Processing of a Novel Zn Alloy Micro-Tube for Biodegradable Vascular Stent Application

Evolution of the in vitro degradation of Zn–Mg alloys under simulated physiological conditions

“…In that sense, the addition of physiological relevant elements may bring an added value in terms of biocompatibility. 12,13 Mg, for example, is an essential nutrient that supports important biological processes from which bone growth and development can be highlighted. 14 The addition of Mg provided Zn-Mg alloys with a maximum strength and elongation for Mg contents around 1 wt%.…”

Review on Advances in Metal Micro-Tube Forming

“…Recent developments in the fabrication of micro-tubes aim in particular to provide improved semi-finished products, with more economic manufacturing processes, for use in microsystem-based applications of medical engineering and microfluidics for heat exchangers. When primarily considering the fabrication of seamless metallic tubes, the investigated technologies can be divided into (a) dieless drawing techniques [5,[21][22][23][24][25][26][27][28][29][30][31][32][33][34][35], (b) process chains, applying scaled-down and partly modified tube drawing [36][37][38][39][40][41][42][43][44][45][46][47], and (c) manufacturing techniques of grooved micro-tubes for applications in heat exchange [43,[48][49][50][51][52][53][54]. Apart from this research into tube manufacturing processes, notable progress was also achieved in the design of the process and tools for the profile extrusion of tubular micro-profiles with a number of channels [55][56][57][58][59].…”

“…Research into process chains using scaled-down tube drawing processes focused in large part on the processing of degradable biomedical metallic materials, such as alloys based on magnesium [36,[39][40][41]44] or zinc [38], as shown in Table 3. These alloys have attracted extensive attention as materials for metallic stents for the treatment of cardiovascular disease, since there is no requirement for a secondary removal surgery.…”

“…However, the drawbacks of the mandrel drawing of micro-tubes consist in difficulties relating to the removal of the mandrel from the drawn tube and a lower surface quality, compared to that of drawing with fixed plugs [46]. Investigations into the use of a novel biodegradable zinc alloy for stent fabrication were documented in [38]. The developed process chain consisted of drilling an extruded billet, several cold-rolling operations, and multi-pass drawing, without and with mandrel.…”

“…The developed process chain consisted of drilling an extruded billet, several cold-rolling operations, and multi-pass drawing, without and with mandrel. Each forming operation was followed by a heat treatment process of the components, and an average grain size of 20 µm was attained, with a dimensional accuracy for the final tubes below 3.8% [38]. The mechanical properties and corrosion behavior were determined, and prototypes of the stents were tested mechanically.…”