scholarly journals Enhanced Fluidity of ZL205A Alloy with the Combined Addition of Al–Ti–C and La

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6169
Author(s):  
Guowei Zhang ◽  
Zhaojie Wang ◽  
Jingwei Niu ◽  
Hong Xu ◽  
Xiaoyan Ren
Keyword(s):  
Grain Size ◽  
Heterogeneous Nucleation ◽  
Base Alloy ◽  
Microstructure Characterization ◽  
Solidification Range ◽  
Zl205a Alloy ◽  
Role Based ◽  
Fluidity Test ◽  
Number Of Particles

The effects of Al–Ti–C and La on the fluidity of a ZL205A alloy after separate and combined addition were studied by conducting a fluidity test. The fluidity of the ZL205A alloy first increased and then decreased with the increasing addition of Al–Ti–C and La; it peaked at 0.3% and 0.1% for Al–Ti–C and La, respectively. The combined addition of Al–Ti–C and La led to better fluidity, which increased by 74% compared with the base alloy. The affecting mechanism was clarified through microstructure characterization and a DSC test. The heterogeneous nucleation aided by Al–Ti–C and La, the number of particles in the melt, and the evolution of the solidification range all played a role. Based on the evolution of the fluidity and grain size, the optimal levels of Al–Ti–C and La leading to both high fluidity and small grain size were identified.

Microstructure and Tensile Property of Zn-Al Alloy Reinforced with Titanium Produced by Electrolysis

2009 ◽  
Vol 79-82 ◽  
pp. 1415-1418 ◽  
Author(s):  
Shu Qing Yan ◽  
Jing Pei Xie ◽  
Wen Yan Wang ◽  
Ji Wen Li
Keyword(s):  
Grain Size ◽  
Tensile Property ◽  
Heterogeneous Nucleation ◽  
Titanium Content ◽  
Small Dimension ◽  
Al Alloy ◽  
Exotic Particles ◽  
Titanium Aluminum ◽  
High Dispersity

In this study, some low-titanium aluminum alloys produced by electrolysis were prepared and the effect of various titanium contents on microstructure and tensile property of Zn-Al alloy was investigated. The test results showed that addition of titanium by electrolysis is an effective way to refine the grain size of Zn-Al alloy. As the titanium content is 0.04 wt%, the grain size becomes to be a minimum value and the tensile property of the alloy reaches to the maximum. Electrolysis showed that titanium atoms are to be some inherent particles in low-titanium aluminum alloy. These titanium atoms enter into the aluminum melt liquid and spread to the whole melt rapidly under stirring action of electromagnetic field of the electric current. The heterogeneous phase nuclei are high melting TiC and TiAl3 particles formed from in-situ precipitating trace C and Ti during cooling process. These in-situ precipitating heterogeneous nucleation sites with small dimension, high dispersity, cleaning interface and fine soakage with melt, have better capacity of heterogeneous nucleation than of exotic particles. It may inhibit grain growth faster and more effective in pinning dislocations, grain boundaries or sub-boundaries.

Experimental investigation of electrodeposited Ni-Al2O3/ZrO2 nano composite on HSLA ASTM A860 alloy

2021 ◽  
Author(s):  
Chandrasekhara Sastry Chebiyyam ◽  
Pradeep N ◽  
Shaik AM ◽  
Hafeezur Rahman A ◽  
Sandeep Patil
Keyword(s):  
Grain Size ◽  
Corrosion Resistance ◽  
Composite Coating ◽  
Base Alloy ◽  
Composite Coatings ◽  
Nano Particles ◽  
Alloy Sample ◽  
Nano Composite ◽  
Nano Coating ◽  
Nano Composite Coating

