scholarly journals Analysis of the Part Distortions for Inconel 718 SLM: A Case Study on the NIST Test Artifact

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5087
Author(s):  
Silvia Martínez ◽  
Naiara Ortega ◽  
Diego Celentano ◽  
Antonio J. Sánchez Egea ◽  
Eneko Ukar ◽  
...  
Keyword(s):  
Inconel 718 ◽  
Thermal Gradient ◽  
Thermal Stresses ◽  
Weight Ratio ◽  
Coordinate Measuring Machine ◽  
High Strength ◽  
Inconel 718 Alloy ◽  
Geometrical Distortion ◽  
Measurement Protocol ◽  
Measuring Machine

The present paper evaluates the misalignment and geometry distortion of the standard National Institute of Standards and Technology (NIST) test artifact in Inconel 718 alloy, when several layers with and without supports are employed to manufacture it by the Selective Laser Melting (SLM) process. To this end, a coordinate-measuring machine (CMM) is used to measure the geometrical distortion in each manufacturing configuration, following the same measurement protocol. The results show that the laser path strategy favors a thermal gradient which, consequently, induces geometrical distortions in the part. To prove this hypothesis, a numerical simulation is performed to determine the thermal gradient and the pattern of the residual stresses. It was found that the geometrical distortion certainly depends on the position of the feature position and laser strategy, where thermal cycles and residual thermal stresses had an impact in the end-part geometry, especially if a high strength-to-weight ratio commonly used in aeronautics is present.

Microstructure and Tensile Properties of SLM Graphene Reinforced Inconel 718 Alloy After Post Heat Treatment

2018 ◽  
Author(s):  
Yachao Wang ◽  
Jing Shi
Keyword(s):  
Heat Treatment ◽  
Inconel 718 ◽  
Metal Matrix ◽  
High Strength ◽  
Solution Temperature ◽  
Strengthening Effect ◽  
Post Heat Treatment ◽  
Inconel 718 Alloy ◽  
Dense Microstructure ◽  
High Flexibility

Graphene is an ideal reinforcement material for metal matrix composites (MMC) owing to its high strength, high ductility, light weight, as well as good bonding with metal matrix. Additive manufacturing such as selective laser melting (SLM) brings the advantages of low material waste, high flexibility, and short production lead cycle. In this study, graphene nano-platelets (GNPs) reinforced Inconel 718 composites are fabricated by SLM technique and processed under various post heat treatment schemes. It is found that fabrication of GNPs reinforced MMC using SLM technique is a viable approach. The obtained composite possesses dense microstructure and enhanced tensile strength. Post heat treatments at two levels of solution temperature (980 and 1220°C) for 1 hour followed by two-step aging are carried out. The experiment results indicate that addition of GNPs into Inconel 718 matrix results in significant strength improvement. At as-built condition, the ultimate tensile strengths are 997 and 1447 MPa, respectively at 0 and 4.4vol.% GNP content. Moreover, under as-built and solution treated condition, high content of GNPs results in overall higher UTS value and the strengthening effect is most significant at as-built condition. Meanwhile, γ′ and γ″ precipitation hardening is suppressed in the GNPs reinforced composite under aged condition due to the formation of MC carbide and depletion of Nb. Incorporating GNPs in Inconel 718 effectively inhibits the grain growth during post heat treatment.

Evaluation of the Performance of Inconel 718 Fasteners Subjected to Cathodic Protection Systems in Offshore and Subsea Applications

2011 ◽  
Author(s):  
Fabio Pires ◽  
Richard Clements ◽  
Fabio Santos ◽  
Judimar Clevelario ◽  
Terry Sheldrake
Keyword(s):  
Mechanical Properties ◽  
Cathodic Protection ◽  
Inconel 718 ◽  
Nickel Alloys ◽  
High Strength ◽  
Maximum Hardness ◽  
Inconel 718 Alloy ◽  
Protection Systems ◽  
Impressed Current ◽  
Current Systems

