Phase Studies of Additively Manufactured Near Beta Titanium Alloy-Ti55511

Area of Science:

• Materials Science
• Additive Manufacturing
• Metallurgy

Background:

• Additive manufacturing (AM) enables complex metal part fabrication.
• Titanium alloys, like Ti55511, are crucial for aerospace and medical applications.
• Comparing EBM and SLM for Ti55511 processing is vital for material selection.

Purpose of the Study:

• To compare electron-beam melting (EBM) and selective laser melting (SLM) effects on Ti55511.
• To evaluate chemical, phase, density, microstructure, and microhardness changes.
• To analyze powder characteristics post-processing for both EBM and SLM.

Main Methods:

• Processing of Ti55511 alloy using EBM and SLM.
• Characterization of as-built blocks for chemical and phase composition.
• Microstructural analysis and microhardness testing.
• Evaluation of powder morphology and characteristics after processing.

Main Results:

• Both EBM and SLM achieved high density (>99%) Ti55511 parts without defects.
• SLM retained the initial phase composition; EBM induced significant phase changes (α Ti-phase).
• EBM samples exhibited lamellar microstructures and higher microhardness (348 ± 30.20 HV) compared to SLM.
• Powder morphology showed similar variations for both EBM and SLM.

Conclusions:

• EBM and SLM are viable for Ti55511 additive manufacturing.
• Process choice significantly impacts phase composition and microstructure.
• EBM processing leads to increased microhardness in Ti55511 compared to SLM.