Flow behavior and processing map for hot deformation of W-1.5ZrO2 alloy

Abstract

Compression tests of W-1.5ZrO2 alloy were carried out on a Gleeble-1500D thermal simulator at temperatures ranging from 1000 °C to 1400 °C and strain rates ranging from 0.01 to 1 s−1. The flow stresses, microstructure evolution and processing parameters optimization in different deformation conditions were investigated. The relationship between flow stress, strain rate and deformation temperature were also established based on the Arrhenius model. Furthermore, the law of activation energy and material constants with the variation of true strain was obtained in consideration of the strain influence. During hot deformation, the main restoration mechanism for W-1.5ZrO2 alloy was dynamic recrystallization (DRX) and dynamic recovery (DRV). DRV plays a dominant role in the high-temperature deformation of the W-1.5ZrO2 alloy. Partial DRX occurs in tungsten alloy when the temperature rises to 1400 °C, at the same time high temperature and low strain rate leads to the original grain growth. The obtained processing map of dynamic material modeling is used to analyze the deformation mechanism and the instability mechanism of the W-1.5ZrO2 alloy. For the strain of 0.5–0.6, the optimal processing parameters for the W-1.5ZrO2 alloy were in the temperature range of 1300 °C–1400 °C and strain rate range of 0.1–1 s−1.