Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Effect of Cooling Rate on Morphology of TiAl3 Particles in Al-4Ti Master Alloy.

ABSTRACT: The Al-4Ti master alloy was fabricated by aluminum (Al) and sponge titanium particle in a resistance furnace at different cooling rates. This work aims to investigate the relationship between the cooling rate and morphology of TiAl3. The microstructure and composition of master alloys at different cooling rates were characterized and analyzed by optical microscopy (OM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and SEM with energy dispersive spectroscopy (EDS). The results showed that various morphologies of TiAl3 particles in the Al-4Ti master alloy could be acquired at different cooling rates. Petal-like, blocky, and flake-like TiAl3 particles in the Al-4Ti master alloy were respectively acquired at the cooling rates of 3.36 K/s, 2.57 K/s, and 0.31 K/s. It was also found that the morphology of TiAl3 particles in the prepared master alloy changed from petal-like to blocky, then finally to flake-like, with the decrease of cooling rate. In addition, the morphology of the TiAl3 particles has no effect on the phase inversion temperature of Al-4Ti master alloy.

SUBMITTER: Zhao J

PROVIDER: S-EPMC5503408 | biostudies-other | 2017 Feb

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

Effect of Al-5Ti-C Master Alloy on the Microstructure and Mechanical Properties of Hypereutectic Al-20%Si Alloy.

Project description:Al-5Ti-C master alloy was prepared and used to modify hypereutectic Al-20%Si alloy. The microstructure evolution and mechanical properties of hypereutectic Al-20%Si alloy with Al-5Ti-C master alloy additions (0, 0.4, 0.6, 1.0, 1.6 and 2.0 wt%) were investigated. The results show that, Al-5Ti-C master alloy (0.6 wt%, 10 min) can significantly refine both eutectic and primary Si of hypereutectic Al-20%Si alloy. The morphology of the primary Si crystals was significantly refined from a coarse polygonal and star-like shape to a fine polyhedral shape and the grain size of the primary Si was refined from roughly 90-120 μm to 20-50 μm. The eutectic Si phases were modified from a coarse platelet-like/needle-like structure to a fine fibrous structure with discrete particles. The Al-5Ti-C master alloy (0.6 wt%, 30 min) still has a good refinement effect. The ultimate tensile strength (UTS), elongation (El) and Brinell hardness (HB) of Al-20%Si alloy modified by the Al-5Ti-C master alloy (0.6 wt%, 10 min) increased by roughly 65%, 70% and 51%, respectively, due to decreasing the size and changing the morphology on the primary and eutectic Si crystals. The change in mechanical properties corresponds to evolution of the microstructure.

| S-EPMC5453074 | biostudies-other

Effect of Cooling Rate at the Eutectoid Transformation Temperature on the Corrosion Resistance of Zn-4Al Alloy.

Project description:The main purpose of this work was to experimentally determine the effect of the cooling rate during the eutectoid transformation on the corrosion resistance of a hypoeutectic Zn-4Al cast alloy in 5% NaCl solution. This was considered in relation to the alloy microstructure. For this purpose, metallographic and electrochemical studies were performed. It was found that the faster cooling promoted the formation of finer (? + ?) eutectoid structures, which translated into a higher hardness and lower corrosion current density. In the initial stage of corrosion processes the eutectoid structure in the eutectic areas were attacked. At the further stages of corrosion development, the phase ? was dissolved, and the ? phase appears to be protected by the formation of corrosion products.

| S-EPMC7178647 | biostudies-literature

Refining Mechanism of 7075 Al Alloy by In-Situ TiB? Particles.

Project description:The nucleation undercooling of TiB?/7075 Al matrix composites, the microstructure observed after solidification at different cooling rate, and the size and distribution of TiB? particles were investigated. The experimental results have shown that the grain sizes of TiB?/7075 Al matrix composites firstly decreased, then increased, and finally decreased again with the increase of TiB? content. The nucleation undercooling of TiB?/7075 Al matrix composites first increased, then decreased, and finally increased again with the increase of TiB? content when the cooling rates was 5 and 10 °C/min respectively, but kept decreasing with the increase of TiB? content at a cooling rate of 20 °C/min. The melting and solidification process showed no significant change with the decrease of cooling rate in 9.0% TiB?/7075 Al matrix composites. Most small particles can act as heterogeneous nucleus, which induced grain growth and were captured into the grain by the solid/liquid interface. At the same time, most of the larger particles and a minority of the small TiB? particles are pushed into the grain boundary; locating in the grain boundary can hinder the Al atoms from diffusing during the solidification process and restrain ?-Al phase growth. The influence of particles shifted from dominating by locating to dominating by nucleation as the quantity of TiB? particles increased.

| S-EPMC5459188 | biostudies-literature

Electrografting of 4-Nitrobenzenediazonium Salts on Al-7075 Alloy Surfaces-The Role of Intermetallic Particles.

Project description:In this work, the electrografting of Al-7075 aluminium alloy substrates with 4-nitrobenzenediazonium salt (4-NBD) films was studied on a complex aluminium alloy surface. Prior to the electrografting reaction, the substrates were submitted to different surface treatments to modify the native aluminium oxide layer and unveil intermetallic particles (IMPs). The formation of the 4-NBD films could be correlated with the passive film state and the distribution of IMPs. The corresponding electrografting reaction was performed by cyclic voltammetry which allowed the simultaneous analysis of the redox reaction by a number of complementary surface-analytical techniques. Spatially resolved thin film analysis was performed by means of SEM-EDX, AFM, PM-IRRAS, Raman spectroscopy, XPS, and SKPFM. The collected data show that the 4-NBD film is preferentially formed either on the Al oxide layer or the IMP surface depending on the applied potential range. Potentials between -0.1 and -1.0 VAg/AgCl mostly generated nitrophenylene films on the oxide covered aluminium, while grafting between -0.1 and -0.4 VAg/AgCl favours the growth of these films on IMPs.

| S-EPMC8067352 | biostudies-literature

Synthesis of Al₂Ca Dispersoids by Powder Metallurgy Using a Mg-Al Alloy and CaO Particles.

