Growth kinetics of ellipsoidal ω-precipitates in a Ti–20 wt%Mo alloy under compressive stress

Abstract

The influence of applied compressive stress on the growth kinetics of ellipsoidal ω phase precipitates was investigated for a Ti−20wt%Mo alloy aged at 300 °C. The application of compressive stress accelerated the growth of ω-precipitates when the misfit strain ε Μ of the precipitates along the loading direction is smaller than 0, whereas it did not essentially induce the same effect in cases where ε Μ > 0. The growth of the precipitates was interface-controlled in the case where ε Μ < 0 under a compressive stress of 450 − 550 MPa.The interface-controlled growth rate increased linearly with increasing the compressive stress.The interface-controlled growth rate under a compressive stress was slower than that under the same tensile stress in the case ε Μ > 0.

Generalizing Ellipsoidal Growth

“…In this situation, the ferrite grains may form elongated instead of equiaxed 2 . A less common example is the precipitation in a Ti-20wt%Mo alloy under compressive stress 3 that results in parallel ellipsoidal precipitates. Ellipsoids are the first approximation for elongated grains.…”