scholarly journals Effect of the Processing Parameters on the Porosity and Mechanical Behavior of Titanium Samples with Bimodal Microstructure Produced via Hot Pressing

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 136
Author(s):  
Ricardo Chávez-Vásconez ◽  
Sheila Lascano ◽  
Sergio Sauceda ◽  
Mauricio Reyes-Valenzuela ◽  
Christopher Salvo ◽  
...  
Keyword(s):  
Hot Pressing ◽  
Processing Parameters ◽  
Ammonium Bicarbonate ◽  
Bimodal Microstructure ◽  
Electron Microscopies ◽  
Commercially Pure ◽  
Gas Atmosphere ◽  
Powder Particles ◽  
Titanium Grade ◽  
Milled Powders

Commercially pure (c.p.) titanium grade IV with a bimodal microstructure is a promising material for biomedical implants. The influence of the processing parameters on the physical, microstructural, and mechanical properties was investigated. The bimodal microstructure was achieved from the blends of powder particles with different sizes, while the porous structure was obtained using the space-holder technique (50 vol.% of ammonium bicarbonate). Mechanically milled powders (10 and 20 h) were mixed in 50 wt.% or 75 wt.% with c.p. titanium. Four different mixtures of powders were precompacted via uniaxial cold pressing at 400 MPa. Then, the specimens were sintered at 750 °C via hot pressing in an argon gas atmosphere. The presence of a bimodal microstructure, comprised of small-grain regions separated by coarse-grain ones, was confirmed by optical and scanning electron microscopies. The samples with a bimodal microstructure exhibited an increase in the porosity compared with the commercially available pure Ti. In addition, the hardness was increased while the Young’s modulus was decreased in the specimens with 75 wt.% of the milled powders (20 h).

UPM CP TITANIUM GRADE 3 (UNS R50550)

Alloy Digest ◽  
2020 ◽  
Vol 69 (6) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Pure Titanium ◽  
Heat Treating ◽  
Commercially Pure Titanium ◽  
Commercially Pure ◽  
Continuous Service ◽  
Pure Grade ◽  
Grade 3 ◽  
Titanium Grade ◽  
Design Stress

Abstract UPM CP Titanium Grade 3 (UNS R50550) is an unalloyed commercially pure titanium that exhibits moderate strength (higher strength than that of Titanium Grade 2), along with excellent formability and corrosion resistance. It offers the highest ASME allowable design stress of any commercially pure grade of titanium, and can be used in continuous service up to 425 °C (800 °F) and in intermittent service up to 540 °C (1000 °F). This datasheet provides information on composition, physical properties, and elasticity. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ti-167. Producer or source: United Performance Metals.

scholarly journals The Effects Of Friction On Stamping Process Of Sheet Metals Used In Aviation

2015 ◽  
Vol 60 (3) ◽  
pp. 1895-1900 ◽  
Author(s):  
K. Dyja ◽  
W. Więckowski
Keyword(s):  
Pure Titanium ◽  
Commercially Pure Titanium ◽  
Spherical Cap ◽  
Drawing Test ◽  
Commercially Pure ◽  
Stamping Process ◽  
Strip Drawing ◽  
Titanium Grade ◽  
The Impact ◽  
Lubrication Conditions

Abstract An important factor in the possibility of obtaining correct drawn parts with the desired functional properties is the friction between the stamped sheet and the tool. The article discusses the impact of technological lubricants developed according to our own formulas, based on vegetable oils, on the stamping process taking into account the strain distributions in the drawn parts. Biodegradable lubricants based on rapeseed oil with an addition of stearic acid or boric acid were used. The results of the friction coefficient in a strip drawing test and the numerical analysis results of the stamping process of a spherical cap from sheet metal: aluminium 2024, commercially pure titanium Grade 2, steel 5604 in dry friction and lubrication conditions, are presented. Strain distributions and changes in the drawn part wall thickness were analysed.

ATI CP GRADE 11 TITANIUM

Alloy Digest ◽  
2021 ◽  
Vol 70 (6) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Heat Treating ◽  
Chemical Processing ◽  
Commercially Pure ◽  
Excellent Corrosion Resistance ◽  
Continuous Service ◽  
The Media ◽  
Titanium Grade ◽  
Grade 11

Abstract ATI CP Grade 11 Titanium is an unalloyed titanium grade that contains 0.12-0.25% Pd. This palladium-containing alloy extends the range of application of commercially pure (CP) titanium in HCl, H3PO4, and H2SO4 solutions. ATI CP Grade 11 Titanium is used in applications requiring excellent corrosion resistance in chemical processing or storage applications where the media is mildly reducing or fluctuates between oxidizing and reducing. It can be used in continuous service up to 425 °C (795 °F) and in intermittent service up to 540 °C (1000 °F). This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, and joining. Filing Code: Ti-179. Producer or source: ATI.

scholarly journals Thromboinflammation as bioactivity assessment of H2O2-alkali modified titanium surfaces

2019 ◽  
Vol 30 (6) ◽  
Author(s):  
Gry Hulsart-Billström ◽  
Oscar Janson ◽  
Håkan Engqvist ◽  
Ken Welch ◽  
Jaan Hong
Keyword(s):  
Platelet Aggregation ◽  
Complement Activation ◽  
Pure Titanium ◽  
Commercially Pure Titanium ◽  
Coagulation Activation ◽  
Commercially Pure ◽  
A Cell ◽  
Modified Surface ◽  
Titanium Surfaces ◽  
Titanium Grade

