Mathematical Modeling of Single Peak Dynamic Recrystallization Flow Stress Curves in Metallic Alloys

Abstract

Deformation of metals and alloys at temperatures above 0.5 Tm is a complex process in which mechanical working interacts with various metallurgical processes such as dynamic restoration including recovery and recrystallization, and phase transformation for polymorphous materials. The understanding of these processes, however, enables the behavior of the metals and alloys. Recent developments have been described in several review papers. These reviews were in agreement that metals and alloys having relatively low values of stacking fault energy (SFE) could recrystallize dynamically, whereas those of high SFE including bcc metals and alloys which behave in a manner similar to fcc metals of high SFE recovered dynamically only during high temperature deformation. So that, according to microstructural evolutions, material response can principally be divided into two categories in hot deformation: dynamic recovery (DRV) type and dynamic recrystallization (DRX) type. The process of recrystallization of plastically deformed metals and alloys is of central importance in the processing of metallic alloys for two main reasons. The first is to soften and restore the ductility of material hardened by low temperature deformation that occurring below about 50% of the absolute melting temperature which leads to lower forces. The second is to control the microstructure and mechanical properties of the final product. The analysis of metal forming process such as hot rolling, forging and extrusion has been dependent on various parameters including constitutive relation which contributes to stress- strain curves at high temperatures, shape of workpiece and product, shapes of tools, friction, temperature, forming speed, etc. In such parameters, the constitutive equation is one of the most important factors which have an effect on solution accuracy. A