Mechanical Properties of Ultrafine-Structured Al-Si-Mg …
The microstructure consists of homogenous dendritic structure with ultrafine size and spherical eutectic Si crystals with the diameter of about 50 nm. These factors increase microhardness (119 ± 8 HV) much higher than those made by conventional direct casting (DC) methods. As-spun ribbons also show high ultimate tensile strength (UTS) …
Ultrafine grained structure formation in steels using …
Here, the formation of ultrafine ferrite (UFF) involves the dynamic transformation of a significant volume fraction of the austenite to ferrite. This dynamic strain induced transformation (DSIT) arises from the introduction of extensive intragranular nucleation sites that are not present in conventional controlled rolling.
Unraveling the Atomic Structure of Ultrafine Iron Clusters
Unraveling the atomic structures of ultrafine iron clusters is critical to understanding their size-dependent catalytic effects and electronic properties. Here, we describe the stable close-packed ...
Advanced mechanical properties of pure titanium with ultrafine …
Thin wires and foils comprising of ultrafine-grained pure titanium (Ti) were made by combined processes of multi-directional forging (MDFing) and either drawing or rolling processes. The MDFed wires and foils exhibited higher tensile strength than the conventional pure Ti wires and plates due to the ultrafine-grained structure.
Polylactide/cellulose pulp composite paper with laminate structure …
2.4. Characterization2.4.1. Mechanical property. The universal tensile machine (Instron-68TM-10, USA) was used to measure tensile strength and tensile modulus of the composite paper (50 mm × 5 mm) at room temperature and with a strain rate of 5 mm/min, The tensile strength of the PLA/CFs composite paper (120 mm × 15 mm) were …
Effect of rolling reduction on ultrafine grained structure and
In this study, the effect of the rolling reduction ranging from 25 to 70% (equivalent strains of 0.3–1.5) on the ultrafine grained structure and the mechanical properties of the plain low-carbon steel (Fe–0.13 wt% C) processed from martensite starting structure was studied. In the as-deformed specimen, the area fraction of the region ...
[PDF] Structure-properties relationship of ultra-fine grained …
Abstract The effect of vanadium microalloying on ultra-high strength dual phase (DP) ferrite-martensite steel microstructure and properties was studied. It was …
Recent progress in ultrafine 3D Pd-based nanocubes with …
Recent progress in ultrafine 3D Pd-based nanocubes with multiple structures for advanced fuel cells electrocatalysis. Author links open overlay panel Kewang Zhang a, Cheng Wang a, Fei Gao a, ... Generally, the special hollow nanocubes structure with outstanding structural advantages can play a great role in the field of electrocatalysis.
Formation mechanism of ultrafine α+β structure in Ti-6Al …
Although massive transformation has been increasingly observed in titanium alloys, the decomposition mechanism of the massive transformation product (α m) is still unclear.Here, the β→α m →α+β continuous phase transformation in Ti-6Al-4V alloy during cooling was studied. We found that massive transformation occurs at a moderate …
Structure and properties of ultrafine-grained CoCrFeMnNi …
abstract = "CoCrFeMnNi high-entropy alloy (HEA) materials were fabricated using mechanical alloying (MA) and spark plasma sintering (SPS). The MA time, SPS temperature, and contaminations strongly affected the …
Ultrafine-Grained Materials
Ultrafine-grained (UFG) materials are a new class of metals and alloys characterized by a microstructure with grain sizes less than 1 μm and nanostructural …
Facile route to bulk ultrafine-grain steels for high strength …
To achieve an ultrafine structure, the 0Cu was cold-rolled from 8 mm to 4 mm and annealed at 800 °C for 5 min to refine the coarse grains after homogenization. Then the 4-mm-thick plate was cold ...
Effects of alkaline activators on pore structure and …
At ambient temperature, the rate of geological polymerization is extremely slow. The use of ultrafine metakaolin with smaller particle sizes will increase the reactivity of geopolymer and improve the strength of geopolymer, which is conducive to its application in practical engineering [24].Therefore, this experiment uses ultrafine metakaolin (UMK) …
Ultrafine grained structure formation in steels using dynamic …
The present paper reviews the status of the production of ultrafine grained steels through relatively simple thermomechanical processing. This requires deformation …
W–Cu composites with submicron- and nanostructures: progress …
A W-25 wt.% Cu composite with an ultrafine structure was shown to have higher stability, hardness (~230 HB), and compressive strength during thermal cycling (Fig. 4) and improved wear resistance ...
