Consolidation of Titanium Powder by Electrical Resistance Sintering: Practice and Simulation

2021 ◽  
Vol 876 ◽  
pp. 1-6
Author(s):  
Fátima Ternero Fernández ◽  
Petr Urban ◽  
Raquel Astacio Lopez ◽  
Rosa M. Aranda Louvier ◽  
Francisco G. Cuevas
Keyword(s):  
Electrical Resistance ◽  
Titanium Powder ◽  
Low Voltage ◽  
Pure Titanium ◽  
Commercially Pure Titanium ◽  
Consolidation Process ◽  
Simultaneous Application ◽  
Microhardness Distribution ◽  
Powder Mass ◽  
Furnace Sintering

In this work, a commercially pure titanium powder has been consolidated using the Electrical Resistance Sintering (ERS) process. This technique consists in the consolidation of a powder mass by the simultaneous application of pressure (80 MPa, in this work) and heating caused by the passage of a high intensity (3.5-6.0 kA, in this case) and low voltage current (lower than 10 V), during short dwelling times (0.8-1.6 s, in this work). The resulting compacts have been mechanically characterised by measuring their microhardness distribution. The results obtained are compared with the corresponding values of compacts prepared with the same powders following the conventional P/M route of cold pressing and furnace sintering. The results of some simulations are provided to give information about the temperatures reached inside the compacts during the electrical consolidation process.

scholarly journals Nickel Porous Compacts Obtained by Medium-Frequency Electrical Resistance Sintering

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2131
Author(s):  
Fátima Ternero ◽  
Eduardo S. Caballero ◽  
Raquel Astacio ◽  
Jesús Cintas ◽  
Juan M. Montes
Keyword(s):  
Electrical Resistance ◽  
Nickel Powder ◽  
Low Voltage ◽  
Applied Pressure ◽  
Electrical Current ◽  
Heating Time ◽  
Medium Frequency ◽  
Microhardness Distribution ◽  
Furnace Sintering ◽  
Porous Compacts

A commercially pure (c.p.) nickel powder was consolidated by Medium-Frequency Electrical Resistance Sintering (MF-ERS). In this consolidation technique, a pressure and the heat released by a high-intensity and low-voltage electrical current are concurrently applied to a metal powder mass. A nickel powder with a high tap porosity (86%) and a low applied pressure (only 100 MPa) is chosen in order to be able to obtain compacts with different levels of porosity, to facilitate the study of the porosity influence on the compact properties. The influence of current intensity and heating time on the global porosity values, the porosity and microhardness distribution, and the electrical conductivity of the sintered compacts is studied. The properties of the compacts consolidated by MF-ERS are compared with the results obtained by the conventional powder metallurgy route, consisting of cold pressing and furnace sintering. A universal equation to describe the porosity influence on all the analyzed properties of powder aggregates and sintered compacts is proposed and validated.

scholarly journals Medium-Frequency Electrical Resistance Sintering of Soft Magnetic Powder Metallurgy Iron Parts

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 994
Author(s):  
Raquel Astacio ◽  
Fátima Ternero ◽  
Jesús Cintas ◽  
Francisco G. Cuevas ◽  
Juan Manuel Montes
Keyword(s):  
Powder Metallurgy ◽  
Electrical Resistance ◽  
Low Voltage ◽  
Vacuum Furnace ◽  
Soft Magnetic ◽  
Medium Frequency ◽  
Joule Effect ◽  
Simultaneous Application ◽  
Cold Pressing ◽  
Furnace Sintering

The fabrication of soft magnetic Fe parts by the medium-frequency electrical resistance sintering (MF-ERS) technique is studied in this paper. This consolidation technique involves the simultaneous application to metallic powders of pressure and heat, the latter coming from the Joule effect of a low-voltage and high-intensity electric current. Commercially pure iron powder was used in the consolidation experiences. The porosity distribution, microhardness, electrical resistivity and hysteresis curves of the final compacts were determined and analysed. The results obtained were compared both with those of compacts consolidated by the conventional powder metallurgy (PM) route of cold pressing and vacuum furnace sintering, and with fully dense compacts obtained by double cycle of cold pressing and furnace sintering in hydrogen atmosphere.

