Microstructure Evolution of Ni₃Al-Based Intermetallic Alloy Strips After Hot Rolling.

Area of Science:

• Materials Science
• Metallurgy
• Physical Chemistry

Background:

• Nickel-aluminum (Ni3Al) intermetallic alloys are crucial for high-temperature applications.
• Controlling microstructure during processing is key to optimizing alloy performance.
• Hot rolling is a primary method for shaping and refining these alloys.

Purpose of the Study:

• To investigate the influence of hot rolling temperature and strain rate on the microstructural evolution of fine-grained Ni3Al alloys.
• To understand the mechanisms governing grain refinement during hot rolling.
• To develop a heat transfer model for analyzing thermal effects during processing.

Main Methods:

• Hot rolling experiments were conducted on Zr and B doped Ni3Al alloys.
• Temperatures ranged from 1000 to 1280 °C, with strain rates from 0.39 to 2.5 s⁻¹.
• Electron Backscatter Diffraction (EBSD) was used for microstructural analysis.
• A non-stationary heat transfer model was formulated and applied.

Main Results:

• Dynamic recrystallization was observed to initiate at 1100 °C.
• The volume fraction of dynamically recrystallized grains increased with both temperature and strain rate.
• The heat transfer model provided insights into experimental thermal conditions.

Conclusions:

• Hot rolling parameters critically control dynamic recrystallization in Ni3Al alloys.
• Optimizing temperature and strain rate can enhance microstructural refinement.
• The study provides a foundation for advanced processing of Ni3Al alloys.