Oxidation behaviors of Nb-15W and Nb-15W-10Cr alloys fabricated by vacuum hot-pressing sintering

Vacuum hot-pressing sintering (VHPS) was used for fabricating Nb-15W and Nb-15W-10Cr (at.%) alloys under 30 MPa for 60 min at 1800 °C in pure argon atmosphere. Microstructure and oxidation resistance of both materials were investigated. Microstructure analysis showed that the as-sintered Nb-15W alloy only consisted of α-Nb (W) solid solution and the as-sintered Nb-15W-10Cr alloy composed of α-Nb (W, Cr) solid solution and small amount cubic type NbCr2 Laves phase due to addition of 10 at.% Cr. The oxidation at 1300 °C for 4 h exhibited that the addition of 10 at.% Cr increased the oxidation rate of Nb-15W alloy. The effects of Cr on the oxidation behaviors are discussed in detail.

► Vacuum hot-pressing sintering (VHPS) was used for preparing Nb-15W and Nb-15W-10Cr alloys under 30 MPa for 60 min at 1800 °C.
► Oxidation behaviors of Nb-15W alloy fabricated by VHPS at 1300 °C were studied.
► The addition of lower Cr content increased the oxidation rate of Nb–W system.