Magnesium-based
materials show great potential for producing biodegradable stents, but
their high corrosion rates are a roadblock.
This
study investigates whether ultrasound melt treatment can change the
corrosion response of an extruded AZ91D-1.0%Ca (wt.%) in Earle's
Balanced Salt Solution by tailoring the intermetallics' morphology in
the as-extruded state.
The results showed that the
wires from ultrasound-treated ingots corroded faster than non-treated
ones in immersion for up to 6 hours. This trend shifted for longer
periods, and ultrasound-treated material showed lower corrosion rates
and uniform corrosion, while the non-treated material displayed
localized corrosion signs. Tensile testing of the wires demonstrated
that immersion in EBSS lowered the tensile strength and elongation at
fracture due to material degradation, regardless of the processing
route. Nonetheless, this decline was sharper in the non-treated
material.
These findings suggest that ultrasound
melt processing can be a promising method for improving the corrosion
resistance of magnesium-based materials, paving the way for their use in
manufacturing biodegradable stents.
Keywords
Magnesium; Ultrasound treatment; Stent; Corrosion; Mechanical properties
