On geometrical accuracy and integrity of surfaces in multi-mode abrasive waterjet machining of NiTi shape memory alloys

NiTi shape memory alloys are largely employed in the manufacture of high-tech products (e.g. medical, aerospace, sensing). This research reports on the use of multi-mode (i.e. through cutting, countersinking and milling) abrasive waterjet machining of NiTi by investigating the influence of process parameters on the integrity and geometrical accuracy while taking into consideration the secondary temperature and mechanical induced transformations in the workpiece material. The research proved that AWJ machining, if optimally conducted, can generate surfaces that can fulfill the quality requirements (e.g. cut surface: roughness <4 mu m; countersunk hole: circularity <0.04 mm, concentricity <0.15 mm: milled surface: roughness <5 mu m) to make them used for manufacturing parts for the aerospace industry. (C) 2013 CIRP.