Fasteners manufactured with Inconel 718 alloy are being widely used in offshore and subsea applications due to the material’s high strength, when compared to other nickel alloys, and its inherent corrosion resistance. However, concerns have been raised over its utilization in applications where cathodic protection or impressed current systems are in place. These concerns relate to the susceptibility to hydrogen embrittlement that Inconel 718 alloy may present depending on its processing, microstructure, hardness and actuating stresses. Over the last few years, much has been discussed on the suitability of the alloy for subsea applications. The development of special thermal cycles for the ageing of the alloy has been necessary to provide a consistent material with a maximum hardness of 35 HRc, and a microstructure free of detrimental phases without jeopardizing the overall mechanical properties of the alloy. Wellstream has developed a test programme focused on the assessment of Inconel 718 behavior when subjected to cathodic protection systems. Through this programme, it was possible to demonstrate the suitability of Inconel 718 alloy in subsea applications when the resulting microstructure and hardness are properly controlled, and bolt loading is within normal working limits.

scholarly journals The Precipitation Processes and Mechanical Properties of Aged Inconel 718 Alloy After Annealing

2017 ◽  
Vol 62 (3) ◽  
pp. 1695-1702 ◽  
Author(s):  
P. Maj ◽  
B. Adamczyk-Cieslak ◽  
M. Slesik ◽  
J. Mizera ◽  
T. Pieja ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Inconel 718 ◽  
Aging Process ◽  
High Strength ◽  
Inconel 718 Alloy ◽  
Transmission Microscopy ◽  
Nickel Iron ◽  
Temperature Range ◽  
Hardness Tests ◽  
Strength And Ductility

AbstractInconel 718 is a precipitation hardenable nickel-iron based superalloy. It has exceptionally high strength and ductility compared to other metallic materials. This is due to intense precipitation of the γ’ and γ” strengthening phases in the temperature range 650-850°C. The main purpose of the authors was to analyze the aging process in Inconel 718 obtained in accordance with AMS 5596, and its effect on the mechanical properties. Tensile and hardness tests were used to evaluate the mechanical properties, in the initial aging process and after reheating, as a function of temperature and time respectively in the ranges 650°-900°C and 5-480 min. In addition, to link the mechanical properties with the microstructure transmission microscopy observations were carried out in selected specimens. As a result, factors influencing the microstructure changes at various stages of strengthening were observed. The authors found that the γ’’ phase nucleates mostly homogenously in the temperature range 650-750°C, causing the greatest increase in strength. On the other hand, the γ’ and δ phases are formed heterogeneously at 850°C or after longer annealing in 800°C, which may weaken the material.

Research on Mechanical Properties of Thin Sheets Blanks Made of Creep-Resisting Nickel Superalloys

2013 ◽  
Vol 212 ◽  
pp. 259-262
Author(s):  
Monika Hyrcza-Michalska
Keyword(s):  
Mechanical Properties ◽  
Inconel 718 ◽  
Nickel Alloys ◽  
Thin Sheet ◽  
High Strength ◽  
Inconel 625 ◽  
Thin Sheets ◽  
Inconel 718 Alloy ◽  
Mechanical Working ◽  
Inconel Alloys

Mechanical working manufacturing methods of nickel alloys used conventionally strips and blanks need to solve many problems concerning high strength material forming which is characteristic limited plasticity. The production pressed elements of vehicle constructions and aircraft engine elements requires the high quality drawpieces since these are essential for safety. They are also the main structural components. Conventional methods of mechanical working such as pressing can be used in quantity production of the above mentioned elements and their production can also be cost-effective. Forming nickel alloys generates a lot of technological wastes resulting from back-springing effects determining the most appropriate pressure in the process of pressing. Failure holes in the process of bulging as well as cracking of drawpieces in the process of deep drawing. The heterogeneous mechanical properties distribution on thin sheet blanks made of Inconel alloy, which is different than material quality certificate shows, produces also a lot of manufacturing problems. These problems are usually solved by production engineers in the following way: dividing the production of ready drawpieces into a bigger number of simple blank profiling operations, shallow pressing, using a rubber punch for pressing or hydroforming. Complex drawpieces shapes are quite often made of several parts which are next welded. In the case of presented tube a tubular diffuser made of Inconel 718 alloy blank and cone made of Inconel 625. However the process of forming high strength materials like nickel alloys requires the application bigger forming forces than in the same kind of conventional formable steel processes. Tools get jammed quite often in the process and high force presses of 10 MN or more need to be used so is very expensive. The aspect of cold mechanical forming discussed materials has been a particular interest. The researches based on precise evaluation mechanical properties and technological plasticity of the selected materials in basic mechanical and technological tests as well as in FEM numerical simulation (finite elements method). The material models applied to simulation contain the pointed out experimentally the mechanical characteristics of Inconel alloys. The thin sheets blanks made of 0,9 mm thick Inconel 718 alloy and 0,45 mm thick Inconel 625 alloy blanks have been examined. The possibilities of using numerical simulations for solving the problems of selecting or modifying the pressing technology and hydroforming that type materials as well as forecasting the results of forming processes have been also presented. The evaluation of drawability of thin sheets blanks made of Inconel 718 and 625 alloys has also been discussed in the paper.