Abstract The release of growth factors from platelets, mediated by the coagulation and the complement system, plays an important role in the bone formation around implants. This study aimed at exploring the thromboinflammatory response of H2O2-alkali soaked commercially pure titanium grade 2 discs exposed to whole human blood, as a way to assess the bioactivity of the discs. Commercially pure titanium grade 2 discs were modified by soaking in H2O2, NaOH and Ca(OH)2. The platelet aggregation, coagulation activation and complement activation was assessed by exposing the discs to fresh whole blood from human donors. The platelet aggregation was examined by a cell counter and the coagulation and complement activation were assessed by ELISA-measurements of the concentration of thrombin-antithrombin complex, C3a and terminal complement complex. The modified surface showed a statistically significant increased platelet aggregation, coagulation activation and complement activation compared to unexposed blood. The surface also showed a statistically significant increase of coagulation activation compared to PVC. The results of this study showed that the H2O2-alkali soaked surfaces induced a thromboinflammatory response that indicates that the surfaces are bioactive.

Liquid supercoolings and droplet cooling rates of remelted argon-atomized Fe–30Ni powder particles

1988 ◽  
Vol 3 (3) ◽  
pp. 441-452 ◽  
Author(s):  
Matthew R. Libera ◽  
Pedro P. Bolsaitis ◽  
R. Erik Spjut ◽  
John B. VanderSande
Keyword(s):  
Standard Deviation ◽  
Cooling Rate ◽  
Metal Droplet ◽  
Liquid Droplets ◽  
Interfacial Velocity ◽  
Gas Atmosphere ◽  
History Of ◽  
Powder Particles ◽  
The Difference ◽  
Individual Particles

Individual particles of argon-atomized Fe-30Ni powder are electrodynamically levitated and remelted by a CO2 laser pulse. The thermal history of each droplet during remelting and solidification is monitored by single-color radiation pyrometry at each of three wavelengths (850, 750, and 550 nm). Experiments are done in an atmosphere of either air or nitrogen. The average supercooling of six experiments performed in nitrogen is 298 K with a standard deviation of 14 K. This value is of the same order as several others reported in the literature using bulk levitation and emulsification techniques. The average supercooling of seven experiments performed in air is 163 K with a standard deviation of 20 K. The difference suggests that oxides are forming in the air-remelting experiments and catalyzing nucleation at relatively low supercoolings. The average cooling rate of the liquid droplets prior to solidification in nitrogen is 1.5 × 105 K/s. This measured cooling rate is somewhat higher than that predicted by Newtonian heat flow modeling, and the difference is attributed to radiative losses not considered in the Newtonian model. The measured cooling rate is used to estimate the total heat transfer coefficient characterizing cooling of a small metal droplet in a quiescent gas atmosphere. A lower bound of 1.5 × 106 K/s on the droplet heating rate during recalescence and a minimum average liquid/solid interfacial velocity during recalescence of 0.1 m/s are estimated.

Theoretical Analysis of Porosity in an Ordered Porous Copper Fabricated by Continuous Unidirectional Solidification

2018 ◽  
Vol 933 ◽  
pp. 136-141
Author(s):  
Rong Cao ◽  
Qing Lin Jin
Keyword(s):  
High Pressure ◽  
Theoretical Model ◽  
Theoretical Analysis ◽  
Processing Parameters ◽  
Unidirectional Solidification ◽  
Hydrogen Gas ◽  
Porous Copper ◽  
Gas Atmosphere ◽  
Ordered Porous ◽  
Good Agreement

Ordered porous copper with elongated pores has been fabricated by a continuous unidirectional solidification method in a hydrogen gas atmosphere with high pressure. The porosity of the ordered porous copper is significantly affected by the pressure of hydrogen. A theoretical model is developed to get the relation between the porosity and the processing parameters. The calculated values are in good agreement with the experimental results. Key words: Unidirectional solidification; Ordered porous copper; Porosity; Modeling.

Microstructure and thermoelectric properties of Ga-DOPED SiGe alloys prepared by mechanical alloying and induction hot pressing

2014 ◽  
Vol 07 (02) ◽  
pp. 1450008 ◽  
Author(s):  
Shanshan Lin ◽  
Chunlin Wang ◽  
Haiyan Chen ◽  
Dexuan Huo ◽  
Nick Savvides ◽  
...  
Keyword(s):  
Ball Milling ◽  
Hot Pressing ◽  
High Energy ◽  
Solid Solution Phase ◽  
Nominal Composition ◽  
Mill Time ◽  
Composition Property ◽  
Energy Ball ◽  
P Type ◽  
Milled Powders

Ga -doped SiGe alloys were prepared by high energy ball milling followed by induction hot pressing. The grain size decreases dramatically with increasing mill time, and nanostructured features in the range 3–500 nm were introduced after extensive ball milling for 2–12 h. The bulk alloys hot pressed from 2 h and 6 h dry-milled powders consist of different compositions of micron- to nanosized Si y Ge 100-y, where Ga prefers to locate in the submicron- and nanosized Ge -rich phase and form a modulation-doping structure. The samples hot pressed from 12 h wet-milled powders are more homogeneous in microstructure and composition. Property characterization shows that although Ga -doping leads to p-type conduction, only part of Ga atoms is incorporated as dopant in the SiGe solid solution phase. Samples hot pressed from 2 h and 6 h dry-milled powders have higher power factors, while those hot pressed from 12 h wet-milled powders posses much lower thermal conductivity. The maximum figure of merit (ZT) is 0.51 at 805°C for the 6 h dry-milled and hot pressed sample with the nominal composition Si 80 Ge 18 Ga 2.

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