Preparing low-oxygen titanium powder by calcium reductant from titanium hydride

In this study, an effective method is demonstrated for fabricating titanium sputtering targets, which are used to fabricate thin films in the semiconductor industry. The method is an alternative to the existing electron beam melting (EBM) process under high vacuum. Titanium sputtering targets used in the production of semiconductors must have very low concentrations of gaseous impurities, especially oxygen, as well as metal impurities. Currently, the oxygen concentration in titanium sputtering targets used for industrial purposes is less than 400 ppm. To develop an effective alternative method, powder metallurgy and melting processes were performed to prepare a low-oxygen titanium ingot with less than 400 ppm oxygen. First, titanium powder was deoxidized using calcium vapor, and then the powder was subjected to vacuum arc melting (VAM). The oxygen in the titanium powder was reduced with calcium vapor from an initial concentration of 2200 ppm to 800 ppm, and the resulting powder was melted using VAM, resulting in titanium ingots with low oxygen content, 400 ppm or less. It was also confirmed that all lattice constants, i.e., <i>d, a, c,</i> and <i>c/a</i>, decreased as oxygen concentration decreased in both the titanium powder and the ingots.

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Powder Consolidation of Titanium and Titanium Alloys by a Powder Compact Forging Process

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.704.68 ◽

2016 ◽

Vol 704 ◽

pp. 68-74 ◽

Cited By ~ 3

Author(s):

Ming Tu Jia ◽

Brian Gabbitas

Keyword(s):

Mechanical Properties ◽

Powder Compact ◽

Titanium Powder ◽

Full Density ◽

Low Oxygen ◽

Powder Consolidation ◽

Forging Process ◽

Cp Ti ◽

Field Assisted Sintering ◽

Powder Compacts

Powder compact forging in combination with induction sintering, a field assisted sintering technique (FAST), was used to produce commercially pure (CP) Ti and Ti-13V-11Cr-3Al parts. Green powder compacts with high relative density were manufactured by cold compaction and warm compaction, respectively. During the powder compact forging process, CP titanium powder was consolidated completely to produce a near net shaped top cover for a diving helmet with full density and good mechanical properties. Also, a Ti-13V-11Cr-3Al alloy was fully consolidated into a cylinder using blended elemental powders. As a comparison, raw titanium powder with different oxygen contents was used to make a Ti-13V-11Cr-3Al powder compact forging. Using a starting powder with low oxygen content, a forged cylinder with good mechanical properties was produced.

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Quantitative Evaluation of Interstitial Elements in the Processing of Ti-6Al-4V Alloy by Powder Metallurgy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.727-728.374 ◽

2012 ◽

Vol 727-728 ◽

pp. 374-379 ◽

Cited By ~ 1

Author(s):

S.L.G. Petroni ◽

V.A.R. Henriques ◽

M.S.M. Paula ◽

C.A.A. Cairo

Keyword(s):

Powder Metallurgy ◽

Titanium Hydride ◽

Titanium Powder ◽

Milling Time ◽

Sintering Temperature ◽

Low Cost ◽

High Reactivity ◽

Holding Time ◽

Carbon Absorption ◽

Interstitial Elements

The use of hydride powders in titanium powder metallurgy (P/M) is a low cost alternative for the manufacture of titanium alloys. However, due to the high reactivity of these powders, parts produced using this technique may contain interstitial impurities such as oxygen, nitrogen and carbon. In this work a factorial design approach was used to evaluate the influence of some stages of P/M upon the levels of these elements in sintered samples of Ti-6Al-4V. Milling time of titanium hydride powders, sintering temperature and holding time were evaluated. The effect of milling time was detected as the most significant for the increase in oxygen levels. The contents of all elements were affected by the increase of sintering temperature from 1200 °C to 1400 °C. Holding time was shown to be significant only for the carbon absorption in the samples sintered at 1400 °C.

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Thermodynamic Investigation of Titanium Hydride Formation from Reduction of Titanium (Ⅳ) Chloride with Magnesium Hydride in Presence of Hydrogen Atmosphere

MATEC Web of Conferences ◽

10.1051/matecconf/202032107014 ◽

2020 ◽

Vol 321 ◽

pp. 07014

Author(s):

Mohammad Rezaei Ardani ◽

Ahmad Fauzi Mohd Noor ◽

Sheikh Abdul Rezan Sheikh Abdul Hamid ◽

Abdul Rahman Mohamed ◽

Hooi Ling Lee ◽

...

