Sulfide solid electrolytes (SSEs) have captured plentiful interest on account of their high ionic conductivity and appropriate mechanical strength. However, the poor air stability and cost‐intensive ...preparation process of SSEs limit their applications. Herein, a novel ultimate‐energy mechanical alloying (UEMA) approach is applied to rapidly synthesize the argyrodite‐type electrolytes in a one‐pot process. According to the hard‐soft‐acid‐base theory and the first‐principles density functional theory (DFT) calculation, In‐doping in Li6PS5I is attempted to enhance air stability and the experimental results demonstrate the success of this approach. The synthesized Li6.5In0.25P0.75S5I electrolyte has a high ionic conductivity (1.06 mS cm–1), and also presents excellent interfacial stability against Li metal, benefiting from the formation of a LiI‐rich interphase layer. The assembled Li–S battery with Li6.5In0.25P0.75S5I as an interlayer delivers a high discharge capacity (954 mAh g–1) and presents the capacity retention of 96% after 200 cycles. The In‐doped Li6PS5I is a novel promising electrolyte with high air stability and ionic conductivity for the application of all‐solid‐state lithium metal batteries.
Herein, the ultimate‐energy mechanical alloying method is adopted to rapidly synthesize argyrodite‐type electrolytes in a one‐pot process. In‐doping is further utilized to optimize the Li6PS5I electrolyte. The Li6.5In0.25P0.75S5I electrolyte with high ionic conductivity, good air stability, and excellent interfacial stability is obtained and leads to a high discharge capacity (954 mAh g–1) and a capacity retention of 96% after 200 cycles.
Uranium-molybdenum (U-Mo) alloys show promise as a nuclear fuel system due to their high thermal conductivity and fuel loading capability. However, U-Mo systems are susceptible to irradiation induced ...swelling ultimately affecting the cladding via mechanical and chemical interactions. To address these shortcomings, this research investigated the formation of uranium mononitride (UN) nanoparticles within a 90 wt% U/ 10 wt% Mo (U-10Mo) matrix to act as a prospective defect sink for fission products at nanometric hetero-interfaces. To promote the formation of UN, U-10Mo powders were mechanically alloyed under a high purity nitrogen atmosphere. Variations of the milling process investigated included media size, duration of milling, and number of times the milling jar was re-aerated with nitrogen gas. Characterization of the fuel microstructure was completed using light element analysis, X-ray diffraction, scanning and transmission-electron microscopy, electron energy loss spectroscopy, and atom probe tomography. UN nanoparticles measuring 1–5 nm in radius were observed in the U-Mo matrix as early as 1 h into the mechanical alloying process. Milling time in excess of 10 h was found to lead to deleterious effects induced by the stainless-steel milling media.
With excellent safety and outstanding energy density, all-solid-state batteries is of a prospect for surpassing liquid Li+ batteries. Li6PS5Cl, exhibits desirable ductility and good Li+ conduction ...property, which is the most commonly used solid-state electrolyte. Herein, Li3.75Si alloys have been prepared by high energy milling technology as an anode to couple with NCM811 cathode and demonstrated an outstanding capacity. During the charging/discharging process, a microstructural defect surface was obtained, and a large impedance interface was verified by EIS tests.
An equiatomic CoCrFeNiMn high-entropy alloy was synthesized by mechanical alloying (MA) and spark plasma sintering (SPS). During MA, a solid solution with refined microstructure of 10 nm which ...consists of a FCC phase and a BCC phase was formed. After SPS consolidation, only one FCC phase can be detected in the HEA bulks. The as-sintered bulks exhibit high compressive strength of 1987 MPa. An interesting magnetic transition associated with the structure coarsening and phase transformation was observed during SPS process.