Abstract Nano composite coatings on HSLA ASTM A860 alloy, adds to the barrier efficacy by increase in the microhardness, wear and corrosion resistance of the substrate material. Additionally, reduction of delamination of the nano composite coating sample is ascertained. Ball milling is availed to curtail the coating samples (Al2O3/ZrO2) to nano size, for forming a electrodeposited product on the substrate layer. The curtailment in grain size was ascertained to be 17.62% in Ni-Al2O3/ZrO2 nano composite coating. During the deposition process, due to the presence of Al2O3/ZrO2 nano particles an increase in cathode efficiency is ascertained. An XRD analysis of the nano composite coating indicates a curtailment in grain size along with increase in the nucleation sites causing a surge in the growth of nano coating layer. In correlation to uncoated HSLA ASTM A36 alloy sample, a surge in compressive residual stress by 47.14%, reduction of waviness by 32.14% (AFM analysis), upsurge in microhardness by 67.77% is ascertained in Ni-Al2O3/ZrO2 nano composite coating. Furthermore, in nano coated Ni-Al2O3/ZrO2 composite a reduction is observed pertaining to weight loss and friction coefficients by 27.44% and 13% in correlation to plain uncoated alloy respectively. A morphology analysis after nano coating indicates, Ni-Al2O3/ZrO2 particles occupy the areas of micro holes, reducing the wide gaps and crevice points inside the matrix of the substrate, enacting as a physical barrier to upsurge the corrosion resistance by 67.72% in correlation to HSLA ASTM A860 base alloy.

scholarly journals Myrmekite and strain weakening in granitoid mylonites

2018 ◽  
Author(s):  
Alberto Ceccato ◽  
Luca Menegon ◽  
Giorgio Pennacchioni ◽  
Luiz Fernando Grafulha Morales
Keyword(s):  
Grain Size ◽  
Heterogeneous Nucleation ◽  
Eastern Alps ◽  
Grain Boundary Sliding ◽  
Dislocation Creep ◽  
Diffusion Creep ◽  
Phase Mixing ◽  
Fine Grained ◽  
Fine Grain ◽  
Creep Cavitation

Abstract. At mid-crustal conditions, deformation of feldspar is mainly accomplished by a combination of fracturing, dissolution/precipitation and reaction-weakening mechanisms. In particular, K-feldspar is reaction-weakened by formation of strain-induced myrmekite – a fine-grained symplectite of plagioclase and quartz. Here we investigate with EBSD the microstructure of a granodiorite mylonite, developed at 420–460 °C during cooling of the Rieserferner pluton (Eastern Alps), to assess the microstructural processes and the role of weakening associated with myrmekite development. Our analysis shows that the crystallographic orientation of the plagioclase of pristine myrmekite was controlled by that of the replaced K-feldspar. Myrmekite nucleation resulted in both grain size reduction and ordered phase mixing by heterogeneous nucleation of quartz and plagioclase. The fine grain size of sheared myrmekite promoted grain size-sensitive creep mechanisms including fluid-assisted grain boundary sliding in plagioclase, coupled with heterogeneous nucleation of quartz within creep cavitation pores. Flow laws calculated for monomineralic quartz, feldspar, and quartz + plagioclase aggregates (sheared myrmekite), show that during mylonitization at 450 °C, grain-size-sensitive creep in sheared myrmekite accommodated strain rates several orders of magnitude higher than monomineralic quartz layers deforming by dislocation creep. Therefore, diffusion creep and grain size-sensitive processes contributed significantly to bulk rock weakening during mylonitization. Our results have implications for modelling the rheology of the mid-upper continental (felsic) crust.

Apfim Investigation of Segregation in a Nickel Base Alloy

1998 ◽  
Vol 4 (S2) ◽  
pp. 118-119
Author(s):  
M. Thuvander ◽  
K. Stiller
Keyword(s):  
Grain Size ◽  
Base Alloy ◽  
Atom Probe ◽  
Model Alloy ◽  
Probe Field ◽  
Inconel 600 ◽  
Carbon And Nitrogen ◽  
Heat Treated ◽  
Nickel Base ◽  
Boron Carbon

Segregation of boron, carbon and nitrogen to grain boundaries in a nickel based model alloy has been investigated using atom probe field ion microscopy (APFIM). The material corresponds to a commercial alloy (Inconel 600), but contains lower levels of alloy additives and impurities. The major composition was Ni-16Cr-10Fe (wt.%). The alloy was solution annealed at 950°C for 10 min, which resulted in a grain size of 20 μ. Subsequently heat treatments for 1 h at temperatures of 550°C, 600°C and 700°C were applied. TEM investigation showed that the heat treatment at 700°C resulted in precipitation of intergranular chromium-rich carbides. The other temperatures were obviously too low and the aging times too short to cause precipitation, since carbides were not observed in the materials heat treated at 550°C and 600°C.As the grain size was about 100 times larger than the accessible depth of APFIM analysis (≃200 nm), much care had to be taken in preparing samples containing a grain boundary close to the tip apex.

