Cold Crucible Induction Melting for the Fabrication of Fe–xTiC In Situ Metal Matrix Composites: Alloying Efficiency and Microstructural Analysis

Abstract

Fe–xTiC in situ metal matrix composites (MMCs) are fabricated utilizing a cold crucible inductive melting (CCIM) technique with varying TiC amounts (2, 3.5, and 5 wt%). Steel blocks and pure Ti plates are remelted in a water‐cooled copper crucible. The subsequent solidification of [Ti]‐ and [C]‐rich melt yields TiC reinforcement particles in an ingot. The holding time varies between 5 and 30 min, whereas the holding temperature alters depending on the amount of TiC, ranging from 1380 to 1620 °C for Fe‐5TiC and Fe‐2TiC, respectively. Alloying efficiency for TiC‐forming elements is estimated for all fabricated Fe–xTiC ingots by comparing [Ti] and [C] target values with measured ones. The lower TiC amounts and shorter holding times result in decreased [Ti] and [C] losses. SEM analysis of three cross‐section samples representing different TiC amounts reveals two distinct morphologies of TiC in situ reinforcements: primary blocky/cubic and eutectic plate‐like precipitates. The blocky precipitates appear slightly finer with a decrease in TiC amount (4.4 ± 1.2 μm for Fe‐5TiC and 3.8 ± 0.7 μm for Fe‐2TiC), whereas the length of plate‐like precipitates noticeably decreases in the samples with lower TiC amounts (11.0 ± 7.0 μm for Fe‐5TiC and 6.8 ± 3.6 μm for Fe‐2TiC).