Project description:The elemental mixture of Mg-6 wt %Al-1 wt %Zn-0.3 wt %Mn (AZ61B) alloy powder and CaO particles was consolidated by an equal-channel angular bulk mechanical alloying (ECABMA) process to form a composite precursor. Subsequently, the precursor was subjected to a heat treatment to synthesize fine Al₂Ca particles via a solid-state reaction between the Mg-Al matrix and CaO additives. Scanning electron microscopy-energy-dispersive spectroscopy (SEM-EDS) and electron probe micro-analysis on the precursor indicated that 4.7-at % Al atoms formed a supersaturated solid solution in the α-Mg matrix. Transmission electron microscopy-EDS and X-ray diffraction analyses on the AZ61B composite precursor with 10-vol % CaO particles obtained by heat treatment confirmed that CaO additives were thermally decomposed in the Mg-Al alloy, and the solid-soluted Ca atoms diffused along the α-Mg grain boundaries. Al atoms also diffused to the grain boundaries because of attraction to the Ca atoms resulting from a strong reactivity between Al and Ca. As a result, needle-like (Mg,Al)₂Ca intermetallics were formed as intermediate precipitates in the initial reaction stage during the heat treatment. Finally, the precipitates were transformed into spherical Al₂Ca particles by the substitution of Al atoms for Mg atoms in (Mg,Al)₂Ca after a long heat treatment.

| S-EPMC5551759 | biostudies-other

The Solidification Behavior of AA2618 Aluminum Alloy and the Influence of Cooling Rate.

Project description:In AA2618 aluminum alloy, the iron- and nickel-rich intermetallics formed during solidification are of great effect on the mechanical properties of the alloy at both room temperature and elevated temperatures. However, the solidification behavior of the alloy and the formation mechanism of the intermetallics during solidification of the alloy are not clear. This research fills the gap and contributes to understanding the intermetallic of the alloy. The results showed that cooling rate was of great influence on the formation of the intermetallics. Under the condition of slow cooling, the as-cast microstructures of the alloy were complex with many coarse eutectic compounds including Al₉FeNi, Al₇(CuNi)₅, Si, Al₂Cu and Al₂CuMg. The phase Al₉FeNi was the dominant intermetallic compound, which precipitated at the earlier stage of the solidification by eutectic reaction L → α-Al + Al₉FeNi. Increasing the cooling rate would suppress the formation of the coarse eutectic intermetallics. Under the condition of near-rapid cooling, the as-cast microstructures of the alloy consisted of metastable intermetallics Al₉FeNi and Al₂Cu; the equilibrium eutectic compounds were suppressed. This research concluded that intermetallics could be refined to a great extent by near-rapid cooling.

| S-EPMC5456450 | biostudies-other

Formation of Aluminum Particles with Shell Morphology during Pressureless Spark Plasma Sintering of Fe-Al Mixtures: Current-Related or Kirkendall Effect?

Project description:A need to deeper understand the influence of electric current on the structure and properties of metallic materials consolidated by Spark Plasma Sintering (SPS) stimulates research on inter-particle interactions, bonding and necking processes in low-pressure or pressureless conditions as favoring technique-specific local effects when electric current passes through the underdeveloped inter-particle contacts. Until now, inter-particle interactions during pressureless SPS have been studied mainly for particles of the same material. In this work, we focused on the interactions between particles of dissimilar materials in mixtures of micrometer-sized Fe and Al powders forming porous compacts during pressureless SPS at 500-650 °C. Due to the chemical interaction between Al and Fe, necks of conventional shape did not form between the dissimilar particles. At the early interaction stages, the Al particles acquired shell morphology. It was shown that this morphology change was not related to the influence of electric current but was due to the Kirkendall effect in the Fe-Al system and particle rearrangement in a porous compact. No experimental evidence of melting or melt ejection during pressureless SPS of the Fe-Al mixtures or Fe and Al powders sintered separately was observed. Porous FeAl-based compacts could be obtained from Fe-40at.%Al mixtures by pressureless SPS at 650 °C.

| S-EPMC5503014 | biostudies-other

Granular cooling of ellipsoidal particles in microgravity.

Project description:A three-dimensional granular gas of ellipsoids is established by exposing the system to the microgravity environment of the International Space Station. We use two methods to measure the dynamics of the constituent particles and report the long-time development of the granular temperature until no further particle movement is detectable. The resulting cooling behavior can be well described by Haff's cooling law with time scale τ. Different analysis methods show evidence of particle clustering towards the end of the experiment. By using the kinetic theory for ellipsoids we compare the translational energy dissipation of individual collision events with the overall cooling time scale τ. The difference from this comparison indicates how energy is distributed in different degrees of freedom including both translation and rotation during the cooling.

| S-EPMC9021203 | biostudies-literature

Transcriptomic profiling of HSkMC cells exposed to tungsten alloy particles 2

Project description:Human skeletal muscle cell cultures (HSkMC) were exposed to particles of various tungsten alloys or tantalum and transcriptomic responses after 24 hours were determined by gene expression microarrays in comparison with untreated control cultures.

2015-03-01 | E-MTAB-2993 | biostudies-arrayexpress

Transcriptomic profiling of HSkMC cells exposed to tungsten alloy particles 1

2015-03-01 | E-MTAB-2991 | biostudies-arrayexpress