TY - JOUR

T1 - Microstructure and degradation performance of biodegradable Mg-Si-Sr implant alloys

AU - Gil-Santos, Andrea

AU - Marco, Iñigo

AU - Moelans, Nele

AU - Hort, Norbert

AU - Van der Biest, Omer

PY - 2017/2/1

Y1 - 2017/2/1

N2 - In this work the microstructure and degradation behavior of several as-cast alloy compositions belonging to the Mg rich corner of the Mg-Si-Sr system are presented and related. The intermetallic phases are identified and analyzed describing the microstructure evolution during solidification. It is intended in this work to obtain insight in the behavior of the ternary alloys in in vitro tests and to analyze the degradation behavior of the alloys under physiologically relevant conditions. The as-cast specimens have been exposed to immersion tests, both mass loss (ML) and potentiodynamic polarization (PDP). The degradation rate (DR) have been assessed and correlated to microstructure features, impurity levels and alloy composition. The initial reactions resulted to be more severe while the degradation stabilizes with time. A higher DR is related with a high content of the Mg17Sr2 phase and with the presence of coarse particles of the intermetallics Mg2Si, MgSiSr and MgSi2Sr. Specimens with a higher DR typically have higher levels of impurities and alloy contents.

AB - In this work the microstructure and degradation behavior of several as-cast alloy compositions belonging to the Mg rich corner of the Mg-Si-Sr system are presented and related. The intermetallic phases are identified and analyzed describing the microstructure evolution during solidification. It is intended in this work to obtain insight in the behavior of the ternary alloys in in vitro tests and to analyze the degradation behavior of the alloys under physiologically relevant conditions. The as-cast specimens have been exposed to immersion tests, both mass loss (ML) and potentiodynamic polarization (PDP). The degradation rate (DR) have been assessed and correlated to microstructure features, impurity levels and alloy composition. The initial reactions resulted to be more severe while the degradation stabilizes with time. A higher DR is related with a high content of the Mg17Sr2 phase and with the presence of coarse particles of the intermetallics Mg2Si, MgSiSr and MgSi2Sr. Specimens with a higher DR typically have higher levels of impurities and alloy contents.

KW - Corrosion layer

KW - Impurities

KW - Intermetallics

KW - Magnesium alloys

KW - Microstructure

KW - Physiological degradation

KW - Engineering

UR - http://www.scopus.com/inward/record.url?scp=84992109339&partnerID=8YFLogxK

U2 - 10.1016/j.msec.2016.09.056

DO - 10.1016/j.msec.2016.09.056

M3 - Journal articles

C2 - 27987705

AN - SCOPUS:84992109339

VL - 71

SP - 25

EP - 34

JO - Materials Science and Engineering C

JF - Materials Science and Engineering C

SN - 0928-4931

ER -