On the influence of silicon on the growth of the alloy layer during hot dip aluminizing

Eggeler, Gunther; Auer, W.; Kaesche, Helmut

doi:10.1007/bf00553379

Cited by 146 publications

(100 citation statements)

References 4 publications

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“…These lightly pre-welded samples were then isothermally annealed in the temperature range 673 K to 843 K (400°C to 570°C ) for times increasing up to 8 hours. Metallographic cross sections were prepared from the welded and heat-treated samples by grinding and polishing, using standard techniques, before observation Bouayad et al [13] 74.1 1073 (800) pure Al*-pure Fe Denner and Jones [14] 170-195 1044 (771) pure Al*-Mild steel Eggeler et al [15] 34-155 1059 (786) pure Al*-Low carbon steel Naoi et al [6] 281 873-923 (600-650) pure Al-pure Fe Springer et al [3] 190 873 (600) pure aluminum-low-carbon steel Tang et al [16] 123 953-1043 (680-770) pure Al*-pure Fe by scanning electron microscopy (SEM) using a high-resolution FEI Magellan field emission gun (FEG) microscope. The average layer thickness was determined from the net area of the IMC layer divided by the interface length.…”

Section: Methodsmentioning

confidence: 99%

The Influence of Grain Structure on Intermetallic Compound Layer Growth Rates in Fe-Al Dissimilar Welds

Robson

Wang

et al. 2017

Metall Mater Trans A

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The thickness of the intermetallic compound (IMC) layer that forms when aluminum is welded to steel is critical in determining the properties of the dissimilar joints. The IMC reaction layer typically consists of two phases (g and h) and many attempts have been made to determine the apparent activation energy for its growth, an essential parameter in developing any predictive model for layer thickness. However, even with alloys of similar composition, there is no agreement of the correct value of this activation energy. In the present work, the IMC layer growth has been characterized in detail for AA6111 aluminum to DC04 steel couples under isothermal annealing conditions. The samples were initially lightly ultrasonically welded to produce a metallic bond, and the structure and thickness of the layer were then characterized in detail, including tracking the evolution of composition and grain size in the IMC phases. A model developed previously for Al-Mg dissimilar welds was adapted to predict the coupled growth of the two phases in the layer, whilst accounting explicitly for grain boundary and lattice diffusion, and considering the influence of grain growth. It has been shown that the intermetallic layer has a submicron grain size, and grain boundary diffusion as well as grain growth plays a critical role in determining the thickening rate for both phases. The model was used to demonstrate how this explains the wide scatter in the apparent activation energies previously reported. From this, process maps were developed that show the relative importance of each diffusion path to layer growth as a function of temperature and time.

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Section: Methodsmentioning

confidence: 99%

The Influence of Grain Structure on Intermetallic Compound Layer Growth Rates in Fe-Al Dissimilar Welds

Robson

Wang

et al. 2017

Metall Mater Trans A

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“…The reactive diffusion between liquid Al and solid Fe or Fe-base alloys has been experimentally studied by many researchers. [62][63][64][65][66][67][68][69][70][71][72] In an experiment by Bouché et al, 69) Fe/Al diffusion couples were prepared by a melt bath technique, and then isothermally annealed at temperatures of 973-1173 K. A similar experiment was conducted by Bouayad et al 71) In the binary Fe-Al system, 1) FeAl 3 , Fe 2 Al 5 , FeAl 2 and FeAl are the stable compounds at these temperatures. According to their experimental results, 69,71) however, only Fe 2 Al 5 and FeAl 3 are formed as visible layers at the Fe/Al interface in the diffusion couple owing to annealing.…”

Section: Introductionmentioning

confidence: 99%

Morphology of Compounds Formed by Isothermal Reactive Diffusion between Solid Fe and Liquid Al

Tanaka

Kajihara

2009

Mater. Trans.

