Super Alloys Research Papers - Academia.edu (original) (raw)

The characterization of non-metallic inclusions is of great importance for the production of metals and alloys. The precise determination of their size, abundance, shape and chemistry is of crucial interest to control and to improve production and quality of steel or other alloys. For two years, a combined research team including ERAMET RESEARCH and AUBERT & DUVAL has developed a new characterization method based on automated SEM measurements. This method allows analyzing centimeter-sized samples within a few hours. Each inclusion with a diameter larger than two microns is detected and analyzed. A fast BSE measurement coupled with EDS analyzes, calibrated with a microprobe, enables to establish precisely, for each inclusion, its size, morphology, chemistry and mineral composition. The main advantage of this method, in comparison with the other commercially available applications, is that with increasing inclusion size, the amount of chemical analyses can be increased. It is even possible to determine the compositional variations within large inclusions. In particular, these data are used to plot inclusion compositions on thermodynamically derived phase diagrams. It is also possible to establish the evolution based on variations in inclusion chemistries during a process. This method is efficient, both on samples originating from liquid metal sampling and on forged samples.

- by
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- Cleanliness, Metalurgy, Super Alloys, QEMSCAN

The present work investigates the influence of micro-alloyed Mo on the corrosion behavior of (CoCrFeNi) 100−x Mo x high-entropy alloys. All of the (CoCrFeNi) 100−x Mo x alloys exhibit a single face-centered cubic (FCC) solid solution. However, the (CoCrFeNi) 97 Mo 3 alloy exhibits an ordered sigma (σ) phase enriched in Cr and Mo. With the increase of x (the Mo content) from 1 to 3, the hardness of the (CoCrFeNi) 100−x Mo x alloys increases from 124.8 to 133.6 Vickers hardness (HV), and the compressive yield strength increases from 113.6 MPa to 141.1 MPa, without fracture under about a 60% compressive strain. The potentiodynamic polarization curve in a 3.5% NaCl solution indicates that the addition of Mo has a beneficial effect on the corrosion resistance to some certain extent, opposed to the σ phase. Furthermore, the alloys tend to form a passivation film in the 0.5 M H 2 SO 4 solution in order to inhibit the progress of the corrosion reaction as the Mo content increases.

- by Qing Peng
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- Corrosion Science, Corrosion Engineering, Corrosion, High Entropy Alloys

In this paper we list out root elements as per Vedic Metallurgy described in Vaimanika Prakarana of Bharadwaja . Root or Beeja Loha as they are called are , elements formed inside the earth during formation of earth’s crust & by influence of cosmic rays coming from Sun , Moon & other deep space objects . By using different combinations of these Beeja Lohas , different alloys are made which had advanced properties like heat absorbent, heat resistant , light weight , cold resistant etc

- by Kenan Altınok
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- Mechanical Alloying, Nickel, Edm of Inconel 718, Super Alloys
- by Gabriel Fernandez
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- Super Alloys

Advancements made in the field of materials have contributed in a major way in building gas turbine engines with higher power ratings and efficiency levels. Improvements in design of the gas turbine engines over the years have importantly been due to development of materials with enhanced performance levels. Gas turbines have been widely utilised in power generation, industrial sector, marine sector and as aircraft engines. This article focuses on aero engine applications. Advancements in gas turbine materials have been always a major concern – higher their capability to withstand elevated temperature service and more the engine efficiency; for the materials with high temperature to weight ratio helps in weight reduction. The article reviews the evolutionary process that has taken place over the years with reference to the different groups of materials used for aero engines. The review brings out a description of the material grades currently used, prominently including their superior performance characteristics which led to the designer selecting them. A wide spectrum of high performance materials, whose manufacture often involves advanced processing techniques, is used for construction of gas turbines namely special steels, titanium alloys, super alloys. Other major group of materials like ceramics, composites and inter-metallics are presently under intense research and development towards their implementation in various aero-engine components. The present analysis will go into the superior attributes of these various groups making them the designer’s choice for different components in the aero-engine.
Many of the components in the aero engines are subjected to fatigue- and /or creep-loading, and the choice of material is then based on the capability of the material to withstand such loads. The paper goes into the types of loading experienced by different components and how advanced gas turbine materials are designed and produced to withstand these loads. Coating technology has become an integral part of manufacture of gas turbine engine components operating at high temperatures, as this is the only way a combination of high level of mechanical properties and excellent resistance to oxidation / hot corrosion resistance could be achieved. The review brings out a detailed analysis of the advanced materials and processes that have come to stay in the production of various components in gas turbine engines.

