Surface Preparation of CpTi G4 Discs

A CpTi G4 rod with a diameter of 10 mm (Bibus Metals, Dąbrowa, Poland) was cut into disk-shaped samples which were 5 mm high. CpTi G4 disks were mechanically pre-polished on 600 to 5000 # grit SiC papers. A colloidal silica suspension with a grain size of 0.04 µm (OP-S suspension, Struers, Cleveland, OH, USA) was used in the final step of the mechanical polishing. Samples with a mirror surface were cleaned in an ultrasonic cleaner for 20 min in acetone, and then in ultrapure water with a resistivity of 18.2 MΩ cm at 25 °C, produced with a Milli-Q^® Advantage A10 Water Purification System (Millipore SAS, Molsheim, France). The polished CpTi G4 samples were sandblasted with a white Al₂O₃ FEPA Grit F220 abrasive [27 ]. Next, they were sonicated again. After drying, the samples were autoclaved using the Zealway Model GR60 DA (Xiamen, China). A detailed description of the conditions of the sandblasting and autoclaving process is given in the earlier work [28 (link)].