scholarly journals Mechanical and Microstructural Characterization of Plasma Welded Joints of 18 Ni-300 Maraging Steels Subjected to Repairs

2021 ◽  
Vol 5 (1) ◽  
pp. 5-20
Author(s):  
Paulo Roberto Sakai ◽  
Deivid Ferreira da Silva ◽  
Milton S�rgio Fernandes de Lima ◽  
Rafael Humberto Mota de Siqueira ◽  
Antonio Jorge Abdalla
Keyword(s):  
Welded Joints ◽  
Microstructural Characterization ◽  
Maraging Steels

scholarly journals Microstructural Characterization of Some Turbine Blade Martensitic Stainless Steels

2019 ◽  
Vol 70 (4) ◽  
pp. 1132-1139
Author(s):  
Andrei Constantin Berbecaru ◽  
George Coman ◽  
Catalin Stefan Gradinaru ◽  
Mirela Gabriela Sohaciu ◽  
Cristian Predescu ◽  
...  
Keyword(s):  
Stainless Steels ◽  
Energy Dispersive Spectrometry ◽  
Microstructural Characterization ◽  
Structural Modifications ◽  
Maraging Steels ◽  
Martensitic Stainless Steels ◽  
The Third ◽  
Hardness Values ◽  
Quenching And Tempering

The paper presents microstructural features of three stainless steels utilized in making hydropower turbine parts. Two of these steels were already used in producing these parts, the third one is newly conceived. Aiming better mechanical and corrosion resistance characteristics, steels were produced using an induction furnace with cold crucible under vacuum and argon atmosphere, striving for an inclusion � free state. Quenching and tempering heat treatments were subsequently applied. The microstructural investigations, carried-out by microhardess testing, optical and scanning electron microscopy (SEM) associated with energy dispersive spectrometry (EDS), were able to explain the structural modifications. Refined microstructures were found in the two first steels. Concerning the third one, a precipitation phenomenon of intermetallic compounds such as Ni3(Ti,Mo) was reported, similar to that encountered in the maraging steels class. Mechanical properties of this steel are very different from classic martensitic stainless steels ones. Specifically, after tempering the hardness values do not decrease as in other steels, but increase about 1.6 times. Thus a new steel category with duplex properties is reported.

Mechanical and microstructural characterization of laser-welded joints of 6013-T4 aluminum alloy

2014 ◽  
Vol 37 (1) ◽  
pp. 133-140 ◽  
Author(s):  
Rafael Humberto Mota de Siqueira ◽  
Aline Capella de Oliveira ◽  
Rudimar Riva ◽  
Antonio Jorge Abdalla ◽  
Carlos Antonio Reis Pereira Baptista ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Welded Joints ◽  
Microstructural Characterization

Microstructural Characterization of Ultrasonically Welded Aluminum

2005 ◽  
Vol 127 (1) ◽  
pp. 65-74 ◽  
Author(s):  
S. M. Allameh ◽  
C. Mercer ◽  
D. Popoola ◽  
W. O. Soboyejo
Keyword(s):  
Mechanical Properties ◽  
Welded Joints ◽  
Weld Zone ◽  
Microstructural Characterization ◽  
Weld Interface ◽  
Fatigue Properties ◽  
Second Phase ◽  
Welding Time ◽  
Second Phase Particles

The microstructure and mechanical properties of ultrasonically welded AA6111-T4 specimens are discussed. The effects of welding time on the mechanical properties of welded joints are investigated. A longer welding time results in a more continuous welded interface and higher yield and fracture strengths. Accordingly, fatigue properties of the welded specimens with longer welding times are improved. The results of electron microscopy on the cross section of ultrasonically welded joints show three distinct zones: weld zone, weld affected zone and compression zone each with a distinct microstructure. TEM results show nanocrystalline grains along with second phase particles in the range of 15–25 nm in the weld zone. Flow patterns consistent with the geometry of weld–tip were observed at the weld interface.

Microstructural characterization of grade 300 and grade 350 maraging steels and electrochemical study in hydrofluoric solution

2021 ◽  
Vol 243 ◽  
pp. 109738
Author(s):  
Mauro Andrés Cerra Florez ◽  
Úrsula Cid Pereira ◽  
Jorge Luiz Cardoso ◽  
Francisco José dos Santos Oliveira ◽  
Walney Silva Araújo ◽  
...  
Keyword(s):  
Microstructural Characterization ◽  
Electrochemical Study ◽  
Maraging Steels

scholarly journals Nondestructive Microstructural Characterization of Austenitic-Ferritic Stainless Steel Welded Joints by Double Loop Electrochemical Polarization Reactivation Portable Test

2022 ◽  
Vol 25 ◽  
Author(s):  
Brígida Bastos de Almeida ◽  
Andréia de Souza Martins Cardoso ◽  
Pedro Soucasaux Pires Garcia ◽  
Hugo Ribeiro da Igreja ◽  
Rodrigo Chales ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Ferritic Stainless Steel ◽  
Welded Joints ◽  
Microstructural Characterization ◽  
Double Loop ◽  
Electrochemical Polarization

