scholarly journals Effect of Line Energy Conditions on Mechanical and Fatigue Properties of Ti6Al4V Fabricated by Electron Beam Additive Manufacturing

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 878
Author(s):  
Youngsin Choi ◽  
Hwi-Jun Kim ◽  
Gun-Hee Kim ◽  
Chang-Woo Lee ◽  
Dong-Geun Lee
Keyword(s):  
Electron Beam ◽  
Additive Manufacturing ◽  
Fatigue Strength ◽  
Energy Conditions ◽  
Fatigue Properties ◽  
Process Conditions ◽  
Main Process ◽  
Process Variables ◽  
Line Energy ◽  
Scan Speed

Additive manufacturing has many process variables and requires additive process optimization. Line energy and scan speed are the main process variables. The objective of this work aims to investigate the effect of changes in line energy and scan speed among the process variables on the mechanical and fatigue properties of the Ti6Al4V specimens fabricated by electron beam additive manufacturing method. The size of the pore inside the specimen was 40~60 μm with the exception of the condition of 0.2 kJ/m, and the specimen with poor fusion of more than 100 μm and gas pore was found to have lower room temperature tensile and fatigue properties compared to the optimal process conditions. As line energy increased, strain hardening occurred, and yield strength and tensile strength increased. The EL:0.3 kJ/m and 800 mm/s condition is a process condition that shows no defects such as unmelted powder and poor fusion, and it represents the best fatigue strength of 400 MPa. The fatigue strength of the specimen performed with hot isostatic pressing after additive manufacturing was measured at 550 MPa, an increase of 150 MPa, which resulted in high fatigue strength enhancement. The crack initiation site and propagation behavior were analyzed by observing the fatigue fracture section of the specimen according to the line energy.

Microstructure and Fatigue Properties of TiAl with Unique Layered Microstructure Fabricated by Electron Beam Melting

2018 ◽  
Vol 941 ◽  
pp. 1597-1602
Author(s):  
Ken Cho ◽  
Ryota Kobayashi ◽  
Takuma Fukuoka ◽  
Jong Yeong Oh ◽  
Hiroyuki Y. Yasuda ◽  
...  
Keyword(s):  
Electron Beam ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Crack Propagation ◽  
Electron Beam Melting ◽  
Low Cycle Fatigue ◽  
Hot Isostatic Pressing ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Cast Alloys

The effect of a unique layered microstructure consisting of duplex-like region and equiaxed γ grains (γ bands) on the fatigue properties of Ti-48Al-2Cr-2Nb alloy bars fabricated by electron beam melting (EBM) at an angle (θ) of 90° between the building direction and cylinder (loading) axis was investigated focusing on the layered microstructure and test temperature. We found the room temperature (RT) fatigue strength of the alloy bars fabricated at θ = 90° is higher than that of the bars fabricated at θ = 0°. Moreover, it is comparable to that of the cast alloys with hot isostatic pressing (HIP) treatment in low-cycle fatigue life region, even without HIP treatment. The high fatigue strength of the bars at RT is attributed to the γ band, which acts as a resistance for crack propagation directed perpendicular to the γ band. On the other hand, the fatigue strength of the bars at θ = 90° is lower than that of the bars at θ = 0° in low-cycle fatigue life region at 1023 K. This is because the γ bands dose not act as a resistance for crack propagation at 1023 K. Although the bars at θ = 90° exhibits low fatigue strength in the region at 1023 K, that value is comparable to that of HIP-treated cast alloys due to the fine grain size, which is one of the features for the alloys fabricated by the EBM.

scholarly journals Evaluation of Support Structure Removability for Additively Manufactured Ti6Al4V Overhangs via Electron Beam Melting

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1211 ◽  
Author(s):  
Wadea Ameen ◽  
Muneer Khan Mohammed ◽  
Abdulrahman Al-Ahmari
Keyword(s):  
Electron Beam ◽  
Additive Manufacturing ◽  
Process Parameters ◽  
Electron Beam Melting ◽  
Beam Current ◽  
Design Parameters ◽  
Support Structures ◽  
Support Design ◽  
Removal Time ◽  
Scan Speed

