Machining of stent-like geometries in thin NiTi sheets using water jet cutting

Frotscher, M.¹; Gugel, H.¹; Neuking, K.¹; Theisen, W.¹; Eggeler, G.¹; Kahleyß, F.^{2, a}; Biermann, D.^{2, b}

1)

Institut für Werkstoffe, Ruhr-Universität Bochum, 44801 Bochum

2)

Institut für Spanende Fertigung, Technische Universität Dortmund, Baroper Str. 301, 44227 Dortmund

a) kahleyss@isf.de; b) biermann@isf.de

Kurzfassung

Abrasive water jet cutting has been used for difficult-tomachine materials for some years. The abrasive particles are entrained into the water jet, which impinges onto the work piece. Erosion processes remove the material, which is fully penetrated by the jet. High pressure water jet machining features good cutting quality, flexibility and cost effectiveness, when compared to traditional thermal cutting methods, such as laser cutting. Sequential machining is minimized and it is an environmentally friendly process, because no gases or vapors are produced. Machined parts are practically free of burrs and no heat affected zones (HAZ) are formed. Nearly all kinds of materials can be cut economically up to thicknesses of 100 mm and there is a wide range of applications. As a result, water jet machining is an established alternative cutting method for the processing of thick sheets. However, it is widely accepted that metallic foils or very thin sheets can not be cut by water jet. In the present paper, we report on the water jet machining of stent-like geometries in thin NiTi sheets. The influence of performance parameters such as traverse speed, pump pressure, abrasive mass flow rate, orifice diameter, and focussing nozzle diameter are discussed.

Schlüsselwörter

NiTi shape memory alloys, water jet machining, microstructure, pseudoelasticity, stents

Veröffentlichung

In: Medical Device Materials V, Proceedings from the Materials & Processes for Medical Devices Conference, 10.8.-12.8. 2009, Minneapolis, Minnesota, USA, Gilbert, J. (Hrsg.), S. 201-206