Microstructural Development of Inconel 625 Nickel-based Superalloy as Function of Laser Powder Bed Fusion Parameters PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Microstructural Development of Inconel 625 Nickel-based Superalloy as Function of Laser Powder Bed Fusion Parameters PDF full book. Access full book title Microstructural Development of Inconel 625 Nickel-based Superalloy as Function of Laser Powder Bed Fusion Parameters by Sofia Carolina Nucci. Download full books in PDF and EPUB format.
Author: Sofia Carolina Nucci
Publisher:
ISBN:
Category :
Languages : en
Pages : 46
Get Book Here
Book Description
Additive manufacturing (AM) allows fabrication of complex components with features that are impractical or impossible to achieve through conventional methods. Selective laser melting (SLM) powder bed fusion AM technology was selected for this study on Inconel 625, a widely utilized high-temperature alloy that is hard to machine. The present work investigates impact of laser power and scanning speed variations on the resulting characteristics of fabricated IN625 samples. Gas atomized metallic alloy powders were acquired and analyzed through laser diffraction to verify acceptable size distribution. Cubic samples were built with a range of laser scan speeds in 200 mm/s intervals for each laser power evaluated (125W, 200W, 275W, and 350W) while holding a constant 0.12 mm hatch spacing, 0.03 mm layer thickness, and 16-degree scan rotation angle. Archimedes’ method and optical image analysis were carried out to determine relative density of the samples. All laser powers evaluated yielded at least one sample with relative density above 99.7% as determined through both measurement techniques. Correlation of energy density with resulting sample porosity was identified with highest relative density values associated to energy densities in the 55 – 69 J/mm3 range. Samples were sectioned and etched for examination of relevant microstructural features through optical and scanning electron microscopy; melt pools were measured and cell size approximated. Consistent cooling rate values in the order of 105 – 106 K/s were obtained from Rosenthal’s equation models and from secondary dendrite arm spacing calculation.
Author: Sofia Carolina Nucci
Publisher:
ISBN:
Category :
Languages : en
Pages : 46
Get Book Here
Book Description
Additive manufacturing (AM) allows fabrication of complex components with features that are impractical or impossible to achieve through conventional methods. Selective laser melting (SLM) powder bed fusion AM technology was selected for this study on Inconel 625, a widely utilized high-temperature alloy that is hard to machine. The present work investigates impact of laser power and scanning speed variations on the resulting characteristics of fabricated IN625 samples. Gas atomized metallic alloy powders were acquired and analyzed through laser diffraction to verify acceptable size distribution. Cubic samples were built with a range of laser scan speeds in 200 mm/s intervals for each laser power evaluated (125W, 200W, 275W, and 350W) while holding a constant 0.12 mm hatch spacing, 0.03 mm layer thickness, and 16-degree scan rotation angle. Archimedes’ method and optical image analysis were carried out to determine relative density of the samples. All laser powers evaluated yielded at least one sample with relative density above 99.7% as determined through both measurement techniques. Correlation of energy density with resulting sample porosity was identified with highest relative density values associated to energy densities in the 55 – 69 J/mm3 range. Samples were sectioned and etched for examination of relevant microstructural features through optical and scanning electron microscopy; melt pools were measured and cell size approximated. Consistent cooling rate values in the order of 105 – 106 K/s were obtained from Rosenthal’s equation models and from secondary dendrite arm spacing calculation.
