Effect of Nanoadditives on the Structure and Properties of Austempered Ductile Irons

2018 ◽  
Vol 919 ◽  
pp. 34-42
Author(s):  
Julieta Atanasova Kaleicheva ◽  
Valentin Plamenov Mishev
Keyword(s):  
Impact Toughness ◽  
Cubic Boron Nitride ◽  
Optical Metallography ◽  
Nanosized Particles ◽  
Structure And Properties ◽  
Cast Irons ◽  
X Ray ◽  
Resistance Increase ◽  
Bainitic Structure ◽  
Scanning Electron

In the present study austempered ductile irons (ADI) with an upper and lower bainitic structure with nanosized particles of cubic boron nitride cBN (50nm) are studied. The austempering modes include austenization at 900оС during an hour and isothermal retention at 280оС from 0.5 to 6 hours and at 380oС from 0.5 to 6 hours. The samples microstructure is investigated by means of an optical metallography, scanning electron microscopy and X-ray analysis. Tests for hardness, impact toughness and wear are performed. The influence of nanosized additives on the kinetic of the bainitic transformation and on the morphology of the obtained bainitic structure is studied. It is established that the changes of the bainitic cast irons microstructure under influence of the nanoparticles of cBN lead to the cast irons impact toughness and wear resistance increase. The research is aimed at expanding the scope for new ADI applications in the industry.

Bainitic Cast Irons with Nanosized Particles

2020 ◽  
Vol 994 ◽  
pp. 104-111
Author(s):  
Julieta Atanasova Kaleicheva ◽  
Valentin Plamenov Mishev ◽  
Zdravka Kirilova Karaguiozova
Keyword(s):  
Titanium Nitride ◽  
Abrasive Wear ◽  
Mechanical Characteristics ◽  
Titanium Carbonitride ◽  
Wear Testing ◽  
Nanosized Particles ◽  
Cast Irons ◽  
X Ray ◽  
Bainitic Structure ◽  
Kinetics Of

In the present study austempered ductile irons (ADI) with lower bainitic structure are investigated. Nanosized particles (50nm) of titanium carbonitride + titanium nitride TiCN+TiN and titanium nitride TiN are added to the casting volume. The samples microstructure is studied by optical metallography and X-Ray analysis. The influence of the nanosized additives on the kinetics of the bainitic transformation and on the morphology of the bainitic structure is investigated. The abrasive wear testing, hardness measurements and impact strength are carried out. It is established that the presence of nanoadditives in the bainitic cast irons leads to the changes in their microstructure which increases their mechanical characteristics and abrasive wear resistance. The studied nanocomposite materials expand the potential for new ADI applications in the industry.

scholarly journals METHODS OF STUDYING THE STRUCTURE AND PROPERTIES OF MOUNTAIN BREEDS ON SAMPLES (QUICK REVIEW)

2018 ◽  
pp. 10-20
Author(s):  
A. A. Karabutov ◽  
E. B. Cherepetskaya ◽  
A. N. Kravcov ◽  
M. Arrigoni
Keyword(s):  
Internal Structure ◽  
Acoustic Microscopy ◽  
Laser Ultrasound ◽  
Structure And Properties ◽  
X Ray ◽  
Local Porosity ◽  
Non Destructive ◽  
Tomography Scanning ◽  
Destructive Methods ◽  
Scanning Electron

Some non-destructive methods for controlling the internal structure of rocks are described and examples of their use are given. Examples of the use of X-ray and neural tomography, scanning electron and acoustic microscopy are also given. It is shown that the method of laser-ultrasound struktroskopii is promising. Two examples of the use of the latter are given: measuring the local porosity of samples of geomaterials and monitoring changes in the internal structure as a result of electromagnetic exposure.

scholarly journals The The effect of iron on precipitation hardening in the Cu-Ni-Mn alloys

2021 ◽  
Vol 22 (3) ◽  
pp. 487-493
Author(s):  
O.V. Sukhova
Keyword(s):  
Precipitation Hardening ◽  
Annealing Temperature ◽  
Volume Fraction ◽  
Iron Oxidation ◽  
Quantitative Metallography ◽  
Structure And Properties ◽  
X Ray ◽  
Temperature Ranges ◽  
Fe Alloys ◽  
Scanning Electron