The addition of support structures is essential for the successful fabrication of overhang structures through additive manufacturing (AM). The support structures protect the overhang portion from distortions. They are fabricated with the functional parts and are removed later after the fabrication of the AM part. While structures bearing insufficient support result in defective overhangs, structures with excessive support result in higher material consumption, time and higher post-processing costs. The objective of this study is to investigate the effects of design and process parameters of support structures on support removability during the electron beam melting (EBM)-based additive manufacturing of the Ti6Al4V overhang part. The support design parameters include tooth parameters, no support offset, fragmentation parameters and perforation parameters. The EBM process parameters consist of beam current, beam scan speed and beam focus offset. The results show that both support design and process parameters have a significant effect on support removability. In addition, with the appropriate selection of design and process parameters, it is possible to significantly reduce the support removal time and protect the surface quality of the part.

Fatigue properties of AlSi10Mg obtained by additive manufacturing: Defect-based modelling and prediction of fatigue strength

2018 ◽  
Vol 187 ◽  
pp. 165-189 ◽  
Author(s):  
S. Romano ◽  
A. Brückner-Foit ◽  
A. Brandão ◽  
J. Gumpinger ◽  
T. Ghidini ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Fatigue Strength ◽  
Fatigue Properties

Electron Beam Additive Manufacturing of Titanium Components: Properties and Performance

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
P. Edwards ◽  
A. O'Conner ◽  
M. Ramulu
Keyword(s):  
Fracture Toughness ◽  
Residual Stress ◽  
Electron Beam ◽  
Additive Manufacturing ◽  
Static Strength ◽  
Fatigue Performance ◽  
Fatigue Properties ◽  
Post Processing ◽  
Premature Failure ◽  
And Performance

This research evaluates the fatigue properties of Ti-6Al-4V specimens and components produced by Electron Beam additive manufacturing. It was found that the fatigue performance of specimens produced by additive manufacturing is significantly lower than that of wrought material due to defects such as porosity and surface roughness. However, evaluation of an actual component subjected to design fatigue loads did not result in premature failure as anticipated by specimen testing. Metallography, residual stress, static strength and elongation, fracture toughness, crack growth, and the effect of post processing operations such as machining and peening on fatigue performance were also evaluated.

scholarly journals Titanium Alloy Repair with Wire-Feed Electron Beam Additive Manufacturing Technology

2019 ◽  
Vol 2019 ◽  
pp. 1-23 ◽  
Author(s):  
P. Wanjara ◽  
K. Watanabe ◽  
C. de Formanoir ◽  
Q. Yang ◽  
C. Bescond ◽  
...  
Keyword(s):  
Electron Beam ◽  
Additive Manufacturing ◽  
Three Dimensional ◽  
Manufacturing Technology ◽  
Image Correlation ◽  
Fatigue Properties ◽  
Wall Structure ◽  
Operational Environment ◽  
Additive Manufacturing Technology ◽  
Wire Feed

Wire feeding can be combined with different heat sources, for example, arc, laser, and electron beam, to enable additive manufacturing and repair of metallic materials. In the case of titanium alloys, the vacuum operational environment of electron beam systems prevents atmospheric contamination during high-temperature processing and ensures high performance and reliability of additively manufactured or repaired components. In the present work, the feasibility of developing a repair process that emulates refurbishing an “extensively eroded” fan blade leading edge using wire-feed electron beam additive manufacturing technology was examined. The integrity of the Ti6Al4V wall structure deposited on a 3 mm thick Ti6Al4V substrate was verified using X-ray microcomputed tomography with a three-dimensional reconstruction. To understand the geometrical distortion in the substrate, three-dimensional displacement mapping with digital image correlation was undertaken after refurbishment and postdeposition stress relief heat treatment. Other characteristics of the repair were examined by assessing the macro- and microstructure, residual stresses, microhardness, tensile and fatigue properties, and static and dynamic failure mechanisms.

