A sintered body of TiB₂-reinforced iron matrix composite (Fe-TiB₂) is fabricated by pressureless-sintering of a mixture of titanium hydride (TiH₂) and iron boride (FeB) powders. The powder mixture is prepared in a planetary ball-mill at 700 rpm for 3 h and then pressurelessly sintered at 1300, 1350 and 1400°C for 0-2 h. The optimal sintering temperature for high densities (above 95% relative density) is between 1350 and 1400°C, where the holding time can be varied from 0.25 to 2 h. A maximum relative density of 96.0% is obtained from the (FeB+TiH₂) powder compacts sintered at 1400°C for 2 h. Sintered compacts have two main phases of Fe and TiB₂ along with traces of TiB, which seems to be formed through the reaction of TiB₂ formed at lower temperatures during the heating stage with the excess Ti that is intentionally added to complete the reaction for TiB₂ formation. Nearly fully densified sintered compacts show a homogeneous microstructure composed of fine TiB₂ particulates with submicron sizes and an Fe-matrix. A maximum hardness of 71.2 HRC is obtained from the specimen sintered at 1400°C for 0.5 h, which is nearly equivalent to the HRC of conventional WC-Co hardmetals containing 20 wt% Co.

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• Effect of Ce Addition on the As-Cast and As-Forged Microstructure of Fe-TiB2 Composites
  Lin Zhang, Jianwen Gao, Minghao Huang, Engang Wang
  JOM.2019; 71(11): 4144.     CrossRef
• Microstructure, mechanical, and tribological properties of pressureless sintered and spark plasma sintered Fe TiB2 nanocomposites
  Hak-Rae Cho, Ji-Soon Kim, Koo-Hyun Chung
  Tribology International.2019; 131: 83.     CrossRef