Oraby, Ahmed HamedAhmed HamedOrabyChen, Hou-JenHou-JenChenHSIN-CHIH LINYoshitake, TsuyoshiTsuyoshiYoshitakeAhmed, Abdelrahman ZkriaAbdelrahman ZkriaAhmed2026-02-092026-02-092026-01-1509258388https://www.scopus.com/record/display.uri?eid=2-s2.0-105027036883&origin=resultslisthttps://scholars.lib.ntu.edu.tw/handle/123456789/735871Corrosion-resistant coatings are essential for extending the service life of magnesium alloys. In this work, quenched-produced diamond (Q-dia) films were deposited on Mg-Ca alloy substrates by physical vapor deposition using high-purity graphite (99.999 %) as the carbon source. To enhance interfacial bonding, three thin interlayers (Al, Ti, and TiC) were examined as interfacial layers. Among them, the TiC interlayer effectively enabled successful adhesion and produced a uniform coating. Scanning electron microscopy (SEM) revealed dense nanodiamond grains growth with a compact, a defect-free cross section. Electrochemical analyses demonstrated that Q-dia coatings markedly enhanced the corrosion resistance of Mg-Ca alloy in 3.5 wt% NaCl solution, increasing the corrosion resistance from 0.336 kΩ.cm² to 1.78 kΩ.cm². This enhancement is attributed to the highly compact microstructure of Q-dia grains containing both sp2- and sp3 hybridized -carbon phases, as confirmed by Raman spectroscopy. These findings highlight Q-dia as promising protective coating films for improving the corrosion resistance and durability of magnesium-based alloys.trueCorrosion resistanceElectrochemical analysisMg-Ca alloyNanodiamondPhysical vapor depositionjournal article10.1016/j.jallcom.2025.1858882-s2.0-105027036883