- by Sathyanarayanan S
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- Materials, Hot Corrosion, Inter metals, Super Alloys

As the era develops and the demand of the technology is compulsory, materials that been extracted from inside the earth is not enough to compensate it. Such as alloys, the demand of alloys that is capable to be used in extreme condition and environment is highly inclining nowadays. The usage of superalloys which is based form nickel and cobalt is one of the option for extreme environment. However, these alloys is unable to balance the growing technologies that have been developed due to they have very high weight and heavy in order to increase their strength.

High-entropy alloys (HEAs) have recently become a vibrant field of study in the metallic materials area. In the early years, the design of HEAs was more of an exploratory nature. The selection of compositions was somewhat arbitrary, and there was typically no specific goal to be achieved in the design. Very recently, however, the development of HEAs has gradually entered a different stage. Unlike the early alloys, HEAs developed nowadays are usually designed to meet clear goals, and have carefully chosen components, deliberately introduced multiple phases, and tailored microstructures. These alloys are referred to as advanced HEAs. In this paper, the progress in advanced HEAs is briefly reviewed. The design strategies for these materials are examined and are classified into three categories. Representative works in each category are presented. Finally, important issues and future directions in the development of advanced HEAs are pointed out and discussed.

- by Saminu Inuwa Bala
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- Materials Science, Inter metals, Super Alloys, Temperature Coatings

Computer aided design of runner & gate in die casting Abstract Die Casting is a high tolerance process due to the high Accuracy of Data to reduce the error factor as much as possible the objective of this paper is to design an Aluminum A380 thermo-fan, Aluminum is a low Density ,High Thermal Conductivity & the low Heat in solidification makes the runner design more difficult, computer Solution in Visual Basic is needed to make a Model of the necessary Equations to Calculate

- by Raad S Hafidh
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- Computer Aided Design, Die-casting, Super Alloys

La escasez de estudios in situ sobre procesos de colada
continua horizontal en aleaciones de aluminio,
impulsa la necesidad de investigar la influencia de
temperatura, velocidad y materia prima en billets de
aluminio homogenizados AA6063. Aplicando ensayos
de espectrometría, permiten cuantificar el porcentaje
en peso de aleantes principales magnesio y silicio.
Estos elementos al precipitar forman siliciuro de magnesio
(Mg2Si) durante el proceso de homogenizado.
Para este estudio se produjo billets de aleación normal
y experimental, demostrando una relación inversa
entre los niveles de siliciuro de magnesio y dureza
Brinell; así también la influencia de bajos niveles de
porcentaje en peso de Mg2Si en la reducción de la
resistencia a la tracción en el material.

- by Ingenius: Revista de Ciencia y Tecnología and +1
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- Aluminium Alloys, Extrusion Processing, Super Alloys, Billets

The present research focuses on dry sliding friction and wear behaviour of Nimonic 80A and Nimonic 90 against Nimonic 75 at high temperature up to 1023 K. The influence of temperature, sliding distance and normal load on friction and wear behaviour of Nimonic 80A and Nimonic 90 against Nimonic 75 was studied using pin (Nimonic 75)-on-disc (Nimonic 80A and Nimonic 90). Lower wear and lower friction of superalloys was observed at high temperatures, as compared to room temperature. Surface morphological and surface analytical studies of fresh and worn surfaces were carried out using optical microscopy, 3D profilometer, scanning electron microscope, energy-dispersive X-ray spectroscopy and Raman spectroscopy to understand the friction and wear behaviour. The mechanism of the formation of microscale glaze layer is also discussed.

- by Prof Mohammad Farooq Wani
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- Materials Engineering, Mechanical Engineering, Tribology, Ceramics

... 8593. 23 R. Komanduri and TA Schroeder, On shear instability in machining nickel-based superalloy. J. Eng. ... 29 IA Choudhury, Machinability Studies of High Strength Materials and the Development of a Data Base System, Ph.D. Thesis,... more

The corrosion resistance of conventional (AA2024-T3, AA6082-T6 and AA7050-T7451) and the new generation (AA2050-T84, AA2098-T351, AA2198-T8, and AA2198-T851) precipitation-hardened alloys has been studied and compared using electrochemical and non-electrochemical approaches. The AA6082-T6 was the most resistant alloy followed by the new generation Al-Cu-Li alloys, except the AA2050-T84. All the alloys exhibited pseudo-passivity, except for the AA2024-T3 alloy which presented the highest number of pitting sites per cm 2 and also exhibited the most insidious form of corrosion amongst the alloys tested. However, the alloy with the highest corrosion depth was the AA2050-T84 alloy followed by the AA2024-T3 and AA7050-T7451 alloys. Intergranular corrosion was associated with rapid rates of penetration. In addition to the microstructural features of the alloys before corrosion, the modes of localized corrosion in the alloys were also influenced by evolving microstructural features (such as...

