Plasma FIB Spinmill for Al alloy Sample Preparation

2021 ◽  
Author(s):  
Changrun CAI
Keyword(s):  
Sample Preparation ◽  
Al Alloy ◽  
Alloy Sample

Diffraction study on bainite of Cu-Al alloy

1990 ◽  
Vol 48 (4) ◽  
pp. 1006-1007
Author(s):  
Delu Liu ◽  
T. Ko
Keyword(s):  
Diffraction Study ◽  
Parent Phase ◽  
Al Alloy ◽  
Alloy Sample ◽  
Bright Field Image ◽  
Hexagonal System ◽  
Iced Brine ◽  
Diffraction Patterns ◽  
Zone Pattern ◽  
Stacking Structure

Structure of bainite in Cu-Al and Cu-Zn-Al alloys has been reported as 3R, 9R or 18R long period stacking structure (LPS) by X-ray and electron diffraction studies. In the present work, a Cu-25.5 (at)% Al alloy sample was heated at 900°C for 2 h then isothermally held at 450°C for 60 s before quenching into iced brine. FIG.1 shows a TEM bright field image of bainite plates (marked B) grown from grain boundary. The parent phase ( with DO3 structure ) has transformed to martensite (marked M ) during cooling from 450° C to 0°C. Both bainite and martensite plates have dense striations inside.Careful diffraction study on a JEOL 2000FX TEM with accelerating voltage 200 KV revealed (FIG.2) that the diffraction patterns contai_ning the same zone axis [001] ( hexagonal index ) or [111]c ( cubic index ) are from a bainite plate with obtuse V-shape. They are indexed as [010], [140], [130], [120], [230], [340] and [110] zone pattern for hexagonal system respectively.

scholarly journals Обнаружение новой фазы типа B1 в монокристаллах магнитомягких сплавов Fe-Al и Fe-Ga

2019 ◽  
Vol 61 (11) ◽  
pp. 2000 ◽  
Author(s):  
Ю.П. Черненков ◽  
Н.В. Ершов ◽  
В.А. Лукшина
Keyword(s):  
Volume Fraction ◽  
Ferromagnetic State ◽  
Aluminum Concentration ◽  
Al Alloy ◽  
Alloy Sample ◽  
Face Centered Cubic ◽  
Bcc Lattice ◽  
Fcc Lattice ◽  
Face Centered ◽  
Fcc Phase

AbstractThe atomic structure of Fe–Al (7 and 9 at % Al) and Fe–Ga (18 at % Ga) alloys is studied by X‑ray diffraction using a laboratory four-circle diffractometer. After refining annealing, single-crystal alloy samples were annealed in the ferromagnetic state ( T < T _C). One sample of the Fe–18 at % Ga alloy, after short holding in the paramagnetic state ( T > T _C), was quenched in room temperature water. Earlier, the authors reported on the peculiarities of the ordering of alloying atoms in B 2 and D 0_3 phase structures in quenched and annealed samples of these alloys. Here, we present and discuss the results of our observations in these alloys of a new phase with a face-centered cubic (fcc) lattice ( B 1-type structure with NaCl prototype and unit cell parameter ~5.2 nm). The fcc phase appears in the Fe–Al alloy as the aluminum concentration increases from 7 to 9 at %; it is observed in the Fe–18 at % Ga alloy, and its volume fraction increases after annealing in the ferromagnetic state in comparison with a quenched alloy sample. In these alloys (9 at % Al) and (18 at % Ga), different ways of embedding fcc crystals in the bcc phase of single crystals are realized; i.e., the axes of the fcc lattice are directed in four different ways relative to the axes of the bcc lattice.

Simulation of Mold Filling and Solidification on Gravity Casting of Al-Si Alloy (A357)

2008 ◽  
Vol 575-578 ◽  
pp. 1204-1209
Author(s):  
Guo Fa Mi ◽  
Heng Tao Zhao ◽  
Kuang Fei Wang ◽  
Zhi An Xu ◽  
Ji Tai Niu
Keyword(s):  
Solidification Process ◽  
Mold Filling ◽  
Simulation Software ◽  
Temperature Fields ◽  
Al Alloy ◽  
Alloy Sample ◽  
Gravity Casting ◽  
Solidification Processes ◽  
Feeding Process ◽  
Filling And Solidification

