Effect of heat input on cracking in laser solid formed DZ4125 superalloy

Hu, Yunlong; Lin, Xin; Song, Ke; Jiang, Xianhong; Yang, Haiou; Huang, Weidong

doi:10.1016/j.optlastec.2016.06.008

Cited by 49 publications

(12 citation statements)

References 27 publications

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“…It means that the microsegregation of Al + Ti is also a common problem when fabricating Ni-based superalloys with high Al and Ti content by LSF and this conclusion is also supported by many references. 12,14,17,21 In this article, although Rene 104 superalloy was chosen as the experimental material, the effect of preheating and controlled cooling on crack defects can be attributed to the following three aspects: (1) reduction of temperature gradient in deposition direction due to the high preheating temperature, (2) a more equilibrium cooling process and a more uniform temperature field resulted from the slow cooling strategy, and (3) low hardness caused by the long high temperature state. Reduction of temperature gradient, more uniform temperature field, and low hardness of deposited part decrease the thermal stress in the LSF process.…”

Section: Resultsmentioning

confidence: 99%

Effects of preheating and cooling on the crack defects of laser solid formed Rene 104 superalloy parts

Ying

Han

Wang

2020

Proceedings of the Institution of Mechanical Engineers, Part B:

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In this study, laser solid forming technology has been used to fabricate Rene 104 nickel-based superalloy parts, and severe crack problems were found during the laser solid forming process. To solve the crack problems, the effects of preheating and cooling on the microstructure and crack defects of the laser solid forming Rene 104 superalloy were experimentally investigated. The experimental results demonstrated that crack intensity in parts obtained using laser solid forming decreased with the increase in the preheating temperature. However, when the cooling process was not controlled, the parts obtained using laser solid forming would still exhibit severe crack problems even if the preheating temperature was increased to 750 °C. Therefore, instead of natural cooling, a slow cooling strategy was used after the laser solid forming process in the experiments. It was proved that decreasing the cooling rate of the substrate also helped in eliminating the cracks. Using the slow cooling strategy, crack-free Rene 104 superalloy parts could be fabricated at a relatively low preheating temperature. Moreover, it was found that the multiple growth direction of columnar dendrites under high preheating temperature restricted the propagation of cracks. The microsegregation of Al and Ti in the interdendritic regions decreased when the slow cooling strategy was used, leading to improvements in ductility. Aside from the evolution of the microstructure, the relief of thermal stress during the slow cooling process was another important reason for eliminating the cracks.

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Section: Resultsmentioning

confidence: 99%

Effects of preheating and cooling on the crack defects of laser solid formed Rene 104 superalloy parts

Ying

Han

Wang

2020

Proceedings of the Institution of Mechanical Engineers, Part B:

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“…Based on Hu's studies [12], the liquation cracks occurred in LSFed DZ4125 superalloy sample with the lower heat input. However, when the contents of Al and Ti elements reach a certain level, the crack sensitivity cannot be completely eliminated [8].…”

Section: Introductionmentioning

confidence: 98%

“…K465 superalloy parts are mainly formed by conventional casting, leading to some disadvantages in forming efficiency and mechanical properties. Laser metal deposition shaping (LMDS) is an efficient way for producing components with near-net-shaped, directional solidification, and controlled porosity or chemical composition gradient [2,3], and it also knows direct laser fabrication (DLF), or laser solid form (LSF [12], and CM247LC [13] were prone to cracking. The crack sensitivity of nickel-based superalloy increases with the increasing of aluminum and titanium elements.…”

Section: Introductionmentioning

confidence: 99%

“…Laser metal deposition shaping (LMDS) is an efficient way for producing components with near-net-shaped, directional solidification, and controlled porosity or chemical composition gradient [2,3], and it also knows direct laser fabrication (DLF), or laser solid form (LSF). Many LMDS nickel-based superalloys have been reported, such as Inconel 625 [4], Inconel 718 [5,6], Colmonoy 227-F [7], Rene 80 [8], IN 100 [9] et al; nevertheless, some of them (e.g., Inconel 718 [6], Rene104 [10], IN100 [9], K465 [11], DZ4125 [12], and CM247LC [13] were prone to cracking. The crack sensitivity of nickel-based superalloy increases with the increasing of aluminum and titanium elements.…”

Section: Introductionmentioning

confidence: 99%

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Microstructure and Microhardness of Laser Metal Deposition Shaping K465/Stellite-6 Laminated Material

Wang

Zhao

et al. 2017

Metals

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K465 superalloy with high titanium and aluminum contents was easy to crack during laser metal deposition. In this study, the crack-free sample of K465/Stellite-6 laminated material was formed by laser metal deposition shaping to control the cracking behaviour in laser metal deposition of K465 superalloy. The microstructure differences between the K465 superalloy with cracking and the laminated material were discussed. The microstructure and intermetallic phases were analyzed through scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The results showed that the microstructure of K465/Stellite-6 laminated material samples consisted of continuous dendrites with a similar structure size in different alloy deposition layers, and the second dendrite arm spacing was finer compared with laser metal deposition shaping K465. The intermetallic phases in the different alloy deposition layers varied, and the volume fraction of carbides in K465 deposition layer of the laminated material was higher than only K465 deposition under the fluid flow effect. In addition, the composition and microhardness distribution of laminated materials variation occurred along the deposition direction.Keywords: laser metal deposition shaping; laminated material; microstructure; microhardness BackgroundK465 superalloy, known as a nickel-based alloy, is widely used for gas turbine blades and vanes [1]. K465 superalloy parts are mainly formed by conventional casting, leading to some disadvantages in forming efficiency and mechanical properties. Laser metal deposition shaping (LMDS) is an efficient way for producing components with near-net-shaped, directional solidification, and controlled porosity or chemical composition gradient [2,3], and it also knows direct laser fabrication (DLF), or laser solid form (LSF [12], and CM247LC [13] were prone to cracking. The crack sensitivity of nickel-based superalloy increases with the increasing of aluminum and titanium elements. As a result, the research focus of LMDS K465 superalloy concentrates on controlling the cracks. Based on previous studies, the crack category of laser deposition superalloy may contain solidification cracking, grain boundary liquation cracking and ductility dip cracking [10]. Among them, the liquation cracks are the most serious in nickel-based superalloy with a high content of (Al + Ti), and may originate from the liquation of low melting point eutectic in the previous build layers. Chen et al. [6] have found that liquation cracking in laser deposited 718 alloy was on account of

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“…Por outro lado, a fragilização a quente pode ocorrer para determinados parâmetros de deposição. Dessa forma, o calor aportado deve ser controlado para evitar a formação de trincas [16]. Na deposição de cordões de Inconel 625 sob placas de aço inoxidável foi constatada uma baixa diluição do Fe, como 4,5% de Fe, garantindo uma resistencia à corrosão quase tão boa quando a liga fornecida como forjada [14].…”

Section: Introductionunclassified

Soldagem De Revestimento a Laser Em Tubo De Aisi 4130 Empregando Pó De Inconel 625

Gomes¹,

Fontes²,

Rezende³

et al. 2019

ABM Proceedings

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Effect of heat input on cracking in laser solid formed DZ4125 superalloy

Cited by 49 publications

References 27 publications

Effects of preheating and cooling on the crack defects of laser solid formed Rene 104 superalloy parts

Effects of preheating and cooling on the crack defects of laser solid formed Rene 104 superalloy parts

Microstructure and Microhardness of Laser Metal Deposition Shaping K465/Stellite-6 Laminated Material

Soldagem De Revestimento a Laser Em Tubo De Aisi 4130 Empregando Pó De Inconel 625

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