scholarly journals Die Compaction of Low Oxygen Titanium Powder Produced by Gas Atomization.

1993 ◽  
Vol 40 (4) ◽  
pp. 405-409
Author(s):  
Masatomo Kamada ◽  
Setsuo Takaki ◽  
Youichi Tokunaga ◽  
Yasuyuki Ikeda ◽  
Hiroaki Shiraishi
Keyword(s):  
Titanium Powder ◽  
Gas Atomization ◽  
Low Oxygen ◽  
Die Compaction

Aiming at low-oxygen titanium powder: A review

2021 ◽  
Author(s):  
Kumar Debajyoti Jena ◽  
Sherry Xu ◽  
Muhammad D. Hayat ◽  
Wen Zhang ◽  
Peng Cao
Keyword(s):  
Titanium Powder ◽  
Low Oxygen

scholarly journals Effective Method for Preparing Low-Oxygen Titanium Ingot by Combined Powder Deoxidation and Vacuum Arc Melting Processes

2021 ◽  
Vol 59 (3) ◽  
pp. 149-154
Author(s):  
Jung-Min Oh ◽  
Jaeyeol Yang ◽  
Jaesik Yoon ◽  
Jae-Won Lim
Keyword(s):  
Oxygen Concentration ◽  
Titanium Powder ◽  
Semiconductor Industry ◽  
High Vacuum ◽  
Vacuum Arc ◽  
Low Oxygen ◽  
Arc Melting ◽  
Vacuum Arc Melting ◽  
Low Concentrations ◽  
Calcium Vapor

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.

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

2016 ◽  
Vol 704 ◽  
pp. 68-74 ◽  
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.

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

2020 ◽  
Vol 31 (9) ◽  
pp. 3774-3780
Author(s):  
Gye-Hoon Cho ◽  
Taeheon Kim ◽  
Jikwang Chae ◽  
Jae-Won Lim
Keyword(s):  
Titanium Hydride ◽  
Titanium Powder ◽  
Low Oxygen

New Chances for the Masteralloy Approach

2018 ◽  
Vol 18 (2) ◽  
pp. 121-127
Author(s):  
Raquel de Oro Calderon ◽  
Maryam Jaliliziyaeian ◽  
John Dunkley ◽  
Christian Gierl-Mayer ◽  
Herbert Danninger
Keyword(s):  
Low Cost ◽  
Alloying Elements ◽  
Particle Sizes ◽  
Gas Atomization ◽  
Low Oxygen ◽  
Ultra High Pressure ◽  
Sintered Steels ◽  
Water Atomization ◽  
Pressure Water ◽  
Impact Energies

Abstract The Masteralloy (MA) alloying route has a great potential for reducing the alloying costs in sintered steels, while allowing the introduction of innovative alloying systems. However, in order to achieve an efficient use of the alloying elements, the particle sizes needed are often below 25 µm, which means that for standard gas atomization a significant fraction of the batch has to be discarded or at least recycled. This work evaluates the performance of steels containing MA powders obtained with a novel atomization technique (Ultra-High-Pressure Water atomization) that allows the production of low-cost powders with low oxygen contents, rounded morphologies and mean particle sizes as low as 6 microns. Mechanical properties, dimensional variations and interstitial contents were measured in steels containing different MA compositions sintered at either 1120 °C or1250 ºC in N2-5H2 atmospheres. Already with less than 3 wt.% of alloying elements these steels present excellent combinations of properties, reaching strength levels of 560-915 MPa and hardness 220-260 HV10, combined with elongations of 1.3-3.2% and impact energies around 20-30 J/cm2.

A TEM study of the effect of oxygen on nanocavity formation and precipitation in rapid - solidified Fe-16Ni-9Cr stainless steels

1994 ◽  
Vol 52 ◽  
pp. 700-701
Author(s):  
S. Wisutmethangoon ◽  
T. F. Kelly ◽  
J.E. Flinn
Keyword(s):  
Stainless Steels ◽  
High Mobility ◽  
Hot Extrusion ◽  
Extrusion Ratio ◽  
Gas Atomization ◽  
Cavity Formation ◽  
Nucleation Sites ◽  
Heat Treated ◽  
Different Types ◽  
Effect Of Oxygen

Vacancies are introduced into the crystal phase during quenching of rapid solidified materials. Cavity formation occurs because of the coalescence of the vacancies into a cluster. However, because of the high mobility of vacancies at high temperature, most of them will diffuse back into the liquid phase, and some will be lost to defects such as dislocations. Oxygen is known to stabilize cavities by decreasing the surface energy through a chemisorption process. These stabilized cavities, furthermore, act as effective nucleation sites for precipitates to form during aging. Four different types of powders with different oxygen contents were prepared by gas atomization processing. The atomized powders were then consolidated by hot extrusion at 900 °C with an extrusion ratio 10,5:1. After consolidation, specimens were heat treated at 1000 °C for 1 hr followed by water quenching. Finally, the specimens were aged at 600 °C for about 800 hrs. TEM samples were prepared from the gripends of tensile specimens of both unaged and aged alloys.

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

2013 ◽  
Vol 83 (3) ◽  
pp. 188-197 ◽  
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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