The peculiarities in the structure and properties formation of precipitation-hardened Сu–Ni–Mn–Fe alloys within the concentration range of Ni (19.3–21.0 %), Mn (19.5–20.5 %), Fe (0.6–2.7 %), Cu – balance (in wt. %) were investigated in this work. The methods of quantitative metallography, X-ray analysis, scanning electron microscopy, energy-dispersive spectroscopy and differential thermal analysis were applied. Two solid solutions based on a-Cu differing in composition and hardness were found in the structure of the cast Сu–Ni–Mn–Fe alloys. The temperature ranges of solutions’ formation were determined as (1010±10) °С and (890±10) °С, correspondingly. NiMn phase was also formed at (405±15) °С due to precipitation hardening. In the Сu–Ni–Mn–Fe alloys annealed at 500 and 900 °С for 60–750 hours, the volume fraction and size of NiMn precipitates increased with prolonging annealing time and lowering annealing temperature. As iron content was raised up to 2.7 wt. %, the density of NiMn precipitates increased, especially during first 60 hours of annealing at 900 °С. By adding iron, oxidation resistance was improved, but melting temperature and fluidity did not yield any significant change. Hardness of the Сu–Ni–Mn–Fe alloys with higher iron contents increased by 10 НRB on average. However, when test temperature was raised up to 400 °С, tensile strength decreased (by ~1.3 times) and elongation dropped markedly (by ~10 times).

Microstructure and Tempering Behaviour of 28Cr-2.5C-1W Cast Irons

2018 ◽  
Vol 283 ◽  
pp. 116-123
Author(s):  
Sasitorn Yeekew ◽  
Amporn Wiengmoon ◽  
Torranin Chairuangsri ◽  
John T.H. Pearce
Keyword(s):  
Carbide Precipitation ◽  
Air Cooling ◽  
Austenite Matrix ◽  
Secondary Carbide ◽  
Cast Irons ◽  
High Chromium ◽  
X Ray ◽  
Secondary Carbides ◽  
Cooling Phase ◽  
Scanning Electron

In this work, the effects of 1 wt.% tungsten addition and variation in tempering times on the microstructure and hardness of nominal 28 wt.%Cr high chromium irons were investigated. As-cast samples were destabilised at 1050 °C for 4 hours and then hardened by air cooling. Tempering after destabilisation was carried out at 450 °C for 2, 4 and 6 hours followed by air cooling. X-ray diffractometry, light microscopy and scanning electron microscopy were used to characterize the microstructures of the irons. The results show that the as-cast microstructure of the iron without W addition consisted of primary austenite dendrites with eutectic M7C3 and eutectic austenite partially transformed to martensite. The iron with 1 wt.%W addition contained primary M7C3 and eutectic M7C3 in an austenite matrix. Destabilisation treatment of the austenite matrix in both irons allowed precipitation of secondary carbides and transformation to martensite during air cooling. Phase transformation of eutectic M7C3 was also found in the iron with W addition. The formation of primary M7C3 in the 1 wt.%W iron increased the as-cast macro-hardness from 500 (no W) to 576 HV30. Destabilisation increased the macro-hardness up to 736 (no W) and 780 HV30 (1 wt.%W) since secondary carbide precipitation allowed austenite to transform to essentially martensitic matrices. At longer tempering times, the macro-hardness further increased up to about 820 HV30.

Metallography, Microanalysis & Corrosion of the Athlit Ram

2011 ◽  
Vol 1319 ◽  
Author(s):  
M. R. Notis ◽  
M. Hoban ◽  
D-N. Wang
Keyword(s):  
Electron Microscopy ◽  
Cell Walls ◽  
Optical Metallography ◽  
Metal Corrosion ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Matrix ◽  
Wood Analysis ◽  
Maritime Museum ◽  
Scanning Electron

ABSTRACTThe Athlit ram, a bronze warship ram from a 2nd Century BCE Roman-era galley, was found in 1980 off the coast of Israel at Athlit, and is now displayed at the National Maritime Museum, Haifa, Israel. It meant to fit on the prow of a medium-sized oared warship. This ram is the only known surviving example of this ancient naval weapon. Inside the bronze ram some of the ship’s wood is still preserved. We have recently studied a piece of the ram removed during early conservation. Remnant metal, corrosion products, and mineralized and pseudomorphed wood have all been found and examined by light optical metallography, x-ray diffraction, scanning electron microscopy, and microanalysis using energy dispersive x-ray mapping. The main corrosion product on the Athlit Ram is identified as covellite (CuS), and the entrained material is pseudomorphed cedar wood. Analysis indicates the lumen to be replaced by calcium carbonate and the cell walls to be replaced by covellite, consistent with the matrix.

Synthesis, Structure and Properties of Super Fine LiMn2O4

2010 ◽  
Vol 177 ◽  
pp. 9-11 ◽  
Author(s):  
Jie Song ◽  
Bing Xu ◽  
De Xin Huang ◽  
Cai Xia Li ◽  
Qiang Li
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Particle Size ◽  
Electrode Material ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
Mechanochemical Method ◽  
X Ray ◽  
Size And Morphology ◽  
Scanning Electron

In this paper, super fine LiMn2O4 powder was synthesized by mechanochemical method starting from Li2CO3 and Mn2O3. The structure, size and morphology of LiMn2O4 were explored with X-ray diffraction and scanning electron microscopy (SEM). The electrochemical properties of LiMn2O4 were studied in 2 mol/L (NH4)2SO4 solution. The result showed that pure spinel LiMn204 powder was prepared after 8h grinding with 3.0KW of power and the particle size was about 1µm. Cyclic vohammetry curve indicate LiMn2O4 electrode material has better capacitive performances.