Refinement Effect and Mechanism of AZ31 Magnesium Alloy by Electromagnetic Stirring under the Effect of Grain-Refiner

2013 ◽  
Vol 631-632 ◽  
pp. 556-561 ◽  
Author(s):  
Sheng Yuan Gao ◽  
Shi Lian Qu ◽  
Yue Yuan ◽  
Bao Qin Fu
Keyword(s):  
Grain Size ◽  
Magnesium Alloy ◽  
Heterogeneous Nucleation ◽  
Holding Time ◽  
Electromagnetic Stirring ◽  
Az31 Magnesium Alloy ◽  
Grain Refiner ◽  
Nucleation Sites ◽  
Continuously Cast ◽  
Refinement Effect

The effects of electromagnetic stirring and Al4C3grain refiner on the grain refinement of semi-continuously cast AZ31 magnesium alloy were discussed in this investigation. The results indicate that electromagnetic stirring has effective refining effect on the grain size of AZ31 magnesium alloy under the effect of Al4C3grain refiner. Electromagnetic stirring can “activate” the Al4C3particles, resulting in more heterogeneous nucleation sites for the primary α-Mg grains. But, longer holding time can “inactivate” the Al4C3particles, and the optimal experimental holding time is 60 min in the present investigation. The activated rate of the electromagnetic under the experimental condition ρ2=1.65%.

Embrittlement of Precipitation Hardenable Nickel-Base Alloys by Oxygen

1971 ◽  
Vol 93 (2) ◽  
pp. 225-230 ◽  
Author(s):  
M. Prager ◽  
G. Sines
Keyword(s):  
Grain Size ◽  
Surface Energy ◽  
Base Alloy ◽  
Tensile Tests ◽  
Inert Atmosphere ◽  
Nickel Base Alloy ◽  
Gamma Prime ◽  
Tensile Fractures ◽  
Nickel Base ◽  
Short Time

A study was made of the embrittling effects of oxygen on Rene´ 41, a nickel-base alloy hardened by precipitation of gamma prime. In short time tensile tests in air it was found that from 750 to 900 deg C oxygen promoted initiation and rapid propagation of intergranular cracks, while in the absence of oxygen, tensile fractures were transgranular and ductility was much improved. Sensitivity to embrittlement by oxygen decreases with coarsening of gamma prime. When gamma prime is hyperfine, probably less than 100 Å, embrittlement is greatest and follows the predictions of a Petch-Stroh model for the initiation of cracks ahead of pile-ups of dislocations. In accordance with the model, the ductility of Rene´ 41 increased in proportion of the reciprocal of the square roo of grain size. Calculated on the basis of the model, the surface energy of Rene´ 41 in air was 400 ergs/cm2, considerably lower than would be expected for an alloy of nickel in an inert atmosphere.

Effect of A-EMS above Liquidus Temperature on Structure Refinement of Al-11%Zn-3%Mg-1%Cu-0.13%Zr Alloy

2017 ◽  
Vol 898 ◽  
pp. 24-28 ◽  
Author(s):  
Tian Yang Guan ◽  
Zhi Feng Zhang ◽  
Yue Long Bai ◽  
Ping Wang
Keyword(s):  
Grain Size ◽  
Heterogeneous Nucleation ◽  
Liquidus Temperature ◽  
Structure Refinement ◽  
Electromagnetic Stirring ◽  
Homogeneous Structure ◽  
Grain Refining ◽  
High Quality ◽  
Instantaneous Nucleation ◽  
Zr Alloy

The application of Annular Electromagnetic Stirring (A-EMS) for production of high-quality slurry has been examined. Al-11%Zn-3%Mg-1%Cu-0.13%Zr alloy was used to investigate the effect of A-EMS at various temperatures above liquidus on structure refinement. The results indicate that the grain size was reduced greatly and the homogeneous structure was achieved. Instead of the case in tradition, the nucleation particles gradually formed and the enhanced grain refining efficiency can be mainly attributed to an instantaneous nucleation of numerous heterogeneous nucleation of Al3Zr in the superheating melt under A-EMS.

scholarly journals Heterogeneous Nucleation by Aggregates of Particles

1960 ◽  
Vol 13 (3) ◽  
pp. 584 ◽  
Author(s):  
RB Head ◽  
KL Sutherland
Keyword(s):  
Heterogeneous Nucleation ◽  
Fine Particles ◽  
Flat Surface ◽  
Phase Point ◽  
General Effect ◽  
Point Contacts ◽  
Active Particles ◽  
Line Contacts ◽  
New Phase ◽  
Number Of Particles

