Effect of Microstructure Evolution and Corrosion Behavior on Phase Transformation of Nanocrystalline SUS304 Prepared by Dry Ice Shot Peening

2022 ◽  
Vol 10 (1) ◽  
pp. 9-14
Keyword(s):  
Corrosion Resistance ◽  
Phase Transformation ◽  
Electron Microscope ◽  
Corrosion Behavior ◽  
Shot Peening ◽  
Martensite Phase ◽  
Metallic Component ◽  
Dry Ice ◽  
High Deformation ◽  
Transmission Electron

Microstructure and corrosion behavior of nanocrystalline SUS304 by dry ice shot peening has been investigated in detail in term of phase transformation. SUS304 as metastable austenitic stainless has excellent corrosion resistance and induced martensite by shot peening process. However, the SUS304 has quite low strength which is difficult to wear as metallic component. The dry ice shot peening process was carried out on SUS304 surface for one and three hours. The microstructure was observed by transmission electron microscope (TEM) and scanning electron microscope (SEM) equipped with electron back-scattered diffraction (EBSD). The phase transformation was analyzed by X-ray diffraction (XRD). The corrosion testing was carried out in 3.5% NaCl solution. The result indicated that the grain size of SUS304 surface was finer by deformation due to dry ice shot peened process. The hardness was improved properly by the increasing the shot peened time, and the corrosion resistance was increased. The XRD results showed that three hours shot peening process induced martensite phase of SUS304 by 15 m thickness. It can be summarized that the dry ice shot peening can be induced phase transformation due to high deformation on the SUS304 surface

Analyses of Phase Transformation Mechanism Based on In Situ Observation during Ti-10Nb-5Sn Alloy Heating Cycles

2012 ◽  
Vol 549 ◽  
pp. 535-538
Author(s):  
Yan Li ◽  
Jie Qi ◽  
Chuan Xin Zhai ◽  
Ran Feng Qiu
Keyword(s):  
Phase Transformation ◽  
Electron Microscope ◽  
Shape Memory ◽  
Transmission Electron Microscope ◽  
Memory Function ◽  
Martensite Phase ◽  
Round Trip ◽  
Transformation Mechanism ◽  
Transmission Electron

The Ti-10Nb-5Sn alloy was heated and cooled repeatedly in a heater system located in transmission electron microscope chamber. The phase and morphology transformation was in situ observed to analyze the transformation mechanism from austenite β to martensite phase. The results reveal that he Ti-10Nb-5Sn alloy has round trip shape memory function.

Study on Microstructure of Quenched Martensite in W6Mo5Cr4V2 Steel

2011 ◽  
Vol 295-297 ◽  
pp. 175-178
Author(s):  
Yun Ping Ji ◽  
Zong Chang Liu ◽  
Hui Ping Ren
Keyword(s):  
Phase Transformation ◽  
Small Area ◽  
Martensite Phase ◽  
Stacking Fault ◽  
Plate Martensite ◽  
Twin Crystal ◽  
Transmission Electron ◽  
Starting Point ◽  
Austenite Grains ◽  
The Difference

The microstructure and the formation mechanism of martensite in W6Mo5Cr4V2 steel was studied by metallographic microscope and JEM-2100 transmission electron microscope after the samples were austenized between the temperatures of Ac1~Accm and then quenched. The results show that When heating W6Mo5Cr4V2 steel samples between the temperatures of Ac1~Accm and then quenching, the cryptocrystalline martensite will be obtained. The cryptocrystalline martensite is plate martensite actually. It is considered that the formation cause of the cryptocrystal martensite is extremely inhomogeneous chemical composition in the austenite grains and the difference of martensite starting point (Ms point) of every small area in austenite grains. Besides the high-density dislocation and the fine twin crystal, the substructure of the cryptocrystalline martensite includes the superfine stacking fault. The stacking fault is caused by the stacking misarrangement during the crystal lattice reconstruction of martensite phase transformation. The midrib exists in the cryptocrystal martensite of W6Mo5Cr4V2 steel, which is composed of the fine twin crystal plates. The shear mechanism can not account for the formation of the martensite midrib.