Microstructural characterization of CoPtCr/Cr thin film disks by cross-section TEM and elongated probe micro-diffraction

1991 ◽  
Vol 49 ◽  
pp. 762-763
Author(s):  
M.A. Parker ◽  
K.E. Johnson ◽  
C. Hwang ◽  
A. Bermea
Keyword(s):  
Magnetic Recording ◽  
Electron Probe ◽  
Microstructural Characterization ◽  
Crystallographic Structure ◽  
Recording Media ◽  
Layer By Layer ◽  
Cross Sectional ◽  
New Techniques ◽  
Polished Side

We have reported the dependence of the magnetic and recording properties of CoPtCr recording media on the thickness of the Cr underlayer. It was inferred from XRD data that grain-to-grain epitaxy of the Cr with the CoPtCr was responsible for the interaction observed between these layers. However, no cross-sectional TEM (XTEM) work was performed to confirm this inference. In this paper, we report the application of new techniques for preparing XTEM specimens from actual magnetic recording disks, and for layer-by-layer micro-diffraction with an electron probe elongated parallel to the surface of the deposited structure which elucidate the effect of the crystallographic structure of the Cr on that of the CoPtCr.XTEM specimens were prepared from magnetic recording disks by modifying a technique used to prepare semiconductor specimens. After 3mm disks were prepared per the standard XTEM procedure, these disks were then lapped using a tripod polishing device. A grid with a single 1mmx2mm hole was then glued with M-bond 610 to the polished side of the disk.

Microstructural Characterization of Au-Ge-Ni based ohmic contacts to GaAs/AlGaAs modfet device

1987 ◽  
Vol 45 ◽  
pp. 326-327
Author(s):  
A.K. Rai ◽  
A.K. Petford-Long ◽  
A. Ezis ◽  
D.W. Langer
Keyword(s):  
Contact Resistance ◽  
Ohmic Contact ◽  
Ohmic Contacts ◽  
Microstructural Characterization ◽  
Almost Everywhere ◽  
Spacer Layer ◽  
Good Contact ◽  
The Relationship ◽  
Lower Contact

Considerable amount of work has been done in studying the relationship between the contact resistance and the microstructure of the Au-Ge-Ni based ohmic contacts to n-GaAs. It has been found that the lower contact resistivity is due to the presence of Ge rich and Au free regions (good contact area) in contact with GaAs. Thus in order to obtain an ohmic contact with lower contact resistance one should obtain a uniformly alloyed region of good contact areas almost everywhere. This can possibly be accomplished by utilizing various alloying schemes. In this work microstructural characterization, employing TEM techniques, of the sequentially deposited Au-Ge-Ni based ohmic contact to the MODFET device is presented.The substrate used in the present work consists of 1 μm thick buffer layer of GaAs grown on a semi-insulating GaAs substrate followed by a 25 Å spacer layer of undoped AlGaAs.

Microstructural characterization of a cast RENi5-based alloy

1993 ◽  
Vol 51 ◽  
pp. 1176-1177
Author(s):  
G. M. Micha ◽  
L. Zhang
Keyword(s):  
Electron Microscopy ◽  
Rare Earth ◽  
Microstructural Characterization ◽  
Binary Compound ◽  
Nickel Metal ◽  
Cast Material ◽  
Nickel Metal Hydride ◽  
Transmission Electron ◽  
Cast Condition

RENi5 (RE: rare earth) based alloys have been extensively evaluated for use as an electrode material for nickel-metal hydride batteries. A variety of alloys have been developed from the prototype intermetallic compound LaNi5. The use of mischmetal as a source of rare earth combined with transition metal and Al substitutions for Ni has caused the evolution of the alloy from a binary compound to one containing eight or more elements. This study evaluated the microstructural features of a complex commercial RENi5 based alloy using scanning and transmission electron microscopy.The alloy was evaluated in the as-cast condition. Its chemistry in at. pct. determined by bulk techniques was 12.1 La, 3.2 Ce, 1.5 Pr, 4.9 Nd, 50.2 Ni, 10.4 Co, 5.3 Mn and 2.0 Al. The as-cast material was of low strength, very brittle and contained a multitude of internal cracks. TEM foils could only be prepared by first embedding pieces of the alloy in epoxy.

Microstructural Characterization of Open-Pore Metal Foams of Pure Metals

2015 ◽  
Vol 52 (2) ◽  
pp. 83-107 ◽  
Author(s):  
B. S. Mocker ◽  
A. M. Matz ◽  
N. Jost ◽  
P. Krug
Keyword(s):  
Microstructural Characterization ◽  
Metal Foams ◽  
Pure Metals

Microstructural characterization of a carbonitrided heat resisting alloy using focused ion beam-based techniques

2005 ◽  
Vol 22 (3) ◽  
pp. 351-358 ◽  
Author(s):  
S. Ford ◽  
D.J. Young ◽  
D. McGrouther ◽  
P.R. Munroe
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Microstructural Characterization
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