Characterization of microstructure and composition of plasma electrolytic oxide film formed on az31 mg alloy

Efrina Hidayati, Anawati Anawati

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review


Magnesium alloy has been widely investigated as a biodegradable implant material owing to its unique properties to degrade spontaneously in human body fluid without causing toxicity. However, the degradation rate needs to be controlled. An effective way to lower down the degradation rate of Mg alloy is by coating with plasma electrolytic oxidation (PEO) technique. In this research, the microstructure and mechanical hardness of the PEO film formed on AZ31 were investigated. The film was prepared under a constant current of 400 A/m2 in the Na3PO4 solution at 30°C. The voltage-time curve showed an immediate increase of current during the first 25 s before reaching a steady-state voltage of 150 V. The spark discharge revealed as white micro discharges. The film formed for 3 min exhibited a high surface roughness with a large variety of thickness in the range of 1-20 µm. The film contained pores and cracks. The big pores with diameter size 10-20 µm were formed as a result of gas entrapment, while the small pores with a radius of 1-3 µm were associated with the discharge tunnel during the PEO process. The X-ray diffraction pattern indicated that the film composed of crystalline Mg3(PO4)2.

Original languageEnglish
Title of host publicationPhysics Symposium
Subtitle of host publicationKey Research in Materials Science
EditorsAyi Bahtiar, Togar Saragi, Sahrul Hidayat, Lusi Safriani
PublisherTrans Tech Publications Ltd
Number of pages5
ISBN (Print)9783035716979
Publication statusPublished - 2020
Event4th Padjadjaran International Physics Symposium, PIPS 2019 - Bandung, Indonesia
Duration: 13 Nov 201914 Nov 2019

Publication series

NameKey Engineering Materials
Volume860 KEM
ISSN (Print)1013-9826
ISSN (Electronic)1662-9795


Conference4th Padjadjaran International Physics Symposium, PIPS 2019


  • Hardness
  • Magnesium
  • Microstructure
  • PEO


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