Nickel-titanium（Ni-Ti）shape memory alloys are often used as stent materials. This study assessed application of magnetic polishing for crown-like［as part of mesh tube］ and coil-shaped memory alloys. The final goals of this study are to remove naturally formed oxide generated on Ni-Ti shape memory alloy surfaces having complex shapes and to conduct surface polishing with average roughness of tens of nanometers. Removal of naturally formed oxide films and surface polishing with roughness of tens of nanometers were accomplished, but surface scratch damage occurred sometimes.
Wear resistance testing of the anodic oxide coating on aluminum and its alloys is specified in the Japanese Industrial Standard（JIS）. Based on JIS, the abrasive-wheel-wear abrasion resistance test for a hard anodic oxide coating is applied only to a plate-shaped sample（JIS H 8682-1:2013）. However, because the test method is simple, this test is also applied to a nonplanar cylindrical sample at the production site. For this case, little technical information is openly available because the test is conducted independently at each manufacturer, regardless of the regulations. To collect technical information for this study, we applied the abrasive-wheel-wear abrasion resistance test for the nonplanar cylindrical sample. With increasing curvature of the nonplanar cylindrical sample, the abrasion resistance and the wear track width on abrasive paper were decreased linearly. These findings indicate that the contact area between the nonplanar cylindrical sample and abrasive paper plays an important role in abrasive-wheel-wear abrasion resistance. Based on these results, we provide a relation of abrasion characteristics for the plate-shaped and nonplanar cylindrical samples. For the nonplanar cylindrical sample, it is noted that the wear track becomes inhomogeneous with increase of the double stroke of the abrasion resistance test.