Corrosion Resistance of Ni-Y2O3 Composite Coating Prepared by Electrodeposition under Ultrasonic Condition

2010 ◽  
Vol 97-101 ◽  
pp. 1235-1238 ◽  
Author(s):  
Yu Jun Xue ◽  
Chen Shen ◽  
Ji Shun Li ◽  
Hang Li ◽  
Dong Hong Si
Keyword(s):  
Aqueous Solution ◽  
Corrosion Resistance ◽  
Electron Microscope ◽  
High Resolution ◽  
Surface Morphology ◽  
Composite Coatings ◽  
Nanocomposite Coating ◽  
Transmission Electron ◽  
Superior Corrosion Resistance ◽  
Electronic Microscope

Ni-Y2O3 nanocomposite coating was electrodeposited from a nickel sulfamate solution containing Y2O3 particles and ultrasonic was applied during the process of the electrodeposition. The surface morphology and microstructure of the composite coatings were analyzed by a scanning electronic microscope (SEM) and a high-resolution transmission electron microscope (HRTEM). The corrosion resistence of the coatings was evaluated in the solution of 10 wt.% HCl aqueous solution. The results indicate that the Ni-Y2O3 nanocomposite coating shows a refined crystal grain and improved corrosion resistance compared with pure Ni coating. The Ni-Y2O3 nanocomposite coating prepared under ultrasonic condition exhibits a superior corrosion resistance due to the formation of denser structure and finer-grain scale.

The Investigation of Microstructure of Pt/Ti Explosive Clad Interface

2005 ◽  
Vol 475-479 ◽  
pp. 3855-3858 ◽  
Author(s):  
Shi Zhong Wei ◽  
Yan Li ◽  
Jin Hua Zhu
Keyword(s):  
Electron Microscope ◽  
Crystal Size ◽  
Energy Dispersive Spectrometer ◽  
Martensite Phase ◽  
Crystal Layer ◽  
Orthorhombic Crystal System ◽  
Orthorhombic Crystal ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Microstructure in anchoring site of Pt/Ti explosive clad Plate was observed, tested and analyzed by analytical and high resolution transmission electron microscope, X-ray diffractometer, scanning electron microscope and energy-dispersive spectrometer. An intermittent micro-crystal layer was observed in anchoring area, with thickness of 2 um. The inner crystal size was from some nanometer. to hundreds of nanometer. Some crystal had defects in it, such as staggered layer. The layer was composed of metal compound, like PtTi，Pt5Ti3，Pt3Ti，Ti3Pt and etc. The direct Pt—Ti anchoring area, hexagonal Ti variation-orthorhombic crystal system, α″-Ti metastable martensite phase and bicrystals with partial deformation were also observed. The research of microstructure in anchoring area revealed the nature of explosive compound in metallurgical anchoring.

Nanometer-area diffraction of small iron crystallites in single crystalline Fe-MgO composite films

1988 ◽  
Vol 46 ◽  
pp. 706-707
Author(s):  
N. Tanaka ◽  
K. Mihama ◽  
H. Ou ◽  
J.M. Cowley
Keyword(s):  
Phase Transformation ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Carbon Film ◽  
Composite Films ◽  
High Resolution Electron Microscopy ◽  
Scanning Transmission Electron Microscope ◽  
Specimen Preparation ◽  
Single Crystalline ◽  
Transmission Electron

Nanometer-sized iron(Fe) crystallites can be prepared in a single crystalline magnesium oxide(MgO) film by a simultaneous vacuum deposition of Fe and MgO. The crystallites are grown epitaxially and almost coherently in the film, the orientation being (001) [110]Fe//(001)[100]MgOand (011) [100]Fe//(001) [100]MgO. A heat treatment of the as-grown composite films at 500-1000°C brings about a phase-transformation from α -iron(b.c.c.) to γ -iron(f.c.c.). In the present study, the phase-transformation and the structure of the γ-iron crystallites are studied by nanometer-area electron diffraction(nanodiffraction) in TEM and STEM as well as high-resolution electron microscopy.The specimens were single crystalline Fe-MgO composite films prepared on a NaCl (001 ) surface by co-evaporation of Fe and MgO. The films were separated from the substrate in water and mounted on a perforated carbon film. Nanodiffraction in TEM was performed in a 200 kV transmission electron microscope(JEM- 2000FX)2 and that in STEM3was carried out in a 100 kV scanning transmission electron microscope (VG-HB5) equipped with a specimen-preparation chamber.

