Compression Behavior and Textures of Ti57-Nb43 Alloy at High Temperatures

Area of Science:

• Materials Science
• Metallurgical Engineering
• Mechanical Engineering

Background:

• Understanding the hot deformation behavior of titanium-niobium (Ti-Nb) alloys is crucial for optimizing manufacturing processes.
• Previous studies have explored Ti-Nb alloys, but detailed investigations into their mechanical behavior, microstructure, and crystallographic textures under various hot deformation conditions are still needed.

Purpose of the Study:

• To investigate the mechanical behavior, microstructures, and crystallographic textures of Ti57-Nb43 alloy during hot compression.
• To develop a predictive model for flow stress based on temperature and strain rate.
• To analyze the influence of dynamic recrystallization/recovery on deformation textures.

Main Methods:

• Compression testing of cylindrical Ti57-Nb43 alloy specimens at temperatures from 700-1000 °C and strain rates from 0.001-1.0 s⁻¹.
• Analysis of stress-strain curves using a modified Voce-type equation and a novel two-variable polynomial function.
• Characterization of crystallographic textures using X-ray diffraction and viscoplastic polycrystal self-consistent (VPSC) modeling.

Main Results:

• Observed hardening followed by softening behavior due to dynamic recrystallization/recovery.
• A four-parameter model accurately described the flow curves, with a new polynomial function predicting flow stress across the investigated range.
• Crystallographic textures showed a double <100> and <111> fiber and a (001) <110> component, with VPSC modeling confirming dynamic recrystallization's effect on texture intensity but not development.

Conclusions:

• The developed model provides a predictive tool for Ti57-Nb43 alloy's flow stress under hot deformation conditions.
• Dynamic recrystallization and recovery significantly influence the mechanical response and texture evolution.
• The findings contribute to a better understanding of Ti-Nb alloy processing and performance.