scholarly journals Lubricant Influence on the Ejection and Roughness of In-Die Electro Sinter Forged Ti-Discs

2018 ◽  
Vol 767 ◽  
pp. 171-178 ◽  
Author(s):  
Emanuele Cannella ◽  
Chris Valentin Nielsen
Keyword(s):  
Surface Defects ◽  
Pure Titanium ◽  
Roughness Parameter ◽  
Axial Loading ◽  
Electrical Current ◽  
Radial Pressure ◽  
Sintered Sample ◽  
Commercially Pure Titanium ◽  
Mechanical Pressure ◽  
Sinter Forging

Electro Sinter Forging (ESF) is a new sintering process based on Joule heating by high electrical current flowing through compacted metal powder under mechanical pressure. The whole process takes about three seconds and is based on a closed-die setup, where the sample is sintered inside a die. A near-net shape component is therefore manufactured. One of the challenges associated with this process is the ejection of the sample after sintering. Due to powder compaction and axial loading during sintering, a radial pressure is generated at the die/sample interface. Consequently, the ejection can be difficult, and the final quality of the sintered component in terms of roughness and surface defects may be affected. In the present work, four different lubricants and non-lubricated conditions were tested to investigate the effects on the final part quality. The sintered sample is a disc made of commercially pure titanium powder. The force was measured while ejecting the samples by using a speed-controlled press. The surface roughness parameter Sa was measured by using a laser confocal microscope.

scholarly journals Electro Sinter Forging (ESF)

Micromachines ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 218 ◽  
Author(s):  
Emanuele Cannella ◽  
Chris Valentin Nielsen ◽  
Niels Bay
Keyword(s):  
Process Parameters ◽  
Compaction Pressure ◽  
Pure Titanium ◽  
Electrical Current ◽  
Main Process ◽  
Commercially Pure Titanium ◽  
Electrical Currents ◽  
Sinter Forging ◽  
Sintering Time ◽  
Electrical Current Density

Electro sinter forging (ESF) represents an innovative manufacturing process dealing with high electrical currents. Classified in the category of electrical current assisted sintering (ECAS) processes, the main principle is that Joule heating is generated inside the compacted powder, while the electrical current is flowing. The process is optimized through the analysis of the main process parameters, namely the electrical current density, sintering time, and compaction pressure, which are also evaluated as process fingerprints. The analysis was conducted on commercially pure titanium powder. Small discs and rings were manufactured for testing. The influence of the process parameters was analysed in terms of the final material properties. The relative density, microstructures, hardness, and tensile and compressive strengths were analysed concerning their validity as product fingerprints. Microstructural analyses revealed whether the samples were sintered or if melting had occurred. Mechanical properties were correlated to the process parameters depending on the material. The different sample shapes showed similar trends in terms of the density and microstructures as a function of the process parameters.

scholarly journals Impact of machining-induced surface defects on the edge formability of commercially pure titanium sheet at room temperature

2020 ◽  
Vol 2 (12) ◽  
Author(s):  
J. S. Kwame ◽  
E. Yakushina ◽  
P. Blackwell
Keyword(s):  
Room Temperature ◽  
Surface Defects ◽  
Pure Titanium ◽  
Commercially Pure Titanium ◽  
Hole Expansion ◽  
Expansion Test ◽  
Hole Expansion Test ◽  
Edge Surface ◽  
Cp Ti ◽  
The Impact

AbstractDespite the good properties of titanium, which have drawn the interest of various industries over the years, one of the major drawbacks of this material is its poor machinability. This has largely been attributed to its low thermal conductivity and elastic modulus. The ability to attain the optimum sheet edge performance during forming is dependent on the quality of the edges produced. Also, the demanding nature of aerospace part design has provoked the interest of both industry and academia to continually explore avenues tailored at enhancing part performance. The sort of edge surface integrity produced for aerospace part fabrication thus becomes a vital consideration in the quest to ensuring prime performance of components. This work seeks to study the influence of different machining-induced surface defects on the sheet edge performance of CP-Ti (grade 2) at room temperature. Hole expansion test was used to assess the edge surface formability of CP-Ti with different machining-induced edge defects. The research found that machining-induced surface defects act as stress concentration sites during the hole expansion test and have a major impact on the material flow. Electro-discharge machined edges were observed to exhibit high edge formability compared to laser and abrasive water jet cut edges due to the impact of machining-induced microstructural changes.