The induction of a new phase by fine particles of a nucleating substance is complicated not only by variation in sizes but also by aggregation. The general effect of aggregation is to decrease the total number of particles but to reduce the supercooling (or supersaturation) necessary for growth of a new phase. Point contacts appear to be more fruitful than do line contacts, although both may be able to cause a substance to be more active than a large flat surface of the substrate. If the contact between particles is not a specially favoured position for nucleation, the aerosol as a whole appears to contain a higher proportion of active particles because of the persistence of initially active particles and the loss of less active ones.

scholarly journals Size Distribution of Particulate Matter in Indoor Environment During Nanomaterial Paint Application

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Barbora ŠVÉDOVÁ ◽  
Marek KUCBEL ◽  
Helena RACLAVSKÁ ◽  
Konstantin RACLAVSKÝ ◽  
Pavel KANTOR
Keyword(s):  
Grain Size ◽  
Particulate Matter ◽  
Size Distribution ◽  
Mass Concentration ◽  
Indoor Environment ◽  
Cascade Impactor ◽  
Size Class ◽  
Aerodynamic Diameter ◽  
Particle Mass Concentration ◽  
Number Of Particles

Due to the increasing production and development of nanoparticles, it has become necessary to control the exposure to ultrafineparticles (aerodynamic diameter < 0.1 μm) when handling nanopaints. The paper deals with the number and mass distributionof particulate matter (PM) in an indoor environment before, during and after the application of paint Protectam FN containingtitanium nanoparticles. The size distribution determination was performed by the electrical low-pressure cascade impactor (ELPI+)in the range from 0.006 μm to 9.93 μm. The highest number of particles was observed in the range from 0.006 to 0.0175 μm. Theparticulate mass concentration ranging from 0.0175 to 0.0307 μm did not represent more than 0.5% of the sum of PM10 during theindividual measurements. The particle mass concentration increased in the range of 0.0175 to 0.0307 μm, after application of thecoating nanopaint Protectam FN, but it was observed that the total number of particles has decreased. During the days followingthe application of the nanopaint, the mass concentration in this grain size class was significantly reduced.

scholarly journals Myrmekite and strain weakening in granitoid mylonites

Solid Earth ◽  
2018 ◽  
Vol 9 (6) ◽  
pp. 1399-1419 ◽  
Author(s):  
Alberto Ceccato ◽  
Luca Menegon ◽  
Giorgio Pennacchioni ◽  
Luiz Fernando Grafulha Morales
Keyword(s):  
Grain Size ◽  
Heterogeneous Nucleation ◽  
Eastern Alps ◽  
Grain Boundary Sliding ◽  
Dislocation Creep ◽  
Diffusion Creep ◽  
Electron Backscattered Diffraction ◽  
Fine Grained ◽  
Fine Grain ◽  
Creep Cavitation

Abstract. At mid-crustal conditions, deformation of feldspar is mainly accommodated by a combination of fracturing, dissolution–precipitation, and reaction-weakening mechanisms. In particular, K-feldspar is reaction-weakened by the formation of strain-induced myrmekite – a fine-grained symplectite of plagioclase and quartz. Here we use electron backscattered diffraction to (i) investigate the microstructure of a granodiorite mylonite, developed at  ∼ 450 °C during cooling of the Rieserferner pluton (Eastern Alps); and (ii) assess the microstructural processes and the weakening associated with myrmekite development. Our analysis shows that the crystallographic orientation of plagioclase in pristine myrmekite was controlled by that of the replaced K-feldspar. Myrmekite nucleation resulted in both grain-size reduction and anti-clustered phase mixing by heterogeneous nucleation of quartz and plagioclase. The fine grain size of sheared myrmekite promoted grain-size-sensitive creep mechanisms including fluid-assisted grain boundary sliding in plagioclase, coupled with heterogeneous nucleation of quartz within creep cavitation pores. Flow laws, calculated for monomineralic quartz, feldspar, and quartz + plagioclase aggregates (sheared myrmekite) during deformation at 450 °C, show that grain-size-sensitive creep in sheared myrmekite accommodated strain rates several orders of magnitude higher than monomineralic quartz layers deforming by dislocation creep. Therefore, diffusion creep and grain-size-sensitive processes contributed significantly to bulk rock weakening during mylonitization. Our results have implications for modelling the rheology of the felsic middle crust.

Sign in / Sign up

Export Citation Format

Share Document