Microstructural Evolution and Bio-Corrosion Behavior of a CP-Ti Processed by Multi-Pass of Severe Plastic Deformation

• Published in: JOM (1989) 2022-12, Vol.74 (12), p.4621-4631
• Main Authors: Vakili-Azghandi, Mojtaba, Famil Hatami, Mohammad, Hoseini Sabzevari, Seyed Amir, Moosavi Nezhad, S. M., Mandanipour, Valiollah, Szpunar, Jerzy A.
• Format: Article
• Language: English
• Subjects: Chemistry/Food Science; Cooling; Corrosion resistance; Corrosion tests; Deformation; Earth Sciences; Electron back scatter; Engineering; Environment; Friction stir welding; Grain boundaries; Grain refinement; Grain size; Heat resistance; Interactions between Biomaterials and Biological Tissues and Cells; Investigations; Mechanical properties; Microhardness; Microscopy; Microstructure; Morphology; Optical microscopy; Phase transitions; Physics; Plastic deformation; Software; Temperature; Titanium; Titanium alloys; Widmanstatten structure
• ISSN: 1047-4838; 1543-1851
• DOI: 10.1007/s11837-022-05415-9

The microstructure evaluation and phase transformation of multi-pass friction stir-processed (FSP) commercially pure titanium were investigated using optical microscopy, scanning electron microscopy equipped with a backscatter detector, and electron backscatter diffractometer. The microstructure characterization shows that the grain refinement mechanism changed with the increasing number of passes. The equiaxed α grains in the untreated sample changed to lath-shaped grains surrounded by serrated grain boundaries, and produced Widmanstätten morphology during the cooling cycle of FSP. The higher micro-hardness values and bio-corrosion resistances of the FSP-treated samples are due to their lower grain size compared to the untreated samples. Furthermore, the presence of lath-shaped Widmanstätten morphology shows a higher micro-hardness value and lower bio-corrosion resistance.