TiAl₃-TiN Composite Nanoparticles Produced by Hydrogen Plasma-Metal Reaction: Synthesis, Passivation, and Characterization.

Ju Li,Qing Mei

doi:10.3390/nano6060101

Abstract

TiAl3 and TiN composite nanoparticles were continuously synthesized from Ti–48Al master alloy by hydrogen plasma-metal reaction in a N2, H2 and Ar atmosphere. The phase, morphology, and size of the nanoparticles were studied by X-ray diffraction (XRD) and transmission electronic microscopy (TEM). X-ray photoelectron spectroscopy (XPS) and evolved gas analysis (EGA) were used to analyze the surface phase constitution and oxygen content of the nanoparticles. The as-synthesized nanopowders were mainly composed of nearly spherical TiAl3 and tetragonal TiN phases, with a mean diameter of ~42 nm and mass fractions of 49.1% and 24.3%, respectively. Passivation in the atmosphere of Ar and O2 for 24 h at room temperature led to the formation of amorphous Al2O3 shells on the TiAl3 particle surface, with a mean thickness of ~5.0 nm and a mass fraction of ~23.5%, as well as TiO2 with a mass fraction of ~3.2%.

Highlights

Hydrogen plasma-metal reaction (HPMR) is an effective method to synthesis nanoparticles of pure metals or alloys that was first developed by Uda and coauthors [1,2,3]
In our previous study [18], Al2O3/Ti2AlN composites with a novel combination of high temperature properties were fabricated successfully from TiAl3-TiN composite nanoparticles by HPMR, for which quantitative characterization of the composition, surface structure, and phase fraction of the composite nanoparticles after passivation is of great importance
We reported the synthesis and quantitative characterization of TiAl3-TiN composite nanoparticles from a Ti-Al binary system by hydrogen plasma-metal reaction in a N2, H2, and Ar atmosphere

Summary

Introduction

Hydrogen plasma-metal reaction (HPMR) is an effective method to synthesis nanoparticles of pure metals or alloys that was first developed by Uda and coauthors [1,2,3]. Nanoparticles of pure metals and different binary or ternary alloys have been successfully produced by HPMR [5,6,7,8,9]. In previous studies [11,12], nanoparticles of titanium aluminides were investigated in the Ti-Al binary alloy by HPMR. In our previous study [18], Al2O3/Ti2AlN composites with a novel combination of high temperature properties were fabricated successfully from TiAl3-TiN composite nanoparticles by HPMR, for which quantitative characterization of the composition, surface structure, and phase fraction of the composite nanoparticles after passivation is of great importance

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Results

Conclusion