scholarly journals Corrosion Behavior of Zinc-Graphite Metal Matrix Composite in 1 M of HCl

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
M. A. Afifi
Keyword(s):  
Corrosion Resistance ◽  
Electron Microscope ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Metal Matrix ◽  
Optical Microscope ◽  
Powder Metallurgy Method ◽  
Pure Zinc ◽  
Graphite Composites ◽  
Scanning Electron

This paper is aimed at investigating the corrosion behavior of Pure and Zinc-graphite particles with percentage of 1, 3, and 5%, respectively. The composites were fabricated by powder metallurgy method. Corrosion tests were performed according to ASTM standard. Corrosion rate was calculated and it is found that in all cases the corrosion rate was decreasing with the increase in exposure time. Meanwhile, the microstructure of composites was imaged and analyzed using optical microscope and scanning electron microscope. It is observed that the best corrosion resistance was zinc with 1% Graphite while Zinc with 3% and 5% Graphite composites did not enhance the corrosion resistance comparing to pure Zinc.

The L12 to DO19 Phase Transformation In The Intermetallic Compound Fe3Ge

1997 ◽  
Vol 481 ◽  
Author(s):  
Q. Z. Chen ◽  
A. H. W. Ngan ◽  
B. J. Duggan
Keyword(s):  
Phase Transformation ◽  
Electron Microscope ◽  
Intermetallic Compound ◽  
Transmission Electron Microscope ◽  
Stacking Fault ◽  
Transmission Electron ◽  
Do19 Phase ◽  
Annealing Experiments

ABSTRACTA large kinetics hysteresis is found to exist between the forward and backward reactions of the L12 ↔ DO19 transformation in Fe3Ge. The slow DO19 to L12 transformation leaves behind very stable twins and stacking fault debris. In-situ annealing experiments in the transmission electron microscope revealed that nucleation for the reverse L12 to DO19 reaction takes place efficiently at these defects.

In Situ Observation of Electron Beam-Induced Phase Transformation of CaCO3 to CaO via ELNES at Low Electron Beam Energies

2014 ◽  
Vol 20 (3) ◽  
pp. 715-722 ◽  
Author(s):  
Ute Golla-Schindler ◽  
Gerd Benner ◽  
Alexander Orchowski ◽  
Ute Kaiser
Keyword(s):  
Phase Transformation ◽  
Electron Beam ◽  
Electron Microscope ◽  
Bond Length ◽  
Transmission Electron Microscope ◽  
Low Voltage ◽  
In Situ Observation ◽  
Edge Structure ◽  
Transmission Electron

AbstractIt is demonstrated that energy-filtered transmission electron microscope enables following of in situ changes of the Ca-L2,3 edge which can originate from variations in both local symmetry and bond lengths. Low accelerating voltages of 20 and 40 kV slow down radiation damage effects and enable study of the start and finish of phase transformations. We observed electron beam-induced phase transformation of single crystalline calcite (CaCO3) to polycrystalline calcium oxide (CaO) which occurs in different stages. The coordination of Ca in calcite is close to an octahedral one streched along the <111> direction. Changes during phase transformation to an octahedral coordination of Ca in CaO go along with a bond length increase by 5 pm, where oxygen is preserved as a binding partner. Electron loss near-edge structure of the Ca-L2,3 edge show four separated peaks, which all shift toward lower energies during phase transformation at the same time the energy level splitting increases. We suggest that these changes can be mainly addressed to the change of the bond length on the order of picometers. An important pre-condition for such studies is stability of the energy drift in the range of meV over at least 1 h, which is achieved with the sub-Ångström low-voltage transmission electron microscope I prototype microscope.

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