Hot-cracks reduction during Laser Beam Welding in vacuum of conventionally cast Alloy-247 LC

Senger, Aleksej; Jokisch, Torsten; Olschok, Simon; Reisgen, Uwe; Fischer, Thomas M.

doi:10.1016/j.procir.2020.09.097

Cited by 4 publications

(3 citation statements)

References 7 publications

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“…[27]. These conditions represent an unexplored conditional combination between heat input and high-energy density, while recent previously mentioned studies approximately covered heat inputs from 25 to 220 J/mm and energy densities from 30 to 280 J/mm 2 [5,[15][16][17][18][19][20][21][22]. For the circular wobble welding, three levels of wobble frequency (10,15,20 kHz) were applied at each scan speed with 0.1 mm of wobble amplitude.…”

Section: Single-mode Fibre Laser Weldingmentioning

confidence: 99%

“…Welding and joining are essential processes in blade manufacturing, and the soundness of the joint is directly related to the durability of the blade. However, the 247LC superalloy, which is known to be a difficult material to weld, suffers from hot weld cracking phenomena including solidification, liquation, and ductility-dip cracks [3][4][5][6]. These are also present in additive manufacturing processes [7][8][9][10].…”

Section: Introductionmentioning

confidence: 99%

“…Consequently, suppression of the diffusion-controlled liquation reaction can be considered an effective solution for the liquation crackfree welding of the difficult-to-weld 247LC superalloy. In this regard, applicability of laser welding technologies has been examined for 247LC [5] and other precipitation-hardened superalloys, which suffer from liquation cracking. These include Rene80 [14], Haynes282 [15], IN738LC [16], GH909 [17], GTD111 [18][19][20], IC10 [21], and K447A [22].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Liquation crack-free welding strategy for 247LC DS superalloy by control of pipeline diffusion via ultra-high-speed laser beam scanning

Chun

Jeong

Kim

et al. 2023

Science and Technology of Welding and Joining

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Under completely suppressed constitutional liquation of MC carbide, unexplored 247LC superalloy single-mode fibre laser welds experience unexpected liquation cracking. These cracks continuously propagate from a solidification crack, particularly at highly misoriented and epitaxially grown solidification grain boundaries, and dominated by pipeline diffusion of impurities. Two novel metallurgical preconditions were identified which, if satisfied, ensure complete suppression of liquation cracking of 247LC superalloy welds. These preconditions are (i) the constitutional liquation of MC carbide at the heat-affected zone and (ii) pipeline diffusion of impurities at the fusion zone. It is also highly recommended that the welding is carried out in a single directionally solidified grain under scanning conditions, avoiding the formation of highly misoriented solidification grain boundaries.

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Section: Single-mode Fibre Laser Weldingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Liquation crack-free welding strategy for 247LC DS superalloy by control of pipeline diffusion via ultra-high-speed laser beam scanning

Chun

Jeong

Kim

et al. 2023

Science and Technology of Welding and Joining

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A review on welding techniques: properties, characterisations and engineering applications

Shravan

Radhika

Kumar

et al. 2023

Advances in Materials and Processing Technologies

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Method of Suppressing Solidification Cracking by Laser Surface Melting and Epitaxial Growth Behavior for Directionally Solidified 247LC Superalloy

Kim¹,

Chun²

2023

Korean J. Met. Mater.

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In this study, the relationship between solidification cracking and epitaxial growth behavior with the high-speed laser surface melting of a directionally solidified 247LC superalloys was fundamentally and metallurgically investigated, to develop a successful welding procedure for the next generation of gas turbine blades. Under typical laser surface melting conditions (scan speed: 50 mm/s, heat input: 40 J/mm), severe solidification cracking phenomena occurs. The key metallurgical factors of solidification cracking have been identified as solidification segregation-assisted pipeline diffusion behavior at the solidification grain boundary, and in the randomly formed polycrystalline melting zone microstructure. In addition, under extremely low heat input and high-speed laser beam scan conditions (scan speed: 1000 mm/s, heat input: 2 J/mm), an effective surface melting zone can be obtained within a single directionally solidified grain under a relatively high-energy beam density (65 J/mm<sup>2</sup>) using the characteristics of single-mode fiber lasers. Results reveal that the laser melting zone successfully shows a 99.9% epitaxial growth achievement ratio. Because of the superior epitaxial growth ratio within the laser surface melting zone, and the rapid solidification phenomena, formation of a solidification grain boundary and solidification segregation-assisted pipeline diffusion behavior can be suppressed. Finally, a solidification crack-free laser melting zone can thus be achieved.

show abstract

Hot-cracks reduction during Laser Beam Welding in vacuum of conventionally cast Alloy-247 LC

Cited by 4 publications

References 7 publications

Liquation crack-free welding strategy for 247LC DS superalloy by control of pipeline diffusion via ultra-high-speed laser beam scanning

Liquation crack-free welding strategy for 247LC DS superalloy by control of pipeline diffusion via ultra-high-speed laser beam scanning

A review on welding techniques: properties, characterisations and engineering applications

Method of Suppressing Solidification Cracking by Laser Surface Melting and Epitaxial Growth Behavior for Directionally Solidified 247LC Superalloy

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