Understanding the reaction mechanism of in-situ synthesized (TiC-TiB2)/AZ91 magnesium matrix composites

► For the first time, MMC of Mg/(TiCx-TiB2 network) is fabricated without using Al. ► A practical and cost-effective in-situ reactive infiltration technique is developed. ► The effect of the infiltrated Mg on the reaction between Ti and B4C is uncovered. ► The first attempt to study the effect of MgH2 on the reaction mechanism. ► The formation of the Ti2AlC ternary compound and its consequences are discussed.