Display omitted
Thermal stability is a crucial issue for engineering application of tungsten, especially as plasma facing material in future fusion reactor. Two kinds of ODS-W alloys of W-0.5Y2O3 (WY) and ...W-0.5Y2O3-0.25Ti (WYT) were fabricated by ball milling and spark plasma sintering aiming at formation of oxide dispersoids with different crystallographic structures. Thermal stability of both ODS-W alloys was evaluated in terms of microhardness and microstructure evolution during isothermal aging at 1100 °C. Dispersoids of sesquioxide Y2O3 were identified in sintered WY, while pyrochlore Y2Ti2O7 with finer size and higher number density were developed in sintered WYT, resulting in higher bending strength of 1020 MPa and microhardness of 880 HV. Compared with sesquioxide Y2O3, complex dispersoids of pyrochlore Y2Ti2O7 exhibited much better coarsening resistance during isothermal aging at 1100 °C up to 100 h, where the intracrystalline and GB dispersoids maintained around 10 nm and 30 nm, respectively. The excellent coarsening resistance of complex Y2Ti2O7 with pyrochlore structure contributed to grain refinement and improved microstructure stability of WYT due to the effect of Zener drag.
•Formation of complex Y2Ti2O7 with pyrochlore structure was achieved in ODS-W alloy.•Complex dispersoids of Y2Ti2O7 showed finer size and higher number density.•Intracrystalline dispersoids of Y2Ti2O7 had coherent relationship with W matrix.•Pyrochlore Y2Ti2O7 exhibited better coarsening resistance during aging at 1100 °C.•Thermal stability of ODS-W alloy was improved through formation of complex Y2Ti2O7.
The present work is focused on understanding the role of Ruthenium (Ru) and Yttrium (Y) on the superconducting properties of the A15 Nb3Sn intermetallic compound. Ru and Y shows different solubility ...limit within the Nb3Sn matrix. Ru and Y-doped Nb3Sn superconducting alloys were prepared through mechanical alloying (MA) route followed by sintering using Field Assisted Sintering Technique (FAST). Analysis by X-ray diffraction demonstrates a significant decrement in crystallite size up to 0.5 wt% for the Ru-doped Nb3Sn followed by a significant increment when doping level reaches 1 wt% Ru. This could be the combined effect of structural disorderliness and Ru dissolution within the Nb3Sn matrix. While a significant increase in the crystallite size is observed for 0.5 wt% Y-doped Nb3Sn and no further change up to 1 wt% Y. This change could be a result of limited solubility of Y within the Nb3Sn matrix. Meanwhile, excessive Y plays an important role in the formation of additional flux pinning centers. The critical current density (Jc) shows a significant increase for all the Y-doped Nb3Sn alloys by a factor of 29 % due to the formation of Y2O3 from the residual Y, which is assumed to serve as additional flux pinning center. The Y2O3 particles was also considered as a possible cause of pinning down of grain boundaries in addition to NbO leading to grain refinement through Zener pinning. Ru-doped Nb3Sn alloys also exhibit an increase in Jc compared to pristine Nb3Sn, but only in concentrations up to 0.5 wt% Ru. At higher applied field, even 1 wt% Ru shows slight increase in Jc than pristine Nb3Sn. Y-doped samples showed superior functional properties.
•The concentration of dopants in Nb3Sn plays a crucial role in defining its functional properties.•The solubility limit of dopants has significant effects on superconducting properties of Nb3Sn.•Yttrium (Y) with limited solubility enhances superconductivity while Ruthenium (Ru) does the opposite.•Formation of additional flux pinning centers led to higher functional behaviour for Y modified Nb3Sn.
•Several methods of preparation of magnetic abrasives have been discussed.•A thorough evaluation, comparison of magnetic characteristics and the performance of three types of magnetic abrasives is ...studied.•The finishing efficiency of these magnetic abrasives has been assessed and compared through detailed experimentation.
The Magnetic Abrasive Finishing (MAF) technique is proficient in refining hard-to-reach surfaces such as the inner surfaces of bent tubes and capillary tubes. Magnetic abrasives (MAs) function as multi-point cutting tools, significantly contributing to attaining the desired surface quality on the workpiece. Numerous methods, detailed in the literature, exist for the preparation of magnetic abrasives. Previous research emphasizes on optimizing the parameters of the MAF process for specific magnetic abrasive formulations. A thorough evaluation and comparison of their performance is needed. In this study, MAs are prepared with three different techniques viz. Simply mixed, Sintered, and Mechanical Alloying techniques. The magnetic characteristics of these MAs were evaluated by measuring the actual magnetic flux density (MFD, B) within the magnetic abrasive brush. Additionally, their finishing performance was assessed through experiments conducted on the MAF setup to refine the inner surface of a brass tube. The results indicated that MAs produced through mechanical alloying exhibited superior magnetic properties and finishing efficiency. The minimum average surface roughness attained by mechanically alloyed, sintered, and simply mixed magnetic abrasives is 0.51 µm, 0.71 µm, and 1.15 µm, respectively, after finishing for 60 min under identical experimental conditions. A direct correlation is observed between magnetic flux density (B) and the finishing efficiency of magnetic abrasives, with mechanically alloyed magnetic abrasives demonstrating better finishing efficiency and superior magnetic properties.