Super alloys are intensively used in various industries, especially in the aerospace industry, because of their special characteristics. A number of holes are sometimes required to be drilled into super alloys for aircraft at their final stage assembly. In the present study, a hybrid ultrasonic machining method, called rotary ultrasonic machining (RUM), was successfully used in super alloy drilling. The empirical modeling of the process parameters of RUM was performed for the super alloy (Inconel 718) using an experimental design approach, called response surface methodology (RSM). Parameters, namely tool rotation, feed rate, ultrasonic power, and abrasive grit size, were selected as input variables. The others were kept constant. The performance was measured in terms of the machining rate and the surface roughness. The developed models were found to be reliable representatives of the experimental results with prediction errors less than ±5%. Moreover, the feed rate for the quality and productivity aspect was found to be the most critical factor. The optimized values of the machining rate and the surface roughness achieved through a multi-response optimization were 0.9 825 mm 3 /s and 0.951 lm, respectively.

- by Dipesh Popli
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- Design of Experiments, Machining, ANOVA, Super Alloys

The present work demonstrates optimization of Wire Electrical Discharge Machining process parameters of Incoloy800 super alloy with multiple performance characteristics such as Material Removal Rate (MRR), surface roughness and Kerf based on the Grey-Taguchi Method. The process parameters considered in this research work are Gap Voltage, Pulse On-time, Pulse Off-time and Wire Feed. Taguchi's L 9 Orthogonal Array was used to conduct experiments. Optimal levels of process parameters were identified using Grey Relational Analysis and the relatively significant parameters were determined by Analysis of Variance. The variation of output responses with process parameters were mathematically modelled by using non-linear regression analysis method and the models were checked for their adequacy. Result of confirmation experiments shows that the established mathematical models can predict the output responses with reasonable accuracy.

- by Suresh babu Annamalai
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- Machining, Optimization, WEDM, Super Alloys

- by Dipesh Popli
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- Materials Science, Manufacturing, Design of Experiments, Machining

Manufacturing industries are moving toward super alloys owing to their unique features. In this article, the performance analysis of nickel-based super alloys has been studied on rotary ultrasonic machining (RUM) by varying the tool shapes and abrasive size of the diamond. The output quality of the machined part has been evaluated in terms of conicity and circularity of the hole. The machining process has been carried out by considering all the necessary RUM parameters like tool rotation, tool feed rate and ultrasonic power. The experimental setup validated that the lower value of conicity and circularity can be obtained at: tool rotation 4600 rpm, feed rate 0.013843 mm/s, ultrasonic power 60% abrasive size 140 mesh and using slotted tool. The variation in the abrasive size and the tool shapes has a significant effect on the performance of the machining.

- by Dipesh Popli
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- Design of Experiments, ANOVA, Super Alloys, Inconel 718

Purpose -The main objective of this experimental work is to analyze and measure the form tolerances namely flatness and squareness while machining a meso deep hole in EDM on Inconel-718 material plate. Design/methodology/approach -The experiments were performed on 15 amps rated SPARKONIX-EDM as per DOE (design of experiments). Kerosene was used as a dielectric along with constant pressure of 0.2 kg/cm 2 for all trial runs. The currents T on and T off were selected as process constraints to conduct experimental trials. The MRR, EWR, machining time and form tolerances were considered as output responses. The experimental outcomes were optimized by hybrid optimization using Taguchi and GRA (grey relational analysis) method. Findings -The EDM process parameters for Ni-based super alloy namely Inconel-718 had optimized by using GRA method coupled with Taguchi method. The optimum solution has been calculated for MRR, EWR, machining time and form tolerances namely squareness and flatness. The optimized parameters for the output responses in EDM process are Peak current (Ip) 12 Amps, 400 ms T on (pulse on time) and 10 ms T off (pulse off time). An attempt had also been made to attain Max. and Min. Evaluation of MRR and form tolerances, respectively. The attained optimum outcomes had also been examined through a real experiment and established to be satisfactory. Practical implications -This article will facilitate the defense, aerospace and EDM industries to improve their productivity with closer tolerances. Originality/value -The optimized parameters by multi-parametric optimization showed the considerable improvement in the process and will facilitate the defense, aerospace and EDM industries to improve their productivity with closer tolerances.

