Mechanical properties of Co 3 Ti with simultaneous additions of tungsten and boron

Abstract

The mechanical properties of recrystallised Co₃Ti alloys with simultaneous additions of W (or Mo) and B were investigated by tensile and creep testing. The simultaneous additions of W (or Mo) and B enhanced significantly the yield strength of Co₃Ti alloys over the temperature range used. The stress exponent in the relationship ɛ∝σⁿ (where ɛ is creep rate and σ is stress) was 2·9 at 1073 K and the activation energy for creep deformation was 286 kJ mol⁻¹ at 147 MN m⁻² in unalloyed Co₃Ti. The simultaneous addition of W and B to Co₃Ti also enhanced the creep resistance. As with unalloyed Co₃Ti, addition of Fe to Co₃Ti alloys with simultaneous additions of W and B was effective in suppressing environmental embrittlement. The role of simultaneous additions of these elements was discussed, based on the results obtained.

MST/1594