This study investigated the fabrication and characterization of two new zinc-titanium-based alloys. The Zn-xTi alloys (x = 4 and 10 wt%) were mechanically alloyed by powder metallurgy for 10 h. The ...spark plasma sintering (SPS) method shaped the resulting powder. The fabricated samples were evaluated in terms of morphology and structure by XRD, SEM, and microhardness tests. The obtained parts’ corrosion resistance and biological behavior were also examined by potentiodynamic polarization analysis, electrochemical impedance spectroscopy (EIS), and MTT tests. The results showed that alloying increased the hardness compared to pure zinc samples. The corrosion test results indicated higher corrosion resistance of Zn–4Ti alloy than Zn–10Ti alloy. The cell toxicity test, performed indirectly by the extraction process, clearly showed lower toxicity of Zn–4Ti alloy compared to the other alloy. In the extractions with low concentrations (25 % and 12.5 %), no cell toxicity was observed in the Zn–4Ti alloy. This research concludes that the alloy containing 4 wt% titanium can be a suitable candidate for making biodegradable implants.
•This study explored the fabrication and characterization of two novel zinc-titanium-based alloys (4 and 10 wt% Ti) that underwent mechanical alloying and were shaped using the spark plasma sintering (SPS) method.•Corrosion tests demonstrated superior corrosion resistance in the Zn–4Ti alloy compared to the Zn–10Ti alloy.•Cell toxicity tests, conducted indirectly through extraction processes, indicated lower toxicity in the Zn–4Ti alloy.•The alloy containing 4 wt% titanium shows promise as a viable candidate for producing biodegradable implants.
In the present work the synthesis of multicomponent nanocrystalline Al0.1- 0.5(Mn)CoCrFeNi HEA powder feedstocks by mechanical alloying (MA) through high energy ball milling to produce HEA coatings ...with cold spraying were studied. Pure (>99.5) elemental powders of Al (Mn), Co, Cr, Cu, Fe & Ni were mixed in predetermined ratios and mechanically alloyed under Ar gas in a Planetary Ball Mill. MA HEA powder feedstocks were characterized by optical microscopy, SEM+EDAX, XRD & XPS to determine powder particle size, shape & distribution, particle surface condition, chemical composition, crystal & phase structures & microstructures. MA-processed Al-HEA powder feedstocks exhibited tri-modal particle size distribution (PSD) while Mn-HEA had four distinct PSD modes. Fine size fraction of the MA- HEA powders contained A2/B2 (BCC) harder phases with lattice parameters of 2.8831 and .2.8690 Å, respectively and coarse size fraction contained (ductile) softer A1 phase/Cu-rich regions combined (FCC) having a lattice parameter of 3.6181 Å. The ratio of the phases varied depending on the Al and Mn contents in the powder. For higher aluminium contents, there was more disordered A2/B2 phases and less disordered A1 phase in Al0.1–0.5 HEA powder feedstocks. A1 phase contained Fe, Cr, Co and Ni; A2 phase contained Fe, Cr; and B2 phase contained Al, Ni elements in Al0.1–0.5 HEA powder feedstocks. There were passive surface oxide films on the rough surfaces of MA HEA powder feedstocks consisting of a main mixture of surface oxides such as Al2O3, MnO, Cr2O3, Mn2O3, and minor oxides such as CuO, Fe2O3, NiO, Fe3O4, and a few CoCr2O4 spinel oxide. Dual FCC-dual BCC phase prediction of thermodynamic stable phase formation criteria reported in the literature on MA-HEA powder feedstocks were consistent with the experimental results of the present study.
Display omitted
•Phase formation predictions.•Phase differentiation via LM, SEM, XRD deconvolution & PSD analyses.•HEA coating characterizations.
In this study, the CoCrNiFeTax high entropy alloys were prepared using mechanