Al₂O₃/MC particles reinforced MoFeCrTiWNb_x high-entropy-alloy coatings prepared by laser cladding

ABSTRACT

The Al₂O₃/MC particles reinforced MoFeCrTiW(Al₂O₃)_0.5Nb_x (x = 1, 1.5, 2, 2.5, and 3) high-entropy alloy coatings were successfully fabricated on the M2 high-speed steel by laser cladding. An investigation was carried out to assess the effect of the Nb on the microstructure and properties of coatings. The coatings are all composed of the BCC solid-solution phase, C14-Laves phase, and (Nb, Ti)C carbide plus a small amount of Al₂O₃. An increasing in Nb content results in the microstructural change from hypoeutectic to eutectic and the improvement in the hardness and wear resistance of the coating. When x = 3, the coating possesses the highest hardness (∼782 HV_0.2) and lowest wear volume loss (∼0.52 mm³). The dispersion strengthening and lamellar boundary strengthening play a dominating role in enhancing the hardness and wear resistance of coatings.

KEYWORDS:

• Laser cladding
• high-entropy alloy
• eutectic
• wear resistance
• in-situ
• microstructure
• microhardness

Additional information

Funding

This work was supported by the National Natural Science Foundation of China: [Grant Number (No.51965010)]; Talent Introduced of Guizhou University: [Grant Number (grant number (2019)44)]; Nature Science Foundation of Guizhou Provincial Science and Technology Department: [Grant Number (No. (2020) 1Y202)].