Investigation of Microstructure, Mechanical, and Tribological Behavior of Nano‐Y2O3, TiO2, ZrO2‐Dispersed W–Ni–Nb–Mo–Zr Alloys Fabricated by Spark Plasma Sintering

Abstract

W–Ni–Nb–Mo–Zr alloys with 1.0 weight% (wt%) Y2O3 (alloy A), TiO2 (alloy B), ZrO2 (alloy C) dispersion synthesized by mechanical alloying for 20 h have been subjected to spark plasma sintering at 1150 °C with 65 MPa pressure and 5 min holding time. X‐ray diffraction analysis reveals the occurrence of intermetallics (W2Zr, NiNb, Ni10Zr7, MoNi), which improves the strength of the alloys. Field‐emission scanning electron microscopy analysis shows that the grain size of alloy A is less compared to alloy B and C. Energy‐dispersive spectroscopy reveals the presence of oxides at the matrix interface. Maximum % relative sintered density, ultrahigh hardness, excellent compressive strength, % compressive strain at the maximum compressive load of 99.5%, 20.42 GPa of 2.55 GPa, 9.7%, respectively, have been recorded for alloy A. Maximum texture intensity of 1.5 is recorded for alloy A which supports the superior mechanical properties. The specific wear rate of alloy A is around 2.78 times less compared to alloy C. The crystal structure transformation of ZrO2 from monoclinic to tetragonal after sintering deteriorates the mechanical properties and wear resistance in alloy C. The article also reports the operative wear mechanism in the studied oxide dispersion‐strengthened alloy.