scholarly journals Microstructure of Dental Amalgams Containing High and Low Copper Contents

1977 ◽  
Vol 56 (12) ◽  
pp. 1481-1487 ◽  
Author(s):  
Manohar L. Malhotra ◽  
Kamal Asgar
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
20Th Century ◽  
Energy Dispersive Spectroscopy ◽  
Optical Metallography ◽  
Dental Alloys ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dental Amalgams ◽  
Scanning Electron

Microstructure of commercial dental alloys and their amalgams were studied primarily by x-ray diffraction, optical metallography, scanning electron microscopy, and x-ray energy dispersive spectroscopy. X-ray diffraction revealed more phases than normally reported in these materials. Presence of new phases was discussed and their formation mechanism understood. Some phases having interacting 2θ° values with others were properly identified. Both new and conventional dental alloys and their amalgams, namely Tytin, Sybraloy, Dispersalloy, Kerr Spheraloy, Caulk Spherical, Shofu Spherical, and Caulk 20th Century Microcut were used to complete the investigation.

The Structural and Morphological Properties of Nanosized Nd(1-x)Sr(x)MnO3 (x = 0; 0.5; 1) Manganite

2020 ◽  
Vol 855 ◽  
pp. 78-83
Author(s):  
Amilita Medisa Dharmayanti ◽  
Qoimatul Mustaghfiroh ◽  
Dicky Rezky Munazat ◽  
Dhawud Sabilur Razaq ◽  
Budhy Kurniawan ◽  
...  
Keyword(s):  
Sol Gel ◽  
Morphological Properties ◽  
Nanosized Particles ◽  
Orthorhombic Structure ◽  
X Ray ◽  
Morphological Behavior ◽  
A Site ◽  
Modify Structure ◽  
Scanning Electron ◽  
Shape And Size

A set of nanoparticles NdSrMnO3 has been prepared base on sol-gel method. On A site, the nanoparticles were modified by substitution among Nd and Sr. The effect of substitution on A site of sample to the structural and morphological were entirely examined by mean of X-Ray Diffractometer (XRD) and Scanning Electron Microscopy (SEM). From XRD result, it is found that all the sample under investigated show orthorhombic structure indicating that A site substitution does not modify structure. On the other hand, some morphological behavior has been proposed as A site is substituted. The shape and size of sample are significantly different, resulting A site substitution succeed to influenced morphology of nanosized particles.

Study of Plasma Cladding Ni-Based Compound Powder Layers on Q235 Steel

2012 ◽  
Vol 174-177 ◽  
pp. 219-222
Author(s):  
Zhi Xin Wang ◽  
Li Qian ◽  
Wei Tie Yang
Keyword(s):  
Wear Resistance ◽  
Composite Coating ◽  
X Ray Diffraction ◽  
Microstructure Formation ◽  
X Ray ◽  
Q235 Steel ◽  
Microhardness Distribution ◽  
Resistance Increase ◽  
Plasma Cladding ◽  
Scanning Electron

By plasma cladding technology, the Ni60B/TiC composite coating metallurgically bonded to Q235 steel were prepared using Ni-based alloy and TiC powders. The microstructure formation mechanism of the clad layers was investigated by scanning electron microscopy (SEM) and X-ray Diffraction (XRD). The microhardness distribution and wear resistance of the specimens were tested. The results show that metallurgical combination is achieved between coating and substrate, the microstructure of composite coating is composed of dendrite γ-Ni, α-Fe, added TiC and FeNi. The hardness and wear resistance of composite coating have relationship with TiC particles content and TiC particles distribution. The hardness and wear resistance increase with the increase of TiC particles content.

Structure and Properties of Bi0.5Na0.5TiO3-BaTiO3 Compound Ceramics

2011 ◽  
Vol 411 ◽  
pp. 503-507
Author(s):  
Xiao Juan Li ◽  
Zeng Zhe Xi ◽  
Wei Long ◽  
Zhi Gang Zhang ◽  
Jia Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Dielectric Properties ◽  
Diffraction Analysis ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
Oriented Growth ◽  
X Ray ◽  
Scanning Electron

The Bi0.5Na0.5TiO3-xwt%BaTiO3 compound ceramics were prepared. The influence of different BaTiO3 content on structure was evaluated by scanning electron microscopy and X-ray diffraction analysis. The results show oriented is induced by plate-like BaTiO3 template. Signficant improvement of the piezoelectric (d33 = 112 pC/N) and dielectric properties ( max ≈ 5500) was observed. The improvement was attested to the apparent alignment of the BaTiO3 templates and grain oriented growth.

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