Single crystal growth of TIMETAL LCB titanium alloy by a floating zone method

TL;DR

This paper presents a method for growing single crystals of TIMETAL LCB titanium alloy using an optical floating zone furnace, analyzing composition stability and microstructure during the process.

Contribution

It introduces a novel single crystal growth technique for TIMETAL LCB alloy and investigates compositional and microstructural changes during growth.

Findings

Base alloying element concentrations remain stable during growth.

Interstitial elements O and N increase during the process.

Single crystal exhibits a mosaic structure with 60 nm mosaic blocks.

Abstract

The methodology of single crystal growth of metastable $\beta$-Ti alloy TIMETAL LCB in an optical floating zone furnace is presented in this paper. Chemical compositions of both precursor material and single crystals were checked. It was found that the concentration of base alloying elements did not change significantly during the growth process, while the concentrations of interstitial elements O and N increased. DSC measurement determined that this concentration shift has a slight impact on ongoing phase transformations, as in the single-crystalline material peak associated with $\alpha$ phase precipitation moves by a few degrees to a lower temperature and peak attributed to diffusion controlled growth of $\omega$ particles shifts to a higher temperature. X-ray reciprocal space maps were measured and their simulation showed that the single crystal has a mosaic structure with mean size of mosaic blocks of approximately 60 nm.