Study on selective laser melting of commercially pure titanium powder

2018 ◽  
Vol 233 (7) ◽  
pp. 1794-1807 ◽  
Author(s):  
Kurian Antony ◽  
T Reghunathan Rakeshnath
Keyword(s):  
Energy Density ◽  
Laser Power ◽  
Titanium Powder ◽  
Laser Energy ◽  
Pure Titanium ◽  
Commercially Pure Titanium ◽  
Laser Track ◽  
Laser Melting ◽  
Commercially Pure ◽  
Powder Particles

Laser additive manufacturing processes melt the powder particles using laser beam energy to form solid three-dimensional objects. This article mainly focuses on numerical analysis and experimentation of laser melting of commercially pure titanium powder. Numerical solutions to moving heat source problems were developed, and their influences on process parameters were validated. The energy density has a significant role in laser melting process. The numerical investigation demonstrates the significant effect of laser energy density on laser tracks. The laser power, distribution of powder particles, the absorptivity, density, and chemical constitution of powder materials are the main factors which influence the laser energy penetration. The absorptivity plays a vital role in consolidation phenomena of the powder layer which helps to get a denser part or layer. The experimental result clearly indicates that at lower laser speed the powder compaction is better. Temperature distribution, depth, and width of laser track were compared in this article. By investigating the observations from optical microscopic images and scanning electron microscopic images, the surface characteristics of laser-melted tracks were studied. The study on numerical and experimental results shows that the optimum condition for better laser track is laser power 45 W, laser speed 20 mm/s, and laser diameter 2.5 mm. This study provides important insights into laser parameters in the melting of commercially pure titanium powder.

Enhancement of Hard Disk Drive Performance by Using Thin Titanium Foil Disk Substrates

2013 ◽  
Author(s):  
Anil Nigam ◽  
James White
Keyword(s):  
Low Voltage ◽  
Pure Titanium ◽  
Form Factors ◽  
Hard Disk ◽  
Disk Drive ◽  
Titanium Foil ◽  
Commercially Pure Titanium ◽  
Battery Power ◽  
Commercially Pure ◽  
Titanium Substrates

In this paper an experimental study is reported to reduce the rotating inertia in a 2½″ HDD by replacing thick hard disk platters with thin, CP (commercially pure) titanium substrates in the range of 25 microns to 152 microns in thickness. The results of this work can be extended to other disk form factors [1]. The low inertia and thinness of the titanium foil platter can be exploited to allow disk drive products to be powered on/off rapidly, decreasing energy consumption. In addition, significantly faster rpms and data thru-put can be achieved. Also, many more disk platters can be housed in each unit, increasing storage capacity; while slimmer products that operate with low voltage battery power can be developed.

scholarly journals Tribological Characteristic of Titanium Alloy Surface Layers Produced by Diode Laser Gas Nitriding

2016 ◽  
Vol 61 (2) ◽  
pp. 543-552 ◽  
Author(s):  
A. Lisiecki ◽  
J. Piwnik
Keyword(s):  
Titanium Alloy ◽  
Diode Laser ◽  
Pure Titanium ◽  
Commercially Pure Titanium ◽  
Volume Loss ◽  
Surface Layers ◽  
Composite Surface ◽  
Microhardness Distribution ◽  
Gas Nitriding ◽  
Commercially Pure

AbstractIn order to improve the tribological properties of titanium alloy Ti6Al4V composite surface layers Ti/TiN were produced during laser surface gas nitriding by means of a novel high power direct diode laser with unique characteristics of the laser beam and a rectangular beam spot. Microstructure, surface topography and microhardness distribution across the surface layers were analyzed. Ball-on-disk tests were performed to evaluate and compare the wear and friction characteristics of surface layers nitrided at different process parameters, base metal of titanium alloy Ti6Al4V and also the commercially pure titanium. Results showed that under dry sliding condition the commercially pure titanium samples have the highest coefficient of friction about 0.45, compared to 0.36 of titanium alloy Ti6Al4V and 0.1-0.13 in a case of the laser gas nitrided surface layers. The volume loss of Ti6Al4V samples under such conditions is twice lower than in a case of pure titanium. On the other hand the composite surface layer characterized by the highest wear resistance showed almost 21 times lower volume loss during the ball-on-disk test, compared to Ti6Al4V samples.

scholarly journals Medium-frequency Electrical Resistance Sintering of Oxidized c.p. Iron Powder

2018 ◽  
Author(s):  
Juan Manuel Montes Martos ◽  
Francisco Gómez Cuevas ◽  
Fátima Ternero Fernández ◽  
Raquel Astacio López ◽  
Eduardo Sánchez Caballero ◽  
...  
Keyword(s):  
Electrical Resistance ◽  
Low Voltage ◽  
Electrical Current ◽  
Medium Frequency ◽  
Sintered Compact ◽  
Resistance Evolution ◽  
Degree Of Oxidation ◽  
Powder Mass ◽  
Conventional Sintering ◽  
High Degree

Commercially pure (c.p.) iron powders with a deliberate high degree of oxidation were consolidated by medium-frequency electrical resistance sintering (MF-ERS). This is a consolidation technique where pressure, and heat coming from a low-voltage and high-intensity electrical current, are simultaneously applied to a powder mass. In this work, the achieved densification rate is interpreted according to a qualitative microscopic model, based on the compacts global porosity and electrical resistance evolution. The effect of current intensity and sintering time on compacts was studied on the basis of micrographs revealing the porosity distribution inside the sintered compact. The microstructural characteristics of compacts consolidated by the traditional cold-press and furnace-sinter powder metallurgy route are compared with results of MF-ERS consolidation. The goodness of MF-ERS versus the problems of conventional sintering when working with oxidized powders is analyzed. The electrical consolidation allows to obtain higher densifications than the traditional route under non-reducing atmospheres.

