Download or read book Solidification and Welding Metallurgy of Experimental Ni Base and Fe Base Superalloys Containing Nb Si and C written by John N. DuPont and published by . This book was released on 1997 with total page 644 pages. Available in PDF, EPUB and Kindle. Book excerpt: The solidification and weldability of experimental Ni base and Fe base superalloys containing Nb, Si, and C was studied using a combination of differential thermal analysis, quenching experiments, varestraint testing, and microstructural characterization techniques. The solidification reaction sequences responsible for microstructural development were found to be similar to those expected in the Ni-Nb-C ternary system. The solute rich interdendritic liquid exhibited two eutectic-type reactions at the terminal stages of solidification: $\rm L\to(\gamma + NbC$) and $\rm L\to(\gamma + Laves$). A pseudo ternary $\gamma$-Nb-C approach, modelled after the simple Ni-Nb-C system, was developed to provide a quantitative description of solidification behavior for these experimental alloys. Solute redistribution calculations in the model are based on a previous approach developed by Mehrabian and Flemings, with modifications made to account for the high diffusion rate of C in the solid. Solidification parameters for Nb and C were determined through DTA and electron probe microanalysis techniques and used as inputs to the model. Reasonable agreement is found between calculated volume fractions of the $\gamma$/NbC and $\gamma$/Laves constituents and those measured experimentally. The modelling results permit detailed descriptions of the relation between alloy composition and microstructural evolution during solidification. The results are also joined with experimental observations of fusion zone microstructures to determine the relation between alloy composition and solidification cracking susceptibility. A method is proposed for calculating the distribution of liquid in the solid + liquid zone as an aid to determining the individual effects of alloy composition on solidification cracking susceptibility.

Download or read book Welding Metallurgy and Weldability of Nickel Base Alloys written by John C. Lippold and published by John Wiley & Sons. This book was released on 2011-09-20 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Solidification Modeling of Nb Bearing Superalloys written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The solidification behavior of experimental Ni base and Fe base superalloys containing Nb, Si, and C was studied using differential thermal analysis (DTA) and microstructural characterization techniques. The solidification reaction sequences responsible for microstructural development were found to be similar to those expected in the Ni-Nb-C ternary system, where the solute-rich interdendritic liquid exhibited two eutectic-type reactions at the terminal stages of solidification: L[yields] ([gamma]+ NbC) and L[yields] ([gamma]+ Laves). A pseudo ternary[gamma]-Nb-C approach was developed to provide a quantitative description of solidification behavior for these experimental alloys. Solute redistribution calculations in the model are based on a previous approach developed by Mehrabian and Flemings, with modifications made to account for the high diffusion rate of C in the solid. Solidification parameters for Nb and C were determined through DTA and electron probe microanalysis techniques and used as inputs to the model. Reasonable agreement is found between calculated volume fractions of the[gamma]/NbC and[gamma]/Laves constituents and those measured experimentally. The modeling results permit detailed descriptions of the relation between alloy composition and microstructural evolution during solidification.

Download or read book Trends In Welding Research written by Stan A. David and published by ASM International. This book was released on 2006-01-01 with total page 1015 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dissertation Abstracts International written by and published by . This book was released on 1997 with total page 824 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Superalloys 2012 written by Eric S. Huron and published by John Wiley & Sons. This book was released on 2012-10-02 with total page 952 pages. Available in PDF, EPUB and Kindle. Book excerpt: A superalloy, or high-performance alloy, is an alloy that exhibits excellent mechanical strength at high temperatures. Superalloy development has been driven primarily by the aerospace and power industries. This compilation of papers from the Twelfth International Symposium on Superalloys, held from September 9-13, 2012, offers the most recent technical information on this class of materials.

Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 1020 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Alloy Design and Characterization of Strengthened Nickel based Superalloys for Additive Manufacturing written by Jinghao Xu and published by Linköping University Electronic Press. This book was released on 2021-01-28 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Physical Metallurgy of Nickel base Superalloys written by C. H. Lund and published by . This book was released on 1961 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Parametric Analysis of Solidification in Y Fe Ni Cr Nb C Alloys written by and published by . This book was released on 1999 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: A parametric analysis is presented which summarizes the amount of total ([gamma]/NbC + [gamma]/Laves) and individual [gamma]/NbC and [gamma]/Laves constituents which form during solidification of [gamma]{sub (Fe, Ni, Cr)} alloys with variations in nominal Nb and C contents. Calculated results are presented for Fe base alloys and Ni base alloys. The results provide a quantitative rationale for understanding the relation between alloy composition and solidification microstructures and should provide useful insight into commercial alloys of similar composition.

Download or read book American Doctoral Dissertations written by and published by . This book was released on 1996 with total page 872 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Welding and Weldability of Directionally Solidified Single Crystal Nickel Base Superalloys written by and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Nickel-base superalloys are used extensively in high-temperature service applications, and in particular, in components of turbine engines. To improve high-temperature creep properties, these alloys are often used in the directionally-solidified or single-crystal form. The objective of this CRADA project was to investigate the weldability of both experimental and commercial nickel-base superalloys in polycrystalline, directionally-solidified, and single-crystal forms.

Download or read book Metallurgical Transactions written by and published by . This book was released on 1993 with total page 1182 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Carbon Additions and Grain Defect Formation in Directionally Solidified Nickel base Superalloys written by Sammy Tin and published by . This book was released on 2001 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Experiments on the Undirectional Solidification of the Nickel base Alloy 713C written by J. E. Northwood and published by . This book was released on 1969 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Creep and Microstructural Stability of Ruthenium containing Nickel base Single Crystal Superalloys written by Laura Jill Rowland and published by . This book was released on 2005 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Metals Abstracts written by and published by . This book was released on 1998 with total page 1076 pages. Available in PDF, EPUB and Kindle. Book excerpt: