Microstructural Rejuvenation Through Non-conventional Heat Treatments of an Inconel 939 Superalloy

2012 ◽  
Vol 1372 ◽  
Author(s):  
M. A. González ◽  
D. I. Martínez ◽  
A. Pérez ◽  
H. Guajardo
Keyword(s):  
Heat Treatment ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Heat Treatments ◽  
Homogeneous Microstructure ◽  
Conventional Microscopy ◽  
Cast Superalloy ◽  
Scanning Electron

ABSTRACTThe microstructural rejuvenation through non-conventional heat treatments (NCHT) of a conventional cast superalloy Inconel 939 was investigated. The primary and secondary main constituents of the NCHT microstructures were characterized through its morphology and composition applying conventional microscopy and analytical scanning electron microscope (SEM). The results showed a complete rejuvenation of the overage microstructure (disordered coarse cuboids of 1.2μm from γ´, continuous films of M23C6 carbides and coarse MC carbides as well as γ-γ´eutectics) into a more homogeneous microstructure; spherical ordered primary γ´ and secondary γ´ precipitates ranging between 357 to 442 nm and 30 to50 nm respectively and depending on the applied heat treatment. Also blocky type MC and discreet M23C6 carbides dispersed within the dendrite and in the interdendritic regions were observed. There was no evidence of the formation of detrimental phases with the NCHT, which can affect the long-term properties of the alloy during service.

Effect of Double-Step Solution Treatment on Rejuvenation Heat Treated Microstructure of IN-738 Superalloy

2020 ◽  
Vol 856 ◽  
pp. 36-42
Author(s):  
Chuleeporn Paa-Rai
Keyword(s):  
Heat Treatment ◽  
Image Analysis ◽  
Electron Microscope ◽  
Solution Treatment ◽  
Single Step ◽  
Double Step ◽  
Heat Treated ◽  
Cast Superalloy ◽  
Scanning Electron

This work investigates the effect of rejuvenation heat treatment, with double-step solution treatment at the temperature from 1150 °C to 1200 °C, on the recovered microstructure of IN-738 cast superalloy. The superalloy has been long-term exposed as a turbine blade in a gas turbine prior to this study. After double solution treatment and aging at 845 °C for 12 h and 24 h, the recovered microstructures were examined by using a scanning electron microscope. Coarse γ΄ particles, that have presented in damaged microstructures, could not be observed in the samples after the rejuvenation heat treatment. In addition, the image analysis illustrates that the reprecipitated γ΄ particles in the samples with double-step solution treatments increase significantly in sizes during aging than that in the samples with the single-step solution treatment. Furthermore, the measurement of the samples hardness presents that the as-receive sample hardness is improved after rejuvenation heat treatment studied in this work.

Scanning Transmission Imaging of Elastomer Blends Using an Unmodified Conventional Scanning Electron Microscope

1995 ◽  
Vol 68 (2) ◽  
pp. 342-350 ◽  
Author(s):  
Paul E. F. Cudby ◽  
Barry A. Gilbey
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Scanning Transmission Electron Microscopy ◽  
Transmission Imaging ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Novel Method ◽  
Conventional Microscopy ◽  
Microscopy Techniques ◽  
Scanning Electron

Abstract A novel method for carrying out scanning transmission electron microscopy on a standard scanning electron microscope is described. This method involves the addition of a specially fabricated mount and is accomplished without carrying out any form of modification on the microscope. The method is compared to more conventional microscopy techniques and examples are given showing the advantages of this system.

scholarly journals Effects of heat treatment and strain rate on the microstructure and mechanical properties of 6061 Al alloy

2015 ◽  
Vol 25 (1) ◽  
pp. 26-41 ◽  
Author(s):  
Ling Li ◽  
EA Flores-Johnson ◽  
Luming Shen ◽  
Gwénaëlle Proust
Keyword(s):  
Heat Treatment ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Electron Back Scatter Diffraction ◽  
Micro Cracks ◽  
Strain Rate Compression ◽  
Scanning Electron

In the present work, the effects of heat treatment and strain rate on mechanical behaviour and microstructure evolution of aluminium alloy 6061 have been investigated. The micro-crack initiation and crystallographic texture evolution are obtained from scanning electron microscope and electron back-scatter diffraction experiments. Quasi-static and high strain rate compression tests are conducted on AA6061 specimens that underwent two different heat treatments: the as-received material with the original T6 heat treatment and the heat treated and artificially aged specimens. For the high strain rate compression (∼2000 and ∼4000 s−1) tests, the split Hopkinson pressure bar apparatus is used. It is observed that the additional heat treatment has significantly reduced the yield strength of the material. Furthermore, electron back-scatter diffraction results show that the higher the applied strain rate is, the less significant change will happen to the texture. Scanning electron microscope images show that, for both T6 and HT specimens, the number and size of micro-cracks in the dynamic compressed specimens are smaller than in the quasi-static deformed specimen. Therefore, the strain rate is considered to be the dominant factor in forming micro-cracks.

scholarly journals PENGAMATAN STRUKTUR MIKRO PADA KOROSI ANTAR BUTIR DARI MATERIAL BAJA TAHAN KARAT AUSTENITIK SETELAH MENGALAMI PROSES PEMANASAN

2009 ◽  
Vol 3 (2) ◽  
pp. 107
Author(s):  
Anwar Budianto ◽  
Kristina Purwantini ◽  
BA Tjipto Sujitno
Keyword(s):  
Heat Treatment ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Holding Time ◽  
Energy Dispersive ◽  
X Ray ◽  
Ss 304 ◽  
Scanning Electron

PENGAMATAN STRUKTUR MIKRO PADA KOROSI ANTAR BUTIR DARI MATERIAL               BAJA      TAHAN KARAT                             AUSTENITIK             SETELAH MENGALAMI PROSES HEAT PEMANASAN. Telah dilakukan pengamatan korosi  antar  butir pada  material  baja tahan karat  austenitik  jenis  SS 304 setelah mengalami proses perlakuan panas (heat treatment) pada selang suhu (400-950) oC dengan variasi waktu pemanasan (holding time) yaitu 1 jam, 3 jam, 3,5 jam, dan  4 jam.  Sebelum dan sesudah proses perlakuan panas, struktur mikro sampel dianalisis menggunakan   mikroskop   optik   dan   SEM   (Scanning   Electron   Microscope). Komposisi kimia pada daerah di sekitar batas butir diamati menggunakan SEM-EDS (Energy  Dispersive  X-ray  Spectrometer).  Hasil  pengamatan  menunjukkan  bahwasampel yang mengalami perlakuan panas di bawah suhu sensitisasi yakni pada suhu400 oC, ternyata korosi antar butir tidak teramati. Untuk sampel yang mengalami perlakuan panas pada suhu sensitisasi yakni pada selang suhu (500-900) oC, ternyata korosi antar butir dapat teramati dengan jelas. Sedangkan untuk sampel yang mengalami perlakuan panas di atas suhu sensitisasi yaitu pada suhu 950 oC, ternyata korosi antar butir masih dapat teramati tetapi tidak sejelas sampel yang mengalami perlakuan panas pada suhu sensitisasi. Dari analisis komposisi kimia di sekitar batas butir ditemukan adanya penurunan kandungan karbon (C) yaitu dari 0,61 % massamenjadi 0,47 %massa, dan untuk khrom (Cr) dari 18,37 % massa menjadi 17,76 %massa. 

Electrohydrodynamic Casting Polymeric Carbon Nanofibers From Different Precursors for the Hyperthermia Application

2018 ◽  
Author(s):  
Nadia N. Boutros ◽  
Ann D. Chen ◽  
Ryan N. Gan ◽  
Yong X. Gan
Keyword(s):  
Heat Treatment ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Carbon Nanofiber ◽  
Test Sample ◽  
Fiber Composites ◽  
Metal Salts ◽  
Heat Treated ◽  
Polymeric Carbon ◽  
Scanning Electron

The purpose of this work was to develop and analyze different materials that would be able to create the partially carbonized nanofibers through electrohydrodynamic casting followed by heat treatment. Test samples were created with different precursors containing polymer solutions and different added metal salts. After performing a series of steps to create each test sample, the sample was heat-treated to generate carbon nanofiber composites. The morphology of the carbon nanofiber composites was observed using a scanning electron microscope. Hyperthermia tests on typical fiber composites were performed.

Chain Segment Analysis

2015 ◽  
Vol 647 ◽  
pp. 216-221
Author(s):  
David Jech ◽  
Lenka Klakurková ◽  
Ladislav Čelko ◽  
Pavel Doležal ◽  
Jiří Švejcar
Keyword(s):  
Heat Treatment ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Base Material ◽  
Hardness Measurement ◽  
Material Structure ◽  
Chain Segment ◽  
Main Interest ◽  
Scanning Electron

The work is aimed at a detailed analysis of impaired chain segments manufactured by welding and determining the cause of chain segment failure. The main interest was focused on the base material structure, the quality of weld joint, the heat treatment of the weldment, and the overall condition of the component after operating workload. The chain segments were investigated in terms of the microstructure by means of the light microscope, scanning electron microscope equipped with an energy dispersive microanalyser, and hardness measurement.

Research on Pinholes in Aluminum Foil

2014 ◽  
Vol 884-885 ◽  
pp. 308-311
Author(s):  
Qing Wei Dai ◽  
Ding Fei Zhang ◽  
Xi Chen ◽  
Jing Ren Dong ◽  
Fu Sheng Pan
Keyword(s):  
Heat Treatment ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Optical Microscopy ◽  
Energy Dispersive Spectrometer ◽  
Aluminum Foil ◽  
Energy Dispersive ◽  
Treatment Processes ◽  
Scanning Electron

To investigate pinholes in 8079 Aluminum foil, optical microscopy and scanning electron microscope with energy dispersive spectrometer were adopted. Results show that four types of pinholes in 8079 aluminum foil, (1) small size, rod-shaped, (2) pinhole in groove, (3) hole with big size, (4) crumpled pinholes. Big compounds along with all rolling and heat treatment processes cause the small rod-shaped pinhole. The big compound contains elements of Al-Fe-O.

An Electrospinning Approach to Polyaniline Nanofibers by Template

2007 ◽  
Vol 121-123 ◽  
pp. 579-582 ◽  
Author(s):  
Hui Min Huang ◽  
Z.Y. Li ◽  
C. Wang
Keyword(s):  
Heat Treatment ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Ir Spectra ◽  
Energy Dispersive ◽  
Composite Fibers ◽  
X Ray ◽  
Polyaniline Nanofibers ◽  
Ft Ir ◽  
Scanning Electron

Polyaniline doped with camphorsulfonic acid (PANI.HCSA) nanofibers have been successfully prepared using “nanofibers template” via electrospinning. The PVA nanofibers were used as a template to get the PANI/PVA composite fibers. After removing the template by heat treatment, the PANI fibers were obtained. Scanning electron microscope (SEM) with the Energy Dispersive X-Ray Spectrometer software (EDX) and FT-IR spectra were used to characterize the composite fibers and the PANI.HCSA nanofibers. The average diameters of the composite fibers obtained and PANI fibers were 920 nm and 530 nm, respectively.

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