Consolidation Process in Near Net Shape Manufacturing of Armstrong CP-Ti/Ti-6Al-4V Powders

2010 ◽  
Vol 436 ◽  
pp. 103-111 ◽  
Author(s):  
Yukinori Yamamoto ◽  
Jim O. Kiggans ◽  
Michael B. Clark ◽  
Stephen D. Nunn ◽  
Adrian S. Sabau ◽  
...  
Keyword(s):  
Time Pressure ◽  
Low Cost ◽  
Pure Titanium ◽  
Cold Isostatic Pressing ◽  
Theoretical Density ◽  
Commercially Pure Titanium ◽  
Consolidation Process ◽  
The Press ◽  
Near Net Shape ◽  
Cp Ti

This paper summarizes our recent efforts to develop the manufacturing technologies of consolidated net-shape components by using new low-cost commercially pure titanium (CP-Ti) and Ti-6Al-4V alloy powders made by the Armstrong process. Fabrication processes of net shape/ near net shape components, such as uniaxial die-pressing, cold isostatic pressing (CIP), sintering, roll compaction and stamping, have been evaluated. The press-and-sinter processing of the powders were systematically investigated in terms of theoretical density and microstructure as a function of time, pressure, and temperature. Up to 96.4% theoretical density has been achieved with the press-and-sinter technology. Tensile properties of the consolidated samples exhibit good ductility as well as equivalent yield/ultimate tensile strengths to those of fully consolidate materials, even with the presence of a certain amount of porosity. A consolidation model is also under development to interpret the powder deformation during processing. Net shape components made of the Armstrong powder can successfully be fabricated with clearer surface details by using press-and-sinter processing.

TIMETAL 50A

Alloy Digest ◽  
2001 ◽  
Vol 50 (9) ◽  
Keyword(s):  
Electrical Resistance ◽  
Chemical Process ◽  
Room Temperature ◽  
Pure Titanium ◽  
Heat Treating ◽  
Commercially Pure Titanium ◽  
Bend Strength ◽  
Temperature Performance ◽  
Commercially Pure ◽  
Complex Shapes

Abstract TIMETAL 50A is a commercially pure titanium alloy with a minimum tensile strength of 345 MPa (50 ksi). It is readily formed at room temperature, although complex shapes must be warm formed for satisfactory results. This material is weldable by both electrical resistance and fusion procedures, although the latter methods can be used only if the material is protected from atmospheric contamination. This grade is used in airframe and chemical process applications. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and bend strength. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: TI-120. Producer or source: Timet.

scholarly journals Sintering High Green Density Direct Powder Rolled Titanium Strips, in Argon Atmosphere

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 936
Author(s):  
Anthony Govender ◽  
Clinton Bemont ◽  
Silethelwe Chikosha
Keyword(s):  
Titanium Powder ◽  
High Vacuum ◽  
Pure Titanium ◽  
Batch Process ◽  
Commercially Pure Titanium ◽  
Green Density ◽  
Vacuum Sintering ◽  
Daily Production ◽  
Argon Gas ◽  
Air Contamination

Presently, the majority of titanium powder metallurgy components produced are sintered under high vacuum due to the associated benefits of the vacuum atmosphere. However, high-vacuum sintering is a batch process, which limits daily production. A higher daily part production is achievable via a continuous sintering process, which uses argon gas to shield the part from air contamination. To date, there has been limited work published on argon gas sintering of titanium in short durations. This study investigated the properties of thin high green density titanium strips, which were sintered at the temperatures of 1100 °C, 1200 °C and 1300 °C for a duration of 30 min, 60 min and 90 min in argon. The strips were produced by rolling of −45 µm near ASTM (American Society for Testing and Materials) grade 3 hydride–dehydride commercially pure titanium powder. The density, hardness, tensile properties and microstructure of the sintered strips were assessed. It was found that near-full densities, between 96 and 99%, are attainable after 30–90 min of sintering. The optimum sintering temperature range was found to be 1100–1200 °C, as this produced the highest elongation of 4–5.5%. Sintering at 1300 °C resulted in lower elongation due to higher contaminant pick-up.

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