en <span style="font-size:11pt"><span style="line-height:200%"><span style="font-family:Calibri,sans-serif"><span new="" roman="" style="font-family:" times=""><span style="background-color:#ffffff;">In this study, for the first time, the Forsterite (Mg</span>_{<span style="background-color:#ffffff;">2</span>}<span style="background-color:#ffffff;">SiO</span>_{<span style="background-color:#ffffff;">4</span>}<span style="background-color:#ffffff;">) nanoparticles (NPs) with the size of about 25 nm were added to the phosphate-based electrolyte, and the characteristics and properties of the obtained plasma electrolytic oxidation (PEO) coating on AZ31 Mg alloy was investigated. The results of the potentiodynamic polarization measurements revealed that after </span><span style="background:yellow"><span style="background-color:#ffffff;">one</span></span><span style="background-color:#ffffff;"> week of exposure to simulated body fluid (SBF) solution, the coating with </span><a name="_Hlk83102482"><span style="background-color:#ffffff;">Mg</span>_{<span style="background-color:#ffffff;">2</span>}<span style="background-color:#ffffff;">SiO</span>_{<span style="background-color:#ffffff;">4</span>}<span style="background-color:#ffffff;"> NPs </span></a><span style="background-color:#ffffff;">possessed 12.30 kΩ cm</span>^{<span style="background-color:#ffffff;">2</span>}<span style="background-color:#ffffff;"> polarization resistance</span><span style="background:yellow"><span style="background-color:#ffffff;">,</span></span><span style="background-color:#ffffff;"> which was more than </span><span style="background:yellow"><span style="background-color:#ffffff;">two</span></span><span style="background-color:#ffffff;"> times greater than that of the coating without NPs. The thicker coating layer, lower wettability, and also presence of Mg</span>_{<span style="background-color:#ffffff;">2</span>}<span style="background-color:#ffffff;">SiO</span>_{<span style="background-color:#ffffff;">4</span>}<span style="background-color:#ffffff;"> NPs inside the pores were responsible for enhanced corrosion protection in the Mg</span>_{<span style="background-color:#ffffff;">2</span>}<span style="background-color:#ffffff;">SiO</span>_{<span style="background-color:#ffffff;">4</span>}<span style="background-color:#ffffff;"> NPs incorporated coating. After </span><span style="background:yellow"><span style="background-color:#ffffff;">three</span></span><span style="background-color:#ffffff;"> weeks of immersion in SBF solution, </span><span style="color:black"><span style="background-color:#ffffff;">the in-</span></span><span style="color:black"><span style="background-color:#ffffff;">vitro bioactivity test results </span><span style="background:yellow"><span style="background-color:#ffffff;">indicated the</span></span><span style="background-color:#ffffff;"> ability of </span><span style="background:yellow"><span style="background-color:#ffffff;">the NPs-containing coating to form apatite (Ca/P ratio of 0.92) was weaker than the coating without NPs (Ca/P ratio of 1.17)</span></span><span style="background-color:#ffffff;">. </span><span style="background:yellow"><span style="background-color:#ffffff;">This could be attributed to the lower wettability of the coating with NPs and supports that the addition of the nanoparticles is not beneficial to the bioactivity performance of the coating.</span></span><span style="background-color:#ffffff;">&nbsp;</span></span></span></span></span></span> ,AZ31 Mg alloy,plasma electrolytic oxidation (PEO),Forsterite (Mg2SiO4),corrosion,bioactivity. 1 16 http://ijmse.iust.ac.ir/browse.php?a_code=A-10-488-12&slc_lang=en&sid=1 Amirhossein Kazemi amirhosseinkazemin1993@gmail.com 1800319475328460014857 1800319475328460014857 No Department of Materials Engineering, Bu-Ali Sina University, Hamedan 65178-38695, Iran Arash Fattah-alhosseini arash.fattah@gmail.com 1800319475328460014858 1800319475328460014858 Yes Department of Materials Engineering, Bu-Ali Sina University, Hamedan 65178-38695, Iran Maryam Molaei m.molaie93@yahoo.com 1800319475328460014859 1800319475328460014859 No Department of Materials Engineering, Bu-Ali Sina University, Hamedan 65178-38695, Iran Meisam Nouri pasdasht@gmail.com 1800319475328460014860 1800319475328460014860 No Department of Materials Engineering, Bu-Ali Sina University, Hamedan 65178-38695, Iran