The temperature at specific positions was measured by multi-channel data acquisition system in order to understand the solidification and feeding process of the sample. The Olympus metallurgical microscope was used to observe the macrostructure of the casting and analyze the freezing mechanism. The mold filling and solidification processes of the Al-alloy sample were studied by using the commercialized simulation software Z-Cast. And the simulated result was compared with the results of practical pouring test. When preheat temperature of mold is low, the pouring temperature should be higher in order to ensure completely filling of mold. As a result the solidification of sample could be feeding effectively, and the shrinkage on the upper end of sample could be eliminated. It is shown that the casting simulation software Z-CAST can be used to simulate the filling and solidification process of gravity cast Al alloy and can provide exact flow fields and temperature fields thus can predict cast defects and their positions.

scholarly journals Corrosion of the Welded Aluminium Alloy in 0.5 M NaCl Solution. Part 1: Specificity of Development

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2053 ◽  
Author(s):  
Andrey Gnedenkov ◽  
Sergey Sinebryukhov ◽  
Dmitry Mashtalyar ◽  
Igor Vyaliy ◽  
Vladimir Egorkin ◽  
...  
Keyword(s):  
Aluminium Alloy ◽  
Process Development ◽  
Morphological Structure ◽  
Weld Interface ◽  
Al Alloy ◽  
Alloy Sample ◽  
Nacl Solution ◽  
Corrosive Media ◽  
The Stability ◽  
Electrode Technique

This work consists of two parts. In the first part, the kinetics and mechanism of corrosion on the surface of the welded joint area of the aircraft 1579 aluminium alloy have been studied using SVET (scanning vibrating electrode technique) and SIET (scanning ion-selective electrode technique) in 0.5 M NaCl. The results have revealed the corrosion process development within the weld interface due to the presence of microdefects in the morphological structure. Features of the 1579 Al alloy corrosion have also been investigated through immersion experiments, quantitative analysis of dissolved alloying elements by means of atomic absorption spectroscopy, and corrosion products characterization using XRD (X-ray diffraction) analysis. The presence of Mg as an alloying element in the 1579 Al alloy sufficiently increases the bulk pH values as a result of the intensive dissolution of Mg. These factors accelerate the corrosion activity of the studied material in the 0.5 M NaCl solution. Corrosion evolution analysis of the 1579 Al alloy sample showed the importance of the coating formation to protect this alloy against corrosion and to increase the stability of this system in the corrosive media.

scholarly journals A versatile cryo-transfer system, connecting cryogenic focused ion beam sample preparation to atom probe microscopy

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245555
Author(s):  
Chandra Macauley ◽  
Martina Heller ◽  
Alexander Rausch ◽  
Frank Kümmel ◽  
Peter Felfer
Keyword(s):  
Sample Preparation ◽  
Focused Ion Beam ◽  
Environmental Control ◽  
Structural Information ◽  
Morphological Changes ◽  
Ion Beam ◽  
Atom Probe ◽  
Al Alloy ◽  
Transfer System ◽  
Ambient Conditions

Atom probe tomography (APT) is a powerful technique to obtain 3D chemical and structural information, however the ‘standard’ atom probe experimental workflow involves transfer of specimens at ambient conditions. The ability to transfer air- or thermally-sensitive samples between instruments while maintaining environmental control is critical to prevent chemical or morphological changes prior to analysis for a variety of interesting sample materials. In this article, we describe a versatile transfer system that enables cryogenic- or room-temperature transfer of specimens in vacuum or atmospheric conditions between sample preparation stations, a focused ion beam system (Zeiss Crossbeam 540) and a widely used commercial atom probe system (CAMECA LEAP 4000X HR). As an example for the use of this transfer system, we present atom probe data of gallium- (Ga)-free grain boundaries in an aluminum (Al) alloy specimen prepared with a Ga-based FIB.

scholarly journals Fabrication of Self-Cleaning Superhydrophobic Surfaces with Improved Corrosion Resistance on 6061 Aluminum Alloys

Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 159 ◽  
Author(s):  
Xiaojuan Dong ◽  
Jianbing Meng ◽  
Yizhong Hu ◽  
Xiuting Wei ◽  
Xiaosheng Luan ◽  
...  
Keyword(s):  
Contact Angle ◽  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Superhydrophobic Surface ◽  
Al Alloy ◽  
Alloy Sample ◽  
Sliding Angle ◽  
Water Contact ◽  
Self Cleaning

Aluminum alloys are widely used, but they are prone to contamination or damage under harsh working environments. In this paper, a self-cleaning superhydrophobic aluminum alloy surface with good corrosion resistance was successfully fabricated via the combination of sand peening and electrochemical oxidation, and it was subsequently covered with a fluoroalkylsilane (FAS) film. The surface morphology, surface wettability, and corrosion resistance were investigated using a scanning electron microscope (SEM), an optical contact angle measurement, and an electrochemical workstation. The results show that binary rough structures and an FAS film with a low surface energy on the Al alloy surfaces confer good superhydrophobicity with a water contact angle of 167.5 ± 1.1° and a sliding angle of 2.5 ± 0.7°. Meanwhile, the potentiodynamic polarization curve shows that the corrosion potential has a positively shifted trend, and the corrosion current density decreases by three orders of magnitude compared with that of the original aluminum alloy sample. In addition, the chemical stability of the as-prepared superhydrophobic surface was evaluated by dripping test using solutions with different pH values for different immersion time. It indicates that the superhydrophobic surface could provide long-term corrosion protection for aluminum alloys. Consequently, the as-prepared superhydrophobic surface has excellent contamination resistance and self-cleaning efficacy, which are important for practical applications.

