Effect of reheating zones in additive manufacturing by means of electron beam metal wire deposition method

AbstractThe complex thermal cycles and temperature distributions observed in additive manufacturing (AM) are of particular interest as these define the microstructure and the associated properties of the part being built. Due to the intrinsic, layer-by-layer material stacking performed, contact methods to measure temperature are not suitable, and contactless methods need to be considered. Contactless infrared irradiation techniques were applied by carrying out thermal imaging and point measurement methods using pyrometers to determine the spatial and temporal temperature distribution in wire-based electron beam AM. Due to the vacuum, additional challenges such as element evaporation must be overcome and additional shielding measures were taken to avoid interference with the contactless techniques. The emissivities were calibrated by thermocouple readings and geometric boundary conditions. Thermal cycles and temperature profiles were recorded during deposition; the temperature gradients are described and the associated temperature transients are derived. In the temperature range of the α+β field, the cooling rates fall within the range of 180 to 350 °C/s, and the microstructural characterisation indicates an associated expected transformation of β→α'+α with corresponding cooling rates. Fine acicular α and α’ formed and local misorientation was observed within α as a result of the temperature gradient and the formation of the α’.

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Structure and mechanical properties of ferritic-pearlite steel printed by electron beam additive manufacturing

10.1063/5.0034189 ◽

2020 ◽

Author(s):

N. N. Shamarin ◽

Yu. V. Kushnarev ◽

A. V. Filippov ◽

S. Yu. Tarasov

Keyword(s):

Mechanical Properties ◽

Electron Beam ◽

Additive Manufacturing

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An experimental study of the wear resistance of ferrite-pearlite steel printed by electron beam additive manufacturing

10.1063/5.0034186 ◽

2020 ◽

Author(s):

N. N. Shamarin ◽

Yu. V. Kushnarev ◽

A. V. Filippov ◽

S. Yu. Tarasov

Keyword(s):

Experimental Study ◽

Wear Resistance ◽

Electron Beam ◽

Additive Manufacturing

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Directionally-Dependent Mechanical Properties of Ti6Al4V Manufactured by Electron Beam Melting (EBM) and Selective Laser Melting (SLM)

Materials ◽

10.3390/ma14133603 ◽

2021 ◽

Vol 14 (13) ◽

pp. 3603

Author(s):

Tim Pasang ◽

Benny Tavlovich ◽

Omry Yannay ◽

Ben Jakson ◽

Mike Fry ◽

...

Keyword(s):

Mechanical Properties ◽

Surface Roughness ◽

Tensile Strength ◽

Electron Beam ◽

Additive Manufacturing ◽

Selective Laser Melting ◽

Electron Beam Melting ◽

Rolling Direction ◽

Laser Melting ◽

Plate Rolling

An investigation of mechanical properties of Ti6Al4V produced by additive manufacturing (AM) in the as-printed condition have been conducted and compared with wrought alloys. The AM samples were built by Selective Laser Melting (SLM) and Electron Beam Melting (EBM) in 0°, 45° and 90°—relative to horizontal direction. Similarly, the wrought samples were also cut and tested in the same directions relative to the plate rolling direction. The microstructures of the samples were significantly different on all samples. α′ martensite was observed on the SLM, acicular α on EBM and combination of both on the wrought alloy. EBM samples had higher surface roughness (Ra) compared with both SLM and wrought alloy. SLM samples were comparatively harder than wrought alloy and EBM. Tensile strength of the wrought alloy was higher in all directions except for 45°, where SLM samples showed higher strength than both EBM and wrought alloy on that direction. The ductility of the wrought alloy was consistently higher than both SLM and EBM indicated by clear necking feature on the wrought alloy samples. Dimples were observed on all fracture surfaces.

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Effect of Filler Metal Type on Microstructure and Mechanical Properties of Fabricated NiAl Bronze Alloy Using Wire Arc Additive Manufacturing System

Metals ◽

10.3390/met11030513 ◽

2021 ◽

Vol 11 (3) ◽

pp. 513

Author(s):

Jae Won Kim ◽

Jae-Deuk Kim ◽

Jooyoung Cheon ◽

Changwook Ji

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Additive Manufacturing ◽

Filler Metal ◽

Gas Metal Arc Welding ◽

Metal Wire ◽

Cold Metal Transfer ◽

Metal Type ◽

Cold Metal ◽

Wire Arc Additive Manufacturing

This study observed the effect of filler metal type on mechanical properties of NAB (NiAl-bronze) material fabricated using wire arc additive manufacturing (WAAM) technology. The selection of filler metal type is must consider the field condition, mechanical properties required by customers, and economics. This study analyzed the bead shape for representative two kind of filler metal types use to maintenance and fabricated a two-dimensional bulk NAB material. The cold metal transfer (CMT) mode of gas metal arc welding (GMAW) was used. For a comparison of mechanical properties, the study obtained three specimens per welding direction from the fabricated bulk NAB material. In the tensile test, the NAB material deposited using filler metal wire A showed higher tensile strength and lower elongation (approx. +71 MPa yield strength, +107.1 MPa ultimate tensile strength, −12.4% elongation) than that deposited with filler metal wire B. The reason is that, a mixture of tangled fine α platelets and dense lamellar eutectoid α + κIII structure with β´ phases was observed in the wall made with filler metal wire A. On the other hand, the wall made with filler metal wire B was dominated by coarse α phases and lamellar eutectoid α + κIII structure in between.

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