Author: Jinghao Xu
Publisher: Linköping University Electronic Press
ISBN: 9179297269
Category :
Languages : en
Pages : 63
Get Book Here
Book Description
Nickel-based superalloys, an alloy system bases on nickel as the matrix element with the addition of up to 10 more alloying elements including chromium, aluminum, cobalt, tungsten, molybdenum, titanium, and so on. Through the development and improvement of nickel-based superalloys in the past century, they are well proved to show excellent performance at the elevated service temperature. Owing to the combination of extraordinary high-temperature mechanical properties, such as monotonic and cyclic deformation resistance, fatigue crack propagation resistance; and high-temperature chemical properties, such as corrosion and oxidation resistance, phase stability, nickel-based superalloys are widely used in the critical hot-section components in aerospace and energy generation industries. The success of nickel-based superalloy systems attributes to both the well-tailored microstructures with the assistance of carefully doped alloying elements, and the intently developed manufacturing processes. The microstructure of the modern nickel-based superalloys consists of a two-phase configuration: the intermetallic precipitates (Ni,Co)3(Al,Ti,Ta) known as γ′ phase dispersed into the austenite γ matrix, which is firstly introduced in the 1940s. The recently developed additive manufacturing (AM) techniques, acting as the disruptive manufacturing process, offers a new avenue for producing the nickel-based superalloy components with complicated geometries. However, γ′ strengthened nickel-based superalloys always suffer from the micro-cracking during the AM process, which is barely eliminated by the process optimization. On this basis, the new compositions of γ′ strengthened nickel-based superalloy adapted to the AM process are of great interest and significance. This study sought to design novel γ′ strengthened nickel-based superalloys readily for AM process with limited cracking susceptibility, based on the understanding of the cracking mechanisms. A two-parameter model is developed to predict the additive manufacturability for any given composition of a nickel-based superalloy. One materials index is derived from the comparison of the deformation-resistant capacity between dendritic and interdendritic regions, while another index is derived from the difference of heat resistant capacity of these two spaces. By plotting the additive manufacturability diagram, the superalloys family can be categorized into the easy-to-weld, fairly-weldable, and non-weldable regime with the good agreement of the existed knowledge. To design a novel superalloy, a Cr-Co-Mo-W-Al-Ti-Ta-Nb-Fe-Ni alloy family is proposed containing 921,600 composition recipes in total. Through the examination of additive manufacturability, undesired phase formation propensity, and the precipitation fraction, one composition of superalloy, MAD542, out of the 921,600 candidates is selected. Validation of additive manufacturability of MAD542 is carried out by laser powder bed fusion (LPBF). By optimizing the LPBF process parameters, the crack-free MAD542 part is achieved. In addition, the MAD542 superalloy shows great resistance to the post-processing treatment-induced cracking. During the post-processing treatment, extensive annealing twins are promoted to achieve the recrystallization microstructure, ensuring the rapid reduction of stored energy. After ageing treatment, up to 60-65% volume fraction of γ′ precipitates are developed, indicating the huge potential of γ′ formation. Examined by the high-temperature slow strain rate tensile and constant loading creep testing, the MAD542 superalloy shows superior strength than the LPBF processed and hot isostatic pressed plus heat-treated IN738LC superalloy. While the low ductility of MAD542 is existed, which is expected to be improved by modifying the post-processing treatment scenarios and by the adjusting building direction in the following stages of the Ph.D. research. MAD542 superalloy so far shows both good additive manufacturability and mechanical potentials. Additionally, the results in this study will contribute to a novel paradigm for alloy design and encourage more γ′-strengthened nickel-based superalloys tailored for AM processes in the future.
Author: Erica Jordan Drobner
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Get Book Here
Book Description
Author: Flake C. Campbell
Publisher: ASM International
ISBN: 1615030581
Category : Technology & Engineering
Languages : en
Pages : 671
Get Book Here
Book Description
This practical reference provides thorough and systematic coverage on both basic metallurgy and the practical engineering aspects of metallic material selection and application.
Author: Joseph R. Davis
Publisher: ASM International
ISBN: 0871706857
Category : Technology & Engineering
Languages : en
Pages : 450
Get Book Here
Book Description
This book is a comprehensive guide to the compositions, properties, processing, performance, and applications of nickel, cobalt, and their alloys. It includes all of the essential information contained in the ASM Handbook series, as well as new or updated coverage in many areas in the nickel, cobalt, and related industries.
Author: Kewin Gola
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Get Book Here
Book Description
Author: John C. Lippold
Publisher: John Wiley & Sons
ISBN: 1118210034
Category : Technology & Engineering
Languages : en
Pages : 370
Get Book Here
Book Description
The most up-to-date coverage of welding metallurgy aspects and weldability issues associated with Ni-base alloys Welding Metallurgy and Weldability of Nickel-Base Alloys describes the fundamental metallurgical principles that control the microstructure and properties of welded Ni-base alloys. It serves as a practical how-to guide that enables engineers to select the proper alloys, filler metals, heat treatments, and welding conditions to ensure that failures are avoided during fabrication and service. Chapter coverage includes: Alloying additions, phase diagrams, and phase stability Solid-solution strengthened Ni-base alloys Precipitation strengthened Ni-base alloys Oxide dispersion strengthened alloys and nickel aluminides Repair welding of Ni-base alloys Dissimilar welding Weldability testing High-chromium alloys used in nuclear power applications With its excellent balance between the fundamentals and practical problem solving, the book serves as an ideal reference for scientists, engineers, and technicians, as well as a textbook for undergraduate and graduate courses in welding metallurgy.