Additiv hergestellter Drehklemmhalter*/Additively manufactured turning tool holder - Fatigue strength of additive tool structures and open jet formation of cryogenic multi-component cooling

2018 ◽  
Vol 108 (01-02) ◽  
pp. 102-108
Author(s):  
E. Prof. Abele ◽  
T. Heep ◽  
C. Bickert ◽  
B. Prof. Pyttel ◽  
K. Kirilov
Keyword(s):  
Heat Treatment ◽  
Additive Manufacturing ◽  
Fatigue Strength ◽  
Functional Integration ◽  
Fatigue Properties ◽  
Material Structure ◽  
Manufacturing Processes ◽  
Jet Formation ◽  
Innovative Tool ◽  
Two Fluid

Additive Fertigungsverfahren gestatten die Herstellung innovativer Werkzeugsysteme mit erhöhter Funktionsintegration. Die vorliegende Arbeit liefert wichtige Erkenntnisse in Bezug auf additiv gefertigte Drehklemmhalter. Zum einen wird der Einfluss der Wärmebehandlung auf das Werkstoffgefüge und schlussendlich auf die Schwingfestigkeitseigenschaften untersucht. Zum anderen wird der Einfluss additiv hergestellter Zweistoffdüsen auf das resultierende Freistrahlverhalten experimentell ermittelt.   Additive manufacturing processes allow producing innovative tool systems associated with increased functional integration. This work provides important insights on additively manufactured turning tool holders. Firstly, it investigates how heat treatment affects both material structure and fatigue properties. Secondly, it determines experimentally how additively produced two-fluid nozzles influence the resulting open jet formation.

A Procedure for Determining the Operating Modes of Electron Beam Wire Feed Layer-Wise Deposition for Additive Manufacturing

Vestnik MEI ◽  
2017 ◽  
pp. 8-14 ◽  
Author(s):  
Aleksandr V. Gudenko ◽  
◽  
Viktor К. Dragunov ◽  
Andrey Р. Sliva ◽  
◽  
...  
Keyword(s):  
Electron Beam ◽  
Additive Manufacturing ◽  
Operating Modes ◽  
Wire Feed

CHEMICAL PULPING. Oxidative degradation of AOX in softwood-based kraft mill effluents from E C F bleachin g

2012 ◽  
Vol 27 (4) ◽  
pp. 707-713 ◽  
Author(s):  
Jukka Pekka lsoaho ◽  
Suvi Tarkkanen ◽  
Raimo Alen ◽  
Juha Fiskari
Keyword(s):  
Reaction Time ◽  
Oxidative Degradation ◽  
Cost Effective ◽  
Process Conditions ◽  
Main Process ◽  
Chemical Pulping ◽  
Kraft Mill ◽  
Organic Halogens ◽  
Aox Removal ◽  
Adsorbable Organic Halogens

Abstract Softwood-based kraft mill bleaching effluents from the initial bleaching stages D0 and E1 (the bleaching sequence being D0E 1D 1 E2D2) were treated by the oxidative Fenton method (H20rFeS04) to decompose organic pollutants contammg adsorbable organic halogens (AOX). Experiments designed using the Taguchi method were applied to predict the process conditions that would result in a cost-effective and adequate removal of AOX. In addition to the composition and concentration of the reagents (H202 and Fe2+), the main process parameters selected were temperature and reaction time, while pH was adj usted to an approximate value of 4 (the volumetric ratio of the mixed effluents D0:E 1 was 3 :2). The results indicated that an AOX removal of about 70% for this mixture ( corresponding to about 50% for the mill) was achieved when the eftluent samples were treated for 60 min at 70°C with H202 and Fe2+ at a concentration of 1 600 mg/1 and 28 mg/1, respectively.

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