scholarly journals Study on Grinding and Deformation Fracture Control of Cold Rolled Titanium Strip

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 323 ◽  
Author(s):  
Jiaming Zhang ◽  
Wei Yu ◽  
Entao Dong ◽  
Zeyu Zhang ◽  
Jiaxin Shi ◽  
...  
Keyword(s):  
Tensile Stress ◽  
Cold Rolling ◽  
Surface Defects ◽  
True Strain ◽  
Rolling Direction ◽  
Pure Titanium ◽  
Stress And Strain ◽  
Commercially Pure Titanium ◽  
Maximum Tensile Strain ◽  
Rolling Deformation

Surface defects of titanium strip need to be removed by local grinding, but local cracking or band breaking then occurs during subsequent cold rolling. Tensile properties and deformation resistance of 3 mm thick commercially pure titanium strip with grinding pits on the surface were simulated by a finite-element method using a multi-pass cold-rolling deformation process. The stress and strain of grinding pits with depths of 0.25–2 mm were analyzed. During cold-rolling deformation, the stress and strain in the center of a grinding pit were larger than at the edge region. The strip was first subjected to tensile stress in the rolling direction, which then decreased and gradually changed to compressive stress. Partial stress was larger in the rolling direction than in the transverse direction. When the tensile stress and true strain both exceeded the stress and strain limits during second-pass rolling, the strip with a grinding depth of 2 mm cracked, but shallower grinding pits were repaired. The criterion for cracking during rolling after grinding is that the maximum tensile strain at the bottom of the pit must be less than the critical strain of the material: ln ( 1 + h / H ) ≤ ε C r . Results of numerical simulation were verified by the data for cold-rolling tests.

RMI 0.2% Pd

Alloy Digest ◽  
1979 ◽  
Vol 28 (12) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Crevice Corrosion ◽  
Elevated Temperatures ◽  
Pure Titanium ◽  
Heat Treating ◽  
Low Ph ◽  
Commercially Pure Titanium ◽  
Bend Strength ◽  
Commercially Pure ◽  
Minimum Yield

Abstract RMI 0.2% Pd is a grade of commercially pure titanium to which up to 0.2% palladium has been added. It has a guaranteed minimum yield strength of 40,000 psi with good ductility and formability. It is recommended for corrosion resistance in the chemical industry and other places where the environment is mildly reducing or varies between oxidizing and reducing. The alloy has improved resistance to crevice corrosion at low pH and elevated temperatures. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and bend strength. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ti-74. Producer or source: RMI Company.

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.

In vitro Behaviour of Alumina-Hydroxiapatite Composites Coatings

2018 ◽  
Vol 69 (6) ◽  
pp. 1416-1418
Author(s):  
Alexandru Szabo ◽  
Ilare Bordeasu ◽  
Ion Dragos Utu ◽  
Ion Mitelea
Keyword(s):  
Pure Titanium ◽  
Titanium Substrate ◽  
High Strength ◽  
Biological Properties ◽  
Commercially Pure Titanium ◽  
Hvof Spraying ◽  
Before And After ◽  
Sbf Solution ◽  
Oxygen Fuel

Hydroxyapatite (HA) is a very common material used for biomedical applications. Usually, in order to improve its poor mechanical properties is combined or coated with other high-strength materials.The present paper reports the manufacturing and the biocompatibility behaviour of two different biocomposite coatings consisting of alumina (Al2O3) and hydroxyapatite (HA) using the high velocity oxygen fuel (HVOF) spraying method which were deposited onto the surface of a commercially pure titanium substrate. The biological properties of the Al2O3-HA materials were evaluated by in vitro studies. The morphology of the coatings before and after their immersing in the simulated body fluid (SBF) solution was characterized by scanning electron microscopy (SEM). The results showed an important germination of the biologic hydroxyapatite crystallite on the surface of both coatings.

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