scholarly journals Uncertainty assessment for measurement and simulation in selective laser melting: a case study of an aerospace part

ACTA IMEKO ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 96
Author(s):  
Giulio D'Emilia ◽  
Antoniomaria Di Ilio ◽  
Antonella Gaspari ◽  
Emanuela Natale ◽  
Antonios G. Stamopoulos
Keyword(s):  
Additive Manufacturing ◽  
Selective Laser Melting ◽  
Manufacturing Process ◽  
Thermal Stresses ◽  
Hybrid Approach ◽  
Coordinate Measuring Machine ◽  
Thermal Treatments ◽  
Laser Melting ◽  
Measuring Machine ◽  
Simulation Results

<p class="Abstract"><span lang="EN-US">In this work, the additive manufacturing process selective laser melting is analysed with the aim of realising a complex piece for aerospace applications. In particular, the effect of the manufacturing process and of the following thermal treatments on the dimensions of the workpiece is evaluated. The study is based on a hybrid approach including a simulation of the whole manufacturing process by advanced software packages and the dimensional measurements of the realised pieces taken by a coordinate measuring machine (CMM). The integrated use of simulation and measurements is carried out with the aim of validating the simulation results and of identifying the operational limits of both approaches; this analysis is based on metrological evaluation of the results of both the simulation and the tests, taking into account the uncertainty of the data. In addition, the main causes of uncertainty for the simulation activity and the experimental data have been identified, and the effects of some of them have also been experimentally evaluated. Based on the experimental validation, the simulation seems to predict the absolute displacement of the supports of the piece in a satisfactory way, while it is unable, in the actual configuration, to assess the conformity of the surface to its very tight shape tolerances. Conformity assessment of the surface should be carried out by CMM measurement. Integrated use of simulation and experimental results is expected to strongly improve the accuracy of simulation results for the effective and accurate design and control of the additive manufacturing process, including dimensional control and thermal treatments to mitigate induced thermal stresses.</span></p>

The Addition of Zr in Nickel-Based Inconel 718 Superalloy to Prevent Hot Cracks Propagation

2017 ◽  
Vol 727 ◽  
pp. 3-8 ◽  
Author(s):  
Heng Zhao ◽  
Qing Bin Liu ◽  
Gang Lee ◽  
Da Wei Yao
Keyword(s):  
Inconel 718 ◽  
High Strength ◽  
Inconel 718 Alloy ◽  
High Productivity ◽  
Size Refinement ◽  
Time Control ◽  
Inconel 718 Superalloy ◽  
Cracks Propagation ◽  
Strength And Ductility

The Inconel 718 alloy owes high strength and ductility at high temperature due to precipitation strengthening. In order to upgrade productility of Inconel 718 alloy, the Inconel 718 alloy solve hot crackings through Zr additions. The result shows that, the Inconel 718 alloy with Zr addition achieves grain size refinement and homogenization effect. It is suggested that, homogenization process, such as temperature point and time control, realizes low content of Nb segregation which is the key to prevent hot crackings. At the same time, through dendrite space measurement, the grain refinement realize high productivity of forged Inconel 718 alloy, as a another method of soft effect. In conclusion, adding Zr element is one of dominant methods for producing high quality of Inconel 718 alloy.

