Fabrication of small size inner spiral ribbed copper tube by fluid mandrel drawing

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].…”

“…A conventional method-described in the corresponding literature as a spinning process-to manufacture grooved tubes, with outer diameters above 5 mm, consists in applying pressure using rotating steel balls on a tubular blank, which is supported inside with a ripped plug and drawn additionally in the axial direction [49,50]. However, similar to the plug drawing of smooth tubes, this method is limited to tube outer diameters above 4-6 mm due to difficulties in fabricating the plug and in its handling [53].…”

“…Within certain limits, smaller diameters can be achieved by applying multi-pass tube sinking to a grooved tube, fabricated by the spinning process, described above [50,51,53]. However, this method is limited, because the ratio of the width of grooves to the width of the ribs reduces with each drawing pass, and after a certain number of passes, the grooves are closed by the deformed ribs [49,53]. Furthermore, an excessive increase in the wall thickness could be observed [49,53].…”

“…However, this method is limited, because the ratio of the width of grooves to the width of the ribs reduces with each drawing pass, and after a certain number of passes, the grooves are closed by the deformed ribs [49,53]. Furthermore, an excessive increase in the wall thickness could be observed [49,53]. Investigations into drawing such grooved tubes with a liquid medium inside-according to fluid mandrel drawing [45]-have shown that these drawing limits of tube sinking could be extended considerably [43,49].…”

3D FEM validation of ultra-small inner spiral ribbed copper tube using the tube sinking method

“…The manufactured tube is further improved by applying pressure from steel sphere balls on the tube with an outer ribbed spiral surface mandrel inside. This development increases the production speed of the manufacturing process [8]. This research related to the development of ultra-small inner spiral ribbed copper tubes (ISRCTs) with high-quality heat transfer.…”