Heterogeneous nucleation and grain initiation are two different processes in early-stage solidification (ESS), although both are deterministic. Heterogeneous nucleation refers to the formation of a 2-dimensional (2D) nucleus (a crystal plane of the s...
Rare earth elements and transition elements are widely used in aluminum alloys, magnesium alloys and copper alloys due to their unique microalloying effects. With regard to in-depth research on the grain refinement characteristics of rare earth eleme...
Magnesium is a suitable candidate material for temporary implant applications, such as a miniplate, due to its biocompatibility, density, and elastic modulus comparable to that of human bone. The biodegradability property of magnesium can minimize th...
As the lightest structural materials, Mg alloys show great effectiveness at energy saving and emission reduction when applied in the automotive and aerospace fields. In particular, Zr-bearing Mg alloys (non-Al containing) exhibit high strengths and e...
During thermal deformation, grain coarsening due to grain growth and grain refinement resulting from dynamic recrystallization (DRX) collectively influence the deformed grain size. To investigate the separative and comprehensive effects of the two me...
Refinement of as-cast structures is one of the most effective approaches to improve mechanical properties, formability, and surface quality of steel castings and ingots. In the past few decades, addition of rare earths (REs), lanthanum and cerium in...
In this study, TiC0.5N0.5 nanoparticles (NPs) are shown to induce a remarkable grain refinement of aluminum at various cooling rates. The grain refinement mechanisms are systematically investigated by microstructure observation, edge-to-edge matching...
The Ni-based IN792 superalloy is widely applied as a component in industrial turbines and aircraft engines due to its good high-temperature properties and excellent corrosion resistance. Since these components have to suffer from cyclic thermal and m...
Synergistic effect of TiB2 (in form of Al-5Ti-1B) and La on grain refining results in Al-2Cu alloy was investigated. α-Al grains are significantly refined by Al-5Ti-1B. When trace La is added to the melt, further refinement is exhibited. Averag...
The phase structure, grain refinement, and microalloying effect of the Al-5Er-Ti master alloy were analyzed by a refining experiment, microhardness test, OM, SEM, and XRD. The results show that when the Er/Ti atomic ratio is 2.7, the refining effect...
This paper studies the grain refinement mechanisms of 5A06 aluminum alloy sheets in cold rotary forging (CRF). The results show that the grains are clearly refined from 25.1 µm to 11.8 µm during the CRF process. The grain refinement mecha...
The work looked into the grain refinement process of Mg alloy during asymmetrical rolling with a focus on the role of twin. The present sample was deformed at ambient temperature by single operation with the height reduction of 50% at the roll speed...
It has long been recognized that grain refinement of Mg-Al alloys is difficult, although various methods have been tried. In the present paper, a novel grain refiner, Al-3.4V-1B master alloy, has been developed to refine the as-cast AZ91 alloy. A com...
Phase-field modeling of rapid alloy solidification, in which the rejection of latent heat from the growing solid cannot be ignored, has lagged significantly behind the modeling of conventional casting practices which can be approximated as isothermal...
The inefficiency of grain refinement processes has traditionally been attributed to the limited utilization of heterogeneous nucleation particles within master alloy systems, resulting in the formation of abundant inactive particles. This study aims...
Bobbin friction stir welding (BFSW), with its fully penetrated pin and double-sided shoulder, can provide high rates of heat generation. This produces solid-state thermo-mechanical grain refinement. In this paper, the microstructure evolution of the...
Grain refinement using oxide additions is commercially feasible and ecofriendly. MgAl2O4 has a lattice structure similar to Al and small lattice misfits with Al, and it can be an effective nucleation core when it meets certain conditions. In this pap...
This paper investigates the microstructural evolution and grain refinement kinetics of a solution-treated Cu–0.1Cr–0.06Zr alloy during equal channel angular pressing (ECAP) at a temperature of 673 K via route BC. The microstructural change during pla...
The effect of B addition on the microstructure and mechanical properties of AM50 was investigated, and the mechanism of grain refinement was clarified. Optical microscopy, X-ray diffraction, scanning electron microscopy, and electron probe microanaly...
Grain refinement is of importance for metallic materials since it provides multiple benefits, such as improved castability, reduced casting defects and improved mechanical properties. From extensive research carried out in the past decades, it has be...
It is well known that it takes some time for the solid phase to completely dissolve upon melting, especially inside the defects of insoluble particles, e.g. oxides. Until then the oxides remain active solidification substrates in the case of subseque...
Refined microstructures achieved by cyclic heat treatment significantly contribute to improving the wear resistance of steels. To acquire the refined microstructures of 65Mn low-alloy steel, first, the specimens were solid solution-treated; then, the...
The present analysis addresses the solidification and thermodynamic parameters involved during the solidification of aluminum (Al)-based alloys as presented in the literature using different systems viz., binary aluminum-boron (Al-B) and aluminum-tit...
In this work, a systematic review of the published literature was conducted, following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, on the ultrasonic treatment of magnesium-aluminium alloys for grain refin...
Aluminum and its alloy magnetron sputtering targets, owing to their superior electrical/thermal conductivity and robust substrate adhesion, serve as critical materials in advanced electronics and information technologies. It is known that the microst...
Equal channel angular pressing (ECAP) and multi-axial compression deformation (MAC) are severe plastic deformation (SPD) processes that produce bulk nanostructured materials with ultrafine grains. The grains could be observably refined by multi-pass...