Keyword(s):

Reaction Time ◽

Low Temperature ◽

Titanium Hydride ◽

Titanium Powder ◽

Milling Time ◽

Reduction Process ◽

Hydrogen Atmosphere ◽

Major Product ◽

X Ray ◽

Ball Milling Time

Thermodynamic assessment and experimental investigation for formation of titanium hydride (TiH2) from reduction of titanium tetrachloride (TiCl4) with magnesium hydride (MgH2) were carried out under hydrogen atmosphere. In this method, TiH2 production at low temperature was investigated, which can be used for further dehydrogenation process in titanium powder metallurgy. The effects of temperature, time, amount of titanium trifluoride (TiF3) as catalyst, and ball milling time of MgH2 on reduction process were evaluated. The range of each parameters were set to 250-350°C for temperature, 2-4 hr for reaction time, 4-10 wt% for TiF3, and 1-2 hr for ball milling time. The phase transformations after reduction process were studied by X-ray diffraction (XRD) and energy-dispersive X-ray (EDX) analyziz. The morphology of powders was analyzed by scanning electron microscope (SEM). The results showed that titanium trichloride (TiCl3) was formed as major product in experiments for the above conditions. However, with increasing the reaction time above 10hr, characterization study of the final products confirmed the formation of TiH2 as major product. Our findings indicated that producing of TiH2 from reduction of TiCl4 with MgH2 at low temperature was feasible and could lead to low cost synthesis method for TiH2 for titanium powder production.

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Carpenter launches first high-strength, low-oxygen titanium powder

Metal Powder Report ◽

10.1016/j.mprp.2017.08.055 ◽

2017 ◽

Vol 72 (5) ◽

pp. 374

Keyword(s):

Titanium Powder ◽

High Strength ◽

Low Oxygen

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HIF1-α-Mediated Gene Expression Induced by Vitamin B1 Deficiency

International Journal for Vitamin and Nutrition Research ◽

10.1024/0300-9831/a000159 ◽

2013 ◽

Vol 83 (3) ◽

pp. 188-197 ◽

Cited By ~ 21

Author(s):

Rebecca L. Sweet ◽

Jason A. Zastre

Keyword(s):

Gene Expression ◽

Thiamine Deficiency ◽

Glucose Transporter ◽

Neuroblastoma Cell ◽

Hypoxia Inducible Factor ◽

Clinical Manifestations ◽

Vitamin B1 ◽

Low Oxygen ◽

Glucose Transporter 1 ◽

Metabolic Intermediates

It is well established that thiamine deficiency results in an excess of metabolic intermediates such as lactate and pyruvate, which is likely due to insufficient levels of cofactor for the function of thiamine-dependent enzymes. When in excess, both pyruvate and lactate can increase the stabilization of the hypoxia-inducible factor 1-alpha (HIF-1α) transcription factor, resulting in the trans-activation of HIF-1α regulated genes independent of low oxygen, termed pseudo-hypoxia. Therefore, the resulting dysfunction in cellular metabolism and accumulation of pyruvate and lactate during thiamine deficiency may facilitate a pseudo-hypoxic state. In order to investigate the possibility of a transcriptional relationship between hypoxia and thiamine deficiency, we measured alterations in metabolic intermediates, HIF-1α stabilization, and gene expression. We found an increase in intracellular pyruvate and extracellular lactate levels after thiamine deficiency exposure to the neuroblastoma cell line SK-N-BE. Similar to cells exposed to hypoxia, there was a corresponding increase in HIF-1α stabilization and activation of target gene expression during thiamine deficiency, including glucose transporter-1 (GLUT1), vascular endothelial growth factor (VEGF), and aldolase A. Both hypoxia and thiamine deficiency exposure resulted in an increase in the expression of the thiamine transporter SLC19A3. These results indicate thiamine deficiency induces HIF-1α-mediated gene expression similar to that observed in hypoxic stress, and may provide evidence for a central transcriptional response associated with the clinical manifestations of thiamine deficiency.

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