Factors affecting dynamic recrystallization of metals and alloys

Abstract

The high-temperature mechanical behaviour of copper, Cu-Al alloys, and nickel has been examined using torsional testing with hollow testpieces in conjunction with microstructural observations on deformed and quenched specimens using both optical and electron microscopy. Dynamic recrystallization occurred in these materials as the restoration process during high-temperature deformation. The factors influencing dynamic recrystallization have been considered, including materials of high stacking fault energy. It was found that the regime of dynamic recrystallization and the transition in flow stress behaviour could be reasonably represented in terms of the Zener-Hollomon parameter. In Cu-Al solid solution alloys, although the addition of the solute aluminium into copper lowered the stacking fault energy, dynamic recrystallization was retarded to higher strains due to the reduced mobility of the grain boundary. By mechanical and microstructural analysis of the behaviour of various single phase metals and alloys during dynamic recrystallization, the factors influencing the behaviour (i.e. stacking fault energy (solute elements), Zener-Hollomon parameter (deformation condition), and strain) can be summarized on a three dimensional schematic.MST/587

Processing parameters for the mechanical working of 9 Cr–1 Mo steel: processing maps approach

“…The DRX domains are greatly influenced by alloying elements as well as by various phases present in the material. 14 At the test temperatures used, the phase is austenite and the high temperature domain of this material matches with other austenitic stainless steels. 15 The DRX mechanism may be discussed on the basis of a simple DRX model, which considers the rate of nucleation versus the rate of grain boundary migration.…”

Critical Strain for Dynamic Recrystallisation. The Particular Case of Steels

“…Additionally, the work published by Ueki et al [38] was conducted in order to clarify the behavior of DRX in non-ferrous metals and alloys on the basis of the results obtained from mechanical tests and microstructural observations. The investigators critically discussed the factors that influence the occurrence of DRX and proposed a new way of classifying the operative dynamic restoration processes.…”

Determination of flow stress and the critical strain for the onset of dynamic recrystallization using a hyperbolic tangent function

“…A driving force of dislocation removal initiates dynamic recrystallization, and let the flow stress increases with a declining rate, up to a maximum value (the peak), which indicates the rate of softening mechanism prevails over the work hardening. This phenomenon usually occurs for metals with low to medium stacking fault energy [6]. The influence of DRX would be more obvious as temperature rises or strain rate lowers [7].…”