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“…[56] Several studies revealed that in particular silicon (Si) additions to aluminum melts decelerate the growth and reduce the thickness of the IM layer forming on steel samples hot dipped into the melts. [36,40,[51][52][53][54] The same effect was observed in dissimilar welding of aluminum alloys with steel using Al-Si-based fillers. [10,19,57] Although the influence of silicon on the growth of the IM layer is still not completely understood, it is assumed that the diffusivity of aluminum atoms in the solid Al 5 Fe 2 phase is significantly reduced due to the occupation of vacancy sites by silicon atoms, [40,52] or that silicon reduces the activity coefficient of aluminum atoms in iron at the Al-Fe interface.…”

Section: Introductionmentioning

confidence: 79%

“…[36,40,[51][52][53][54] The same effect was observed in dissimilar welding of aluminum alloys with steel using Al-Si-based fillers. [10,19,57] Although the influence of silicon on the growth of the IM layer is still not completely understood, it is assumed that the diffusivity of aluminum atoms in the solid Al 5 Fe 2 phase is significantly reduced due to the occupation of vacancy sites by silicon atoms, [40,52] or that silicon reduces the activity coefficient of aluminum atoms in iron at the Al-Fe interface. [56] The main objective of this study was to investigate the influences of different filler alloy compositions and process parameters on the thickness of the IM layer.…”

Section: Introductionmentioning

confidence: 81%

“…[20,21] Among the Al x Fe y phases listed in the binary Al-Fe phase diagram, [35] two main phases were identified in laboratory experiments to form at the interface between solid iron or steel and liquid aluminum or its alloys: Al 5 Fe 2 as the major g-phase [36][37][38] together with Al 3 Fe (also referred to as Al 13 Fe 4 ) as the minor h-phase. [39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55] Both [17][18][19]21,24,27,29] or at least either one [22,23] of these two phases were also found to form during dissimilar CMT welding of aluminum alloys with steel. These experimental studies also show that the interfaces are typically tongue-like between Al 5 Fe 2 and steel, whereas they are finely serrated between Al 3 Fe and aluminum.…”

Section: Introductionmentioning

confidence: 99%

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Influence of Filler Alloy Composition and Process Parameters on the Intermetallic Layer Thickness in Single-Sided Cold Metal Transfer Welding of Aluminum-Steel Blanks

Silvayeh

Vallant

Sommitsch

et al. 2017

Metall Mater Trans A

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Hybrid components made of aluminum alloys and high-strength steels are typically used in automotive lightweight applications. Dissimilar joining of these materials is quite challenging; however, it is mandatory in order to produce multimaterial car body structures. Since especially welding of tailored blanks is of utmost interest, single-sided Cold Metal Transfer butt welding of thin sheets of aluminum alloy EN AW 6014 T4 and galvanized dual-phase steel HCT 450 X + ZE 75/75 was experimentally investigated in this study. The influence of different filler alloy compositions and welding process parameters on the thickness of the intermetallic layer, which forms between the weld seam and the steel sheet, was studied. The microstructures of the weld seam and of the intermetallic layer were characterized using conventional optical light microscopy and scanning electron microscopy. The results reveal that increasing the heat input and decreasing the cooling intensity tend to increase the layer thickness. The silicon content of the filler alloy has the strongest influence on the thickness of the intermetallic layer, whereas the magnesium and scandium contents of the filler alloy influence the cracking tendency. The layer thickness is not uniform and shows spatial variations along the bonding interface. The thinnest intermetallic layer (mean thickness < 4 lm) is obtained using the silicon-rich filler Al-3Si-1Mn, but the layer is more than twice as thick when different low-silicon fillers are used.

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On the influence of silicon on the growth of the alloy layer during hot dip aluminizing

Cited by 146 publications

References 4 publications

The Influence of Grain Structure on Intermetallic Compound Layer Growth Rates in Fe-Al Dissimilar Welds

The Influence of Grain Structure on Intermetallic Compound Layer Growth Rates in Fe-Al Dissimilar Welds

Morphology of Compounds Formed by Isothermal Reactive Diffusion between Solid Fe and Liquid Al

Influence of Filler Alloy Composition and Process Parameters on the Intermetallic Layer Thickness in Single-Sided Cold Metal Transfer Welding of Aluminum-Steel Blanks

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