The Recrystallization Behavior in Ultrafine-Grained Structure …
A simple process of 50% cold-rolled and annealed at different temperatures and times to obtain ultrafine-grained structured low-carbon steel with superior mechanical properties is utilized in this investigation. The microstructure evolves from bulky austenite to lathy martensite and then ultrafine ferrite grain with nanocarbide particles. Recovery …
Effect of chemical structure and molecular weight on the …
2.3. Preparation of HKLs-based ultrafine carbon fibers. HKLs ultrafine fibers were prepared using electrospinning method [9]. 2 g HKLs were first dissolved in 4 mL of DMF under magnetic stirring at 95 °C with a speed of 1200 rpm.Then, 0.02 g PEO was added into the solution and further continuously stirred for 12 h to improve the …
Effects of Emulsion Droplet Size on the Structure of …
Electrospinning of cellulose nanocrystals (CNC)/poly(lactic acid) (PLA) emulsions has been demonstrated to be an effective dispersion and alignment method to control assembly of CNC into continuous composite ultrafine fibers. CNC–PLA nanocomposite random-fiber mats and aligned-fiber yarns were prepared by emulsion …
Ultrafine Grained Duplex Structure Developed by ART …
The ultrafine grained duplex structure in 0.1C-5Mn was resulted from the the sluggish Mn-diffusion and the extra high Gibbs free energy of ferrite phase. Based on the analysis of the microstructure evolution, it was pointed out that the intercritical annealing of the medium-Mn steels could be applied to fabricate an ultrafine duplex grained ...
Ultrafine core-shell BaTiO3@SiO2 structures for …
Ultrafine (≤ 10 nm) core-shell BaTiO 3 @SiO 2 (BT@SO) nanostructures are synthesized and proved to be superior fillers for high-energy density ceramic-polymer nanocomposite films.. Flexible and transparent BT@SO/PVDF nanocomposite films with outstanding energy storage performance (maximal U dis = 11.5 J/cm 3 at E b = 420 …
Superior strength and ductility of 316L stainless steel …
In summary, the ultrafine grains in micro-nano composite structures of 316L stainless steel are mainly obtained through three ways of as-cast structure nanocrystals reservation, deformation-induced martensite transformation and deformed austenite grain recovery and recrystallization. 3.3.2.
Intercritical Rolling Induced Ultrafine Lamellar Structure …
The medium-Mn steel with ferrite and austenite structure was rolled in the intercritical region down to different rolling reduction. The microstructure and mechanical properties of the rolled steels were investigated by scanning electron microscopy, transmission electron microscopy, X-ray diffraction and tensile tests. It was found that …
HRTEM analysis of the aggregate structure and ultrafine …
Understanding the change in coal structure during heat treatment is the basis of efficient and clean utilization of coal. In this study, high-resolution transmission electron microscopy (HRTEM ...
Synthesis and Structure of Ultrafine Zeolite KL (LTL) Crystallites …
Synthesis conditions were identified leading to agglomerates of nearly cylindrical zeolite nanocrystals with dimensions less than 50 nm in the channel direction and approximately 10 nm in diameter (in the direction perpendicular to the zeolite channels). The nanocrystals form agglomerates with approximate particle sizes ranging from 20 to …
Heterogeneous lamella structure unites ultrafine-grain …
DOI: 10.1073/pnas.1517193112 Corpus ID: 22643506; Heterogeneous lamella structure unites ultrafine-grain strength with coarse-grain ductility @article{Wu2015HeterogeneousLS, title={Heterogeneous lamella structure unites ultrafine-grain strength with coarse-grain ductility}, author={Xiaolei Wu and Muxin Yang …
Ultra-fine grained structure formation through deformation …
This can be attributed to the formation of UFAGs and SMFGs inside the shear bands. It is found that the submicron/ultra-fine grained structure of the steel after …
In-situ interfacial layer with ultrafine structure enabling zinc …
The interfacial layer with ultrafine particles is formed by a simple reduction reaction of sodium stannate to metal Sn. This is a straightforward and efficient strategy …
Research on the forming quality and mechanical properties …
The further power spinning (FS) on the cylindrical parts with ultrafine-grained (UFG) structure was carried out to further improve the mechanical properties of the cylindrical parts. The forming quality and microstructural evolution of the spun parts made of ASTM1020 steel during FS were investigated. The results show that the forming quality …
Grain size, chemistry, and structure of fine and ultrafine …
DOI: 10.1016/J.JAEROSCI.2009.08.004 Corpus ID: 94598903; Grain size, chemistry, and structure of fine and ultrafine particles in stainless steel welding fumes @article{Moroni2009GrainSC, title={Grain size, chemistry, and structure of fine and ultrafine particles in stainless steel welding fumes}, author={Beatrice Moroni and Cecilia …
Effect of rolling reduction on ultrafine grained structure and
That is, the ultrafine structure in the specimens annealed at the warm temperature around 500 °C is evolved mainly from the LDC structure in the cold-rolled specimens. When annealing temperature increases, the coarse grains with grain size of a few micrometers were observed in addition to the ultrafine grained microstructure.