0.001, U-0.8333iO.0003 and a =0.33*0.01. For theZ5model, the presence of a Kosterlitz-Thouless transition is confirmed.

An experimental study of drilling small and deep blind holes with an abrasive water jet

“…where constant C is a proportional factor, P w is water pressure, _ m m w is the water flowrate, _ m m a is the abrasive mass flowrate, d nozzle is the collimating nozzle diameter and u is cutting speed. The value of N m for any material can be determined by measuring the depth of cut at different values of AWJ machining parameters and by using equation (2). According to data provided in reference [16], the machinability numbers for materials used in the presented case are given in Table 4.…”

“…In many applications the desired property of holes is that the surface of the hole should be without a heat-affected zone (HAZ). Most of processes used for drilling, such as conventional micro-hole drilling [1], laser beam machining (LBM) [2,3], electron beam machining [4] and electrical discharge machining (EDM) [5,6] produce an HAZ on the surface and require special techniques for reducing it. The only known nonconventional processes, which do not produce any significant HAZ, are the abrasive water jet (AWJ) [7] and electrochemical machining (ECM) [8].…”

Comparison of the modeling and experimental data of the laser drilled microhole profiles in carbon fiber composites in low fluence regime

“…Most experimental works [2][3][4][5][6][7][8][9][10][11][12][13][14][15] confirm that the laser ablation for polymers and fiber reinforced composites obeys the simple Beer's law, there are several publications to establish simple models for the ablation rate with modified Beer's law [15,. Although occasionally there are conical [44], domelike [7,[45][46], trapezoidal or V [6] shaped holes reported, only Olson and Swope [14] calculated the Gaussian beam drilling hole profiles, however their model is restricted to only one pulse and can not explain the stabilized hole formation which is observed in this paper in the low fluence regime regarded as less than 10 J/cm 2 . In this paper, not only a new simple method to model drilling hole profiles is presented but also the reason of stabilized hole formation is explained for polymers and fiber reinforced composites under certain circumstances.…”

<title>Laser-drilled microhole profiles in fiber-reinforced composites</title>

“…Although occasionally there are conical [31], domelike [7,[32][33], trapezoidal or V [8] shaped holes reported, only Olson and Swope [16] calculated the Gaussian beam drilling hole profiles, however their model is restricted to only one pulse and can not explain the stabilized hole formation in thelow fluence regime. A simple method to model drilling hole profiles was presented in previous publications [1 -2].…”