Bonding properties and corrosion resistance of TaC-Fe enhanced layer on GCr15 surface prepared by in-situ hot pressing

Abstract

In this paper, high-hardness and corrosion-resistant TaC-Fe reinforced layer was prepared on GCr15 surface by in-situ hot pressing method using GCr15 and high-purity tantalum plate as raw materials. Phase compositions, microstructures, nanohardness values, elastic moduli, bonding properties, and corrosion resistances of the reinforcement layers were studied by various analytical methods. Results suggested that reinforcement layer prepared by in-situ hot pressing diffusion increased layer thickness as a function of holding time. Layer thicknesses at 1000 ℃ temperature, 40 MPa pressure, and holding times of 1, 2, 3, 4, and 5 h were estimated to 6.34 ± 0.69 µm, 6.92 ± 0.75 µm, 12.25 ± 0.68 µm, 12.29 ± 0.91 µm, and 14.75 ± 0.89 µm, respectively. The composition was identified as TaC. Nanohardness and elastic modulus of TaC-Fe reinforced layer were measured as 33.93 GPa and 627.51 GPa, respectively. Obtained TaC-Fe reinforced layer showed good metallurgical bond to GCr15 with bonding force exceeding 100 N. Corrosion rate (CR) of TaC-Fe enhanced layer in electrolyte solution was evaluated as only 19% of that of GCr15 with protection efficiency (Pe) of 81%, useful for protecting substrate GCr15 from deep corrosion. In sum, TaC-Fe enhanced layer possessed good protective effects on GCr15.