The TiRO™ Process for the Continuous Direct Production of Titanium Powder

The CSIRO is developing the TIRO™ process for the continuous direct production of titanium powder. The process comprises two stages. The first stage is a fluidised bed reactor (FBR) in which TiCl4 is reacted with magnesium powder to form solid magnesium chloride particles about 350 µm in diameter in which micron sized titanium particles are dispersed. The second stage is a continuous vacuum distillation operation where the titanium is separated from the magnesium chloride and sintered to form a friable “biscuit”. The biscuit comprises porous titanium spheres about 250 µm in diameter which can be liberated by very light grinding. The overall process has a throughput of 0.2 kg/h Ti, limited by the vacuum distillation unit and is being scaled up. The process has generated Ti powder with ≤0.25 wt% O and < 200 ppm Cl and meets CP2 specifications. Ring grinding the vacuum distilled product for short periods reduced the particle size, however longer grinding times caused agglomeration of the particles. Ring grinding in air resulted in a large increase in oxygen concentration

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Titanium Powder from the TiRO™ Process

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.520.95 ◽

2012 ◽

Vol 520 ◽

pp. 95-100 ◽

Cited By ~ 18

Author(s):

Christian Doblin ◽

Andrew Chryss ◽

Andreas Monch

Keyword(s):

Particle Size ◽

Magnesium Chloride ◽

Vacuum Distillation ◽

Titanium Powder ◽

Continuous Process ◽

Average Particle Size ◽

Average Particle ◽

Fluidised Bed ◽

Direct Production ◽

Tap Density

A new continuous process for the direct production of CP titanium powder is being developed at CSIRO. The TiRO™ process has two major steps. The first step is conducted in a fluidised bed where titanium tetrachloride and magnesium powder react to form small (1.5 µm) titanium metal particles uniformly dispersed inside larger spheroidal magnesium chloride particles with an average particle size of 350 µm. The second step involves vacuum distillation in which the magnesium chloride is removed from the titanium. During vacuum distillation the magnesium chloride is volatilised and the micron sized titanium particles come together to form partially sintered predominantly spheroidal porous particles with a similar shape to the starting particle, some which appeared to be hollow. A mechanism for their formation is proposed. The spheroidal particles are all lightly sintered together. The vacuum distilled product was very lightly ground to liberate the spheroidal particles which had an average particle size of about 200 µm. With further grinding an angular Ti powder was produced. The ground titanium was free flowing and had a tap density of 2.4 g/cm3.

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Preparation and Properties of Titanium Obtained by Spark Plasma Sintering of a Ti Powder–Fiber Mixture

Materials ◽

10.3390/ma11122510 ◽

2018 ◽

Vol 11 (12) ◽

pp. 2510 ◽

Cited By ~ 3

Author(s):

Mingjun Shi ◽

Shifeng Liu ◽

Qingge Wang ◽

Xin Yang ◽

Guangxi Zhang

Keyword(s):

Spark Plasma Sintering ◽

Titanium Powder ◽

Raw Materials ◽

Strain Curve ◽

Porous Titanium ◽

Plasma Sintering ◽

Mass Transfer Mechanism ◽

Material Migration ◽

Spark Plasma ◽

Ti Powder

Porous titanium is a functional structural material with certain porosity, which is prepared from titanium powder and titanium fiber. In order to study the porosity, phase structure, microstructure, sintering mechanism and mechanical properties of porous titanium obtained by spark plasma sintering of a Ti powder–fiber mixture at different sintering temperatures, a spherical titanium powder (D50 of 160 μm) was prepared via plasma rotating electrode processing, and titanium fiber (average wire diameter of fiber of 110 μm) was prepared by drawing, and they were mixed as raw materials according to different mass ratios. Porous titanium with a fiber–powder composite porous structure was prepared by spark plasma sintering at sintering temperatures of 800 °C, 900 °C and 1000 °C under a sintering pressure of 20 MPa. The results showed that there were no new phases occurring in porous titanium with porosity of 1.24–24.6% after sintering. Titanium fiber and titanium powder were sintered using powder/powder, powder/fiber and fiber/fiber regimes to form composite pore structures. The mass transfer mechanism of the sintered neck was a diffusion-dominated material migration mechanism during sintering. At higher sintering temperatures, the grain size was larger, and the fiber (800 °C; 10–20 μm) was finer than the powder (800 °C; 10–92 μm). The stress–strain curve of porous titanium showed no obvious yield point, and the compressive strength was higher at higher sintering temperatures. The results of this paper can provide data reference for the preparation of porous titanium obtained by spark plasma sintering of a Ti powder–fiber mixture.

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Processing TiROTM Powder for Strip Production and other Powder Consolidation Applications

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.704.293 ◽

2016 ◽

Vol 704 ◽

pp. 293-301 ◽

Cited By ~ 1

Author(s):

Christian Doblin ◽

G.M. Delphine Cantin ◽

Stefan Gulizia

Keyword(s):

Fine Particles ◽

Small Sample ◽

Gas Atomization ◽

Direct Production ◽

Powder Consolidation ◽

Manufacturing Applications ◽

Ti Powder ◽

Continuous Vacuum ◽

Individual Particles ◽

Strip Production

The TiROTM process has been developed at CSIRO for the continuous direct production of Ti powder. The process has two main steps; a reaction step where the Ti is produced as very fine particles dispersed in larger particles of magnesium chloride. The MgCl2 is separated from the Ti powder in a continuous vacuum distillation unit. The Ti product from this unit comprises a lightly sintered “biscuit” of Ti particles that can be broken up into individual particles powder with a d50 around 200 μm. These particles have a unique morphology which is a function of the process.For many powder metallurgical applications TiROTM powder will require further processing to tailor its morphology for the specific application. A small sample of Ti strip has been produced from ring milled TiROTM powder by a CSIRO patented combination of direct powder rolling (DPR) followed by hot roll densification (HRD). The Ti strip was annealed and characterised in terms of microstructure and chemistry.A powder manipulation technology (PMT) has been developed to modify TIROTM particulates without the need of more expensive hydride-dehydride (HDH) or gas atomization routes to improve density, flowability, size, distribution and shape for cold spray and additive manufacturing applications.

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