Author: Christopher U. Brown
Publisher:
ISBN:
Category : Additives
Languages : en
Pages : 57
Get Book Here
Book Description
The goal of this study was to investigate the relationship between mechanical and material properties (including density) of manufactured nickel super alloy (IN625) using a laser powder bed fusion process and three process parameters: laser power, hatch distance, and scan speed. Hardness of the manufactured blocks was measured as a representative of the mechanical properties. Density measurements were carried out using the pyncometry method. Three sets of blocks were manufactured using IN625 metal powder (nitrogen gas atomized) on a laser powder bed fusion machine. Different combinations of process parameters yielded different energy densities for each block for the three builds. The laser scan speed, laser power, hatch distance, and energy density all had statistically significant relationships with hardness. The average bulk density increased non-linearly with increasing values of energy density. A similar trend was in the hardness data. The results of this study served as a guide to determine the range of parameters yielding acceptable material properties for the investigation of process parameter sensitivities during a subsequent IN625 round robin study.
Author: Sila Atabay
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
"Laser powder bed fusion (LPBF) is a promising technology that enables production of complex parts with unique freedom in design and short lead times. For applications requiring high strength and high temperature resistance, Ni-base superalloys are the primary choice of materials. Although variety of superalloys can be produced through LPBF, most high strength alloys are prone to cracking and considered difficult to weld. The main objective of this research is to assess the processability of precipitation hardenable Ni-base superalloys by LPBF. For this purpose, processing of two different precipitation hardenable alloys, Rene 41 (R41) having a fair weldability and Rene 77 (R77) categorized as difficult to weld, are studied along with their microstructural development and mechanical properties. First, R41 alloy was produced by LPBF, and its microstructural evolution was investigated. Crack-free, dense samples were produced upon parameter optimization. The as-built (AB) microstructure revealed columnar grains with a preferred orientation along 100 direction. [gamma]' precipitation was suppressed due to high cooling rates in LPBF. Afterwards, the samples were subjected to the standard heat treatment (HT). Even though the grain morphology was similar to the AB sample, formation of carbide particles was observed along with the precipitation of [gamma]' after the HT. Mechanical properties of the samples both in AB and HT state was characterized. Results proved that when standard HT is applied to the LPBF fabricated R41 parts, the measured room temperature (RT) strength and elongation meet the AMS specifications. Effect of build direction on the mechanical properties was also studied. Since the microstructure obtained after LPBF is very different compared to the conventional processing techniques, suitability of the commercially applied HT cycles has to be studied. Hence, additional HTs were applied to understand the effect of different solutionizing temperatures on the development of microstructure and mechanical properties. Detailed microstructural analysis were conducted after each HT. These analyses revealed that for HT above the [gamma]' solvus temperature, resulted in the precipitation of [gamma]' and carbide phases similarly to the sub-solvus HT but with a different size distribution and morphology. However, formation of an equiaxed grain morphology with random orientation was detected. Furthermore, tensile properties were tested at 760°C. YS and UTS values obtained for AB, sub-solvus and super-solvus HT samples were on par with the wrought and HT alloys reported in literature. However, the measured elongation and deformation behaviors showed significant differences. The columnar grain morphology of the sub-solvus HT sample led to the highest elongation while the microstructure obtained after super-solvus treatment had the highest work hardening rate during deformation. Finally, the knowledge gained from R41 was used to study the manufacturability of the R77 alloy. This alloy is more prone to cracking during fabrication due to its higher content of alloying elements. Elimination of cracking in a difficult to weld alloy solely by parameter optimization was proven possible with LPBF of R77. Furthermore, these crack-free structures were maintained upon a modified version of the standard HT. Detailed microstructural characterization of AB and HT samples were conducted similarly to the R41. In this case, presence of extremely fine [gamma]' precipitates were identified after LPBF, and a bimodal distribution of precipitates was developed following the HT. Tensile properties for both conditions were tested at RT and 810 °C and the results were compared with wrought counterparts and with other difficult to weld alloys fabricated by LPBF. The deformation behavior of the samples in both conditions changed with the temperature. AB sample showed significant hardening whereas, the HT one had improved elongation due to thermally activated microtwinning"--
Author: Matthew J. Donachie
Publisher: ASM International
ISBN: 1615030646
Category : Heat resistant alloys
Languages : en
Pages : 439
Get Book Here
Book Description
This book covers virtually all technical aspects related to the selection, processing, use, and analysis of superalloys. The text of this new second edition has been completely revised and expanded with many new figures and tables added. In developing this new edition, the focus has been on providing comprehensive and practical coverage of superalloys technology. Some highlights include the most complete and up-to-date presentation available on alloy melting. Coverage of alloy selection provides many tips and guidelines that the reader can use in identifying an appropriate alloy for a specific application. The relation of properties and microstructure is covered in more detail than in previous books.
