Tuning Microstructure and Mechanical Performance of a Co-Rich Transformation-Induced Plasticity High Entropy Alloy.

Area of Science:

• Materials Science
• Metallurgy
• Mechanical Engineering

Background:

• High-entropy alloys (HEAs) and multi-principal element alloys are advanced metallic materials with unique properties.
• Co-rich TRIP-HEAs offer high performance but require microstructural optimization.
• Thermomechanical processing (TMP) is a key technique for tailoring alloy characteristics.

Purpose of the Study:

• To investigate the impact of thermomechanical processing (TMP) on the microstructure of a Co-rich TRIP-high-entropy alloy (HEA).
• To correlate microstructural changes with room-temperature tensile performance.
• To provide insights for optimizing TMP strategies for TRIP-HEAs.

Main Methods:

• Characterization of HEA microstructures after various TMP routines.
• Room-temperature tensile testing to evaluate mechanical performance.
• Analysis of the relationship between microstructure and mechanical properties.

Main Results:

• Grain refinement via TMP effectively enhances both yield strength (254.6 to 641.3 MPa) and ultimate tensile strength (702.5 to 968.4 MPa).
• Satisfactory tensile elongation (68.8%) was maintained despite significant strength improvements.
• Formation of incoherent precipitates offered minor strength gains but reduced ductility.

Conclusions:

• Grain refinement is a crucial strategy for improving strength in TRIP-HEAs without compromising ductility.
• Careful consideration of precipitate formation is necessary during TMP optimization.
• This study provides valuable data for the microstructural and mechanical property regulation of TRIP-HEAs.