Abrasive waterjet micro-machining of channels in metals: Model to predict high aspect-ratio channel profiles for submerged and unsubmerged machining

Abstract Recent advances in the development of miniaturized nozzles have made possible the use of abrasive waterjets to perform controlled-depth micro-milling. Haghbin et al. (2015) discussed the effects of the surrounding fluid in the micro-machining of shallow channels in 316L stainless steel and 6061-T6 aluminum using a prototype nozzle having an orifice diameter of 127 μm and a 254 μm mixing tube diameter. This paper uses those results to develop a new surface evolution model that predicts the size and shape of relatively deep micro-channels resulting from unsubmerged and submerged abrasive water jet micro-machining (AWJM). For both unsubmerged and submerged AWJM, and for both materials, the erosive efficacy distribution changed suddenly after the initial formation of the channel. The initially wide distribution was due to backflow of the abrasive slurry along the channel walls, which did not occur once the channel was formed and most of the flow was directed along the channel length. A novel approach in which two different erosive efficacy expressions are sequentially used in a surface evolution equation is presented and shown to accurately predict the evolving surface topography for micro-channels up to aspect ratios of 3.

[1]  S. Crow.  A THEORY OF HYDRAULIC ROCK CUTTING , 1973 .

[2]  Andreas Manz,et al.  Microfluidics: Applications for analytical purposes in chemistry and biochemistry , 2008, Electrophoresis.

[3]  Jan K. Spelt,et al.  Prediction of machined surface evolution in the abrasive jet micro-machining of metals , 2012 .

[4]  Jun Wang,et al.  The Cutting Performance in Multipass Abrasive Waterjet Machining of Industrial Ceramics , 2003 .

[5]  Mihael Junkar,et al.  Simulation of abrasive water jet cutting process: Part 1. Unit event approach , 2004 .

[6]  Adib A. Becker,et al.  Finite element modelling of abrasive waterjet milled footprints , 2013 .

[7]  Dragos Axinte,et al.  Geometrical modelling of abrasive waterjet footprints: A study for 90° jet impact angle , 2010 .

[8]  A. Bhagat,et al.  Enhanced particle filtration in straight microchannels using shear-modulated inertial migration , 2008 .

[9]  J. K. Spelt,et al.  Surface evolution models for abrasive slurry jet micro-machining of channels and holes in glass , 2014 .

[10]  Jan K. Spelt,et al.  Abrasive jet micromachining of acrylic and polycarbonate polymers at oblique angles of attack , 2008 .

[11]  J. K. Spelt,et al.  Surface evolution models for abrasive jet micromachining of holes in glass and polymethylmethacrylate (PMMA) , 2007 .

[12]  J. K. Spelt,et al.  Abrasive jet micromachining of polymethylmethacrylate , 2007 .

[13]  I. R. Pashby,et al.  Characteristics of the surface of a titanium alloy following milling with abrasive waterjets , 2005 .

[14]  Jun Wang,et al.  Predictive depth of jet penetration models for abrasive waterjet cutting of alumina ceramics , 2007 .

[15]  Alberto Carrascal,et al.  Evolutionary Industrial Physical Model Generation , 2010, HAIS.

[16]  Jan K. Spelt,et al.  Surface evolution models in abrasive jet micromachining , 2008 .

[17]  Dragos Axinte,et al.  Mathematical modelling of abrasive waterjet footprints for arbitrarily moving jets: Part II—Overlapped single and multiple straight paths , 2013 .

[18]  G. Rehbinder.  A theory about cutting rock with a water jet , 1980 .

[19]  L. N. López de Lacalle,et al.  Effect of process parameter on the kerf geometry in abrasive water jet milling , 2010 .

[20]  Y. Oka,et al.  The impact angle dependence of erosion damage caused by solid particle impact , 1997 .

[21]  Dragos Axinte,et al.  Mathematical modelling of abrasive waterjet footprints for arbitrarily moving jets: Part I—single straight paths , 2012 .

[22]  Jan K. Spelt,et al.  Abrasive waterjet micro-machining of channels in metals: Comparison between machining in air and submerged in water , 2015 .