Study on axial changes of As-cast structures of Al-alloy sample treated by the novel SPMF technique

2000 ◽  
Vol 43 (4) ◽  
pp. 377-380 ◽  
Author(s):  
Z.I Bingtao ◽  
B.A Qixian ◽  
C.U.I Jianzhong ◽  
X.U Guangming
Keyword(s):  
Al Alloy ◽  
Alloy Sample ◽  
The Novel

Improving crack resistivity in Al alloy pressure vessels by FSW

2016 ◽  
Vol 79 (2) ◽  
pp. 54-58
Author(s):  
A.W.A. Lenin ◽  
P. Nagaraj ◽  
G. Lincy
Keyword(s):  
High Strength ◽  
Light Metal ◽  
Pressure Vessels ◽  
Al Alloy ◽  
Alloy Sample ◽  
External Interference ◽  
Manufacturing Defects ◽  
Friction Stir ◽  
Significant Research ◽  
Design Selection

Purpose: Fuel or oil transmission pipelines are made with light metal alloys to preventcorrosion and to provide a better safety record. This is achieved by the combinationof perfect design, selection of materials and functioning practices. However, like anyengineering structure, these lines also fail occasionally. Major cases of such failure it inducesdue to external interference or corrosion or due to manufacturing defects; so such of defectsif they were detected before failure and that can be treated to avoid failure or the life timecan be improved.Design/methodology/approach: In this study an aluminum alloy sample with microcrack was treated with FSW process with ZN powder. And studies were carried out againstboth treated and untreated samples with cracks.Findings: From the studies it is clear that FSW treatment over surfaces will reduces thecrack initiation in light metal alloy structures. The process can be done before or afterinstallation.Research limitations/implications: The results were recorded and suggested FSW as abest process for crack treatment in Al alloys. Especially in pressure lines or pressure vessels.Originality/value: Friction stir welding (FSW) is a solid-state metal joining process. Thisis energy efficient, ecofriendly, and versatile light metal joining technique. In particular,high-strength aerospace aluminum alloys can be welded by using this technique. This willproduces high harden joints in light metals as just like conventional arc welding techniques.It is considered as the most significant research development in light metal joining.

scholarly journals Energy Density Effect of Laser Alloyed TiB2/TiC/Al Composite Coatings on LMZ/HAZ, Mechanical and Corrosion Properties

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 411
Author(s):  
Dunja Ravnikar ◽  
Uroš Trdan ◽  
Aleš Nagode ◽  
Roman Šturm
Keyword(s):  
Laser Energy ◽  
Composite Coatings ◽  
Corrosion Current ◽  
Al Alloy ◽  
Alloy Sample ◽  
Corrosion Properties ◽  
Cyclic Polarization ◽  
Al Composite ◽  
General Improvement ◽  
High Fraction

In the present work, TiC/TiB2/Al composite coatings were synthesized onto a precipitation hardened AlSi1MgMn alloy by laser surface alloying (LSA), using 13.3 J/mm2 and 20 J/mm2 laser energy densities. Microstructure evaluation, microhardness, wear and corrosion performance were investigated and compared with the untreated/substrate Al alloy sample. The results confirmed sound, compact, crackles composite coating of low porosity, with a proper surface/substrate interface. Microstructural analyses revealed the formation of extremely fine nano-precipitates, ranging from of 50–250 nm in the laser melted (LMZ) and large precipitates, accompanied with grain coarsening in the heat-affected zone (HAZ), due to the substrate overheating during the LSA process. Nonetheless, both coatings achieved higher microhardness, with almost 7-times higher wear resistance than the untreated sample as a consequence of high fraction volume of hard, wear resistant TiB2 and TiC phases inside the composite coatings. Further, cyclic polarization results in 0.5 M NaCl aqueous solution confirmed general improvement of corrosion resistance after LSA processed samples, with reduced corrosion current by more than a factor of 9, enhanced passivation/repassivation ability and complete prohibition of crystallographic pitting, which was detected with the untreated Al alloy.

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