Microstructure and Tensile Performance of Graphene-Reinforced Inconel 718 Alloy Via Selective Laser Melting and Post-Treatments

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Yachao Wang ◽  
Jing Shi
Keyword(s):  
Selective Laser Melting ◽  
Inconel 718 ◽  
Metal Matrix ◽  
Load Transfer ◽  
High Strength ◽  
Solution Temperature ◽  
Strengthening Effect ◽  
Laser Melting ◽  
Inconel 718 Alloy ◽  
Dense Microstructure

Abstract Graphene is an ideal reinforcement material for metal matrix composites (MMCs) owing to its high strength, high ductility, light weight, as well as good bonding with metal matrix. In this study, graphene nanoplatelets (GNPs) reinforced Inconel 718 composites are fabricated by selective laser melting (SLM) technique and processed under various postheat treatment schemes. It is found that the fabrication of GNPs-reinforced MMC using the SLM technique is a viable approach. The obtained composite possesses dense microstructure and enhanced tensile strength. Postheat treatments at two levels of solution temperature (980 and 1220 °C) for 1 h followed by two-step aging are carried out. The experimental results indicate that the addition of GNPs into Inconel 718 matrix results in significant strength improvement. Under the as-built condition, the ultimate tensile strengths (UTSs) of SLM Inconel 718 materials are 997 and 1447 MPa, respectively, at 0 and 4.4 vol % GNP content. The strengthening effect of GNPs is most prominent under the as-built condition, and the strength of as-built GNPs-reinforced Inconel 718 is higher than that of unreinforced Inconel 718 under any processing conditions. The formation of γ′ and γ″ precipitates is suppressed in the GNPs-reinforced composite under the aging condition due to the formation of metallic carbide (MC) carbide and the depletion of Nb. GNPs effectively inhibits grain growth during postheat treatment. Quantitative investigation of the various strengthening effects demonstrates that load transfer effect is dominating among all contributors.

Characterization of Additive Manufactured Inconel 718 Alloy Using Laser Cladding

2021 ◽  
Vol 882 ◽  
pp. 3-10
Author(s):  
Prayag Burad ◽  
G. Chaitanya ◽  
Nikhil Thawari ◽  
Jatin Bhatt ◽  
T.V.K. Gupta
Keyword(s):  
Laser Cladding ◽  
Inconel 718 ◽  
Elevated Temperatures ◽  
High Strength ◽  
Inconel 718 Alloy ◽  
Powder Morphology ◽  
Material Deposition ◽  
Layer Deposition ◽  
Engine Components

Laser based metal additive manufacturing (AM) is an emerging technology in various aerospace industries including aero-engine components and turbine manufactures. Laser cladding is a potential process for material deposition and surface enhancement technique that forms a strong metallurgical bond with the substrate. In the present study, Nickel based Inconel 718 (IN718) super alloy which maintains high strength working at elevated temperatures is used as the clad material. The study investigates the processing of Inconel 718 with powder morphology and microstructural properties and also two, three and four-layer deposition. This study explores the possibility of depositing IN718 using laser cladding that can be better considered as metal AM process.

The Nature of Delta Phase Precipitation in Inconel 718

1982 ◽  
Vol 40 ◽  
pp. 724-725
Author(s):  
L. S. Lin ◽  
C. C. Law
Keyword(s):  
Inconel 718 ◽  
Base Alloy ◽  
High Strength ◽  
Physical Metallurgy ◽  
Nickel Base Alloy ◽  
Phase Precipitation ◽  
Weight Percentage ◽  
Delta Phase ◽  
The Subject ◽  
Nickel Base

Inconel 718, a precipitation hardenable nickel-base alloy, is a versatile high strength, weldable wrought alloy that is used in the gas turbine industry for components operated at temperatures up to about 1300°F. The nominal chemical composition is 0.6A1-0.9Ti-19.OCr-18.0Fe-3Mo-5.2(Cb + Ta)- 0.1C with the balance Ni (in weight percentage). The physical metallurgy of IN 718 has been the subject of a number of investigations and it is now established that hardening is due, primarily, to the formation of metastable, disc-shaped γ" an ordered body-centered tetragonal structure (DO2 2 type superlattice).

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