Abstract:

There is a growing demand for degradable membranes with sufficient mechanical properties to guide tissue regeneration in dental surgery. In the present work, a two-stage rolling process in which the first rolling stage (FRS) adopted a reduction rate of 30% for six passes at various temperatures, while the second rolling stage was rolling at 200 °C for two passes, was employed to prepare a 150 μm-grade Mg-2.0Zn-0.5Y-0.5Nd (ZE21B) Mg alloy sheets for guided tissue regeneration membrane. The microstructure of the thin sheets was gradually refined with increasing rolling passes, and the thin sheets that were rolled at different FRS temperatures exhibit an ellipse texture. The thin sheets rolled at 350 °C for FRS show low elongation due to premature fracture caused by the coarse second phase particles. On account of uniform and fine grains, the thin sheets rolled at 400 °C for the FRS have proper mechanical properties: yield strength of 214.6 ± 8.5 MPa, ultimate tensile strength (UTS) of 246.8 ± 10.3 MPa and elongation to failure of 28.3 ± 1.2%. When rolling at 450 °C for FRS, proper ductility of the thin sheets has been acquired, followed by a decline in UTS since a bimodal structure with fine and coarse grain was developed. Immersion tests demonstrated the FRS temperature had no significant effect on the corrosion behavior and corrosion rate of Mg alloy sheets after 7 days’ immersion in artificial saliva solution. This research has great significance for the production of degradable Mg sheets for guided tissue regeneration membrane.

Key words: Mg alloy thin sheets, Two-stage rolling, Guided tissue regeneration membrane, Artificial saliva, Corrosion behavior