The microstructures of the as-cast and as-extruded Mg–14 wt. % Li–1 wt. % Al (LA141) and Mg–14 wt. % Li–2 wt. % Sn (LT142) were observed by optical and scanning electron microscope (SEM), X-ray diffraction (XRD) and differential scanning calorimetry...
A novel grain refinement method using a CaMgSn intermetallic phase was investigated via adding a Mg–CaMgSn master alloy to an AZ31 magnesium alloy. The results showed a remarkable grain refinement effect in as-cast AZ31, with the average grain size r...
In order to obtain the desired mechanical properties of products, an innovative method of loading parameter designs for acquiring the desired grain refinement is proposed, and it has been applied in the compression process of Ni80A superalloy. The de...
In this article, the evolution of microstructural characteristics of selectively laser-melted AlSi10Mg alloy subjected to equal channel angular pressing (ECAP) is investigated. The microstructures were analyzed in detail using scanning electron micro...
Three types of Al–5Ti master alloys were synthesized by a method of thermal explosion reaction in pure molten aluminum. Performance comparison of Al–5Ti master alloy in grain refinement of commercial purity Al with different additions (0.6%, 1.0%, 1....
Ti-6Al-4V components built with wire plus arc additive manufacturing (WAAM) generally have long columnar β grains that cause anisotropic behavior when the material undergoes static and cyclic failure. Recently, machine hammer peening (MHP) has b...
The excellent properties of ultra-fine grained (UFG) materials are relevant to substantial grain refinement and the corresponding induced small grains delineated by high-angle grain boundaries. The present study aims to understand the grain refinemen...
It is high of commercial importance to generate the grain refinement in alloys during solidification by means of electromagnetic fields. Two typical patterns of electromagnetic fields, pulsed electric currents (ECP) and traveling magnetic field (TMF)...
The present study proposes a novel method, i.e., combined severe shot peening (SP) and reversion annealing treatment, to grain-refine the surface layers of 304L austenitic stainless steel. Steel specimens were shot-peened at 0.7 MPa for 30 min, intro...
This study aims to investigate the combined effect of niobium (Nb) microalloying and austenite grain refinement, using a specific heat treatment cycle, on the microstructure and tribological properties of Armox 500T steel. In this work, Nb addition a...
Based on electron backscattered diffraction analysis and transmission electron microscopy observation, the mechanism of inhomogeneous grain refinement in a NiTiFe shape memory alloy (SMA) subjected to single-pass equal-channel angular extrusion (ECAE...
The effect of trace Sc and Zr on grain refinement of Al-5.0Mg-3.0Zn as-cast alloy was investigated by optical microscopy and scanning electron microscopy with EDS. The results indicated that the critical quantities of Sc and Zr for Al-Mg-Zn alloy to...
The present research uses in-situ neutron diffraction to examine the effect of grain refinement on grain growth during solidification of Al-5 wt.% Cu and Mg-5 wt.% Zn alloys. The alloys were grain refined through additions of Al-5Ti-1B and Zr, respec...
To investigate the relationship between the dislocation configuration and the grain refinement in the NV E690 cladding layer caused by laser shock peening, NV E690 high-strength steel powder was used to repair prefabricated pits in samples of 690 hig...
The grain structure of metals changes significantly during severe plastic deformation (SPD), and grain refinement is the main process associated with SPD at low homologous temperatures. Products made of ultrafine-grained materials exhibit improved pe...
High-entropy alloys (HEA) as a kind of new binder for cemented carbide have garnered significant attention. In this work, WC/(17~25 wt.%)Al0.5CoCrFeNiTi0.5 cemented carbides were prepared by hot pressing sintering (HPS), and the reactions between WC...
The superheating process is a unique grain refining method found only in aluminum-containing magnesium alloys. It is a relatively simple method of controlling the temperature of the melt without adding a nucleating agent or refining agent for grain r...
The present study was undertaken to investigate the effect of continuous and discontinuous (cyclic) solution heat treatment on the athermal and isothermal ε martensite phase transformation in Co-28Cr-6Mo-0.3C implant alloy. The results showed...
The nucleation and grain growth that occur during solidification have been extensively examined, but insight into the influence of an external field on the formation of heterogeneous crystal nuclei above the liquidus remains unclear in the peritectic...
In this study, an insert mold casting was fabricated by inserting 2024 Al extruded rods into a 2024 Al melt. The molds were kept at a 2024 Al melt for different times. The 2024 Al extruded rods were used to refine the 2024 Al alloy grains because the...
Additively manufactured (AM) stainless steel has attracted a lot of attention for its competitive performance advantages over parts prepared by traditional methods. However, the influence of the powder characteristic of AISI 304L stainless steel on t...
A series of Al-4Ti master alloys with various TiAl3 particles were prepared via pouring the pure aluminum added with K2TiF6 or sponge titanium into three different molds made of graphite, copper, and sand. The microstructure and morphology of TiAl3 p...
Room-temperature rotary swaging was conducted on microalloyed high-ductility Mg-0.7Sm-0.3Zr alloy rods to investigate microstructural and mechanical variations across different swaging passes and radial positions. The results indicate that following...
What is nucleation core origin during alloy solidification, especially for equiaxed grains? Different dependence degrees of the magnitude or occurrence of element content variation could shed light on this long-standing issue in actual large ingots....
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