ABSTRACT Nickel alloys possess the excellent potential at high temperature and resistance to oxidation/corrosion owing to its high nickel content. These materials necessitate non-traditional machining methods. The rotary ultrasonic machining (RUM) process comes into existence as a superior alternative to the conventional machining of nickel alloys. The processing of these alloys using RUM needs attention. This article details the multi-response optimization in RUM of nickel alloy using the desirability concept. The present work is carried out with two shapes of the tool: (i) Plain tool and (ii) lateral slotted tool. During RUM, the process parameters—power rating tool rotation, abrasive diamond grit size and feed rate are varied. Compared with the plain tool, the lateral slotted tool shows the more efficient machining rate (MR) with less tool wear (TW). The micro-graphs disclose the mechanism of MR and TW during RUM.

- by Dipesh Popli
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- Materials Science, Non Traditional Machining, Design of Experiments, ANOVA

Nickel alloys possess the excellent potential at high temperature and resistance to oxidation/corrosion owing to its high nickel content. These materials necessitate non-traditional machining methods. The rotary ultrasonic machining (RUM) process comes into existence as a superior alternative to the conventional machining of nickel alloys. The processing of these alloys using RUM needs attention. This article details the multi-response optimization in RUM of nickel alloy using the desirability concept. The present work is carried out with two shapes of the tool: (i) Plain tool and (ii) lateral slotted tool. During RUM, the process parameters-power rating tool rotation, abrasive diamond grit size and feed rate are varied. Compared with the plain tool, the lateral slotted tool shows the more efficient machining rate (MR) with less tool wear (TW). The micro-graphs disclose the mechanism of MR and TW during RUM.

- by Dipesh Popli
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- Design of Experiments, ANOVA, Super Alloys, Rotary ultrasonic machining

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We present in this paper atomic scale Monte Carlo simulations of microstructure evolutions in the presence of atomic size mismatch, performed on a rigid lattice. The lattice statics formalism is used to obtain effective pair interactions (EPIs) from a continuous empirical description of alloy energetics that includes elastic relaxations in the harmonic approximation. These EPIs are long-ranged and are introduced in a Monte Carlo scheme to compute alloy properties. The influence of atomic size mismatch on EPIs as well as on microstructure evolutions is investigated in the case of a model binary fcc alloy. The microstructure evolution with atomic size mismatch operates mainly by shape changes and by the development of spatial correlations between precipitates. Our aim is also to provide a method to include elastic effects at the atomic scale starting from material macroscopic data, without any requirement of realistic continuous interatomic potential calibration. A commonly found approach in microscopic mean-field simulations is to use, at the atomic scale, effective elastic interactions inherited from continuum linear elasticity. We derive here a different and original method: the discrete lattice approach (DLA) that both converges to the continuum theory of elasticity (long-range aspect) and takes into account the discreteness of the lattice. It allows us to correctly reproduce the whole range of elastic interactions, down to the atomic scale, successfully improving the simple use of continuum elasticity, without the prior knowledge of any interatomic potential. Finally, the accuracy of the DLA is quantitatively verified through a detailed comparison between the microstructural evolutions obtained with this approach and the original lattice statics approach.

- by Celine Varvenne
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- Monte Carlo Methods, Elasticity, Super Alloys
- by Ajit Behera
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- Super Alloys
- by Rohit Khandelwal
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- Super Alloys

The role of temperature and load ratio (R) on the crack propagation rate (da/dN) of Alloys 276 and 617 under cyclic loading was investigated. The results indicate that the rate of cracking was gradually enhanced with increasing temperature when the R value was kept constant. However, the temperature effect was more pronounced at 100–150°C. Both alloys exhibited maximum da/dN values at a load range of 4.5 kN that corresponds to an R value of 0.1. The number of cycles to failure for Alloy 276 was relatively higher compared with that of Alloy 617, indicating its slower crack-growth rate. Fractographic evaluation of the broken specimen surface revealed combined fatigue and ductile failures.

- by Hasibul Hasan
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- Materials Engineering, Mechanical Engineering, Materials Science, Stress

PurposeThe main objective of this experimental work is to analyze and measure the form tolerances namely flatness and squareness while machining a meso deep hole in EDM on Inconel-718 material plate.Design/methodology/approachThe experiments were performed on 15 amps rated SPARKONIX-EDM as per DOE (design of experiments). Kerosene was used as a dielectric along with constant pressure of 0.2 kg/cm2 for all trial runs. The currents Ton and Toff were selected as process constraints to conduct experimental trials. The MRR, EWR, machining time and form tolerances were considered as output responses. The experimental outcomes were optimized by hybrid optimization using Taguchi and GRA (grey relational analysis) method.FindingsThe EDM process parameters for Ni-based super alloy namely Inconel-718 had optimized by using GRA method coupled with Taguchi method. The optimum solution has been calculated for MRR, EWR, machining time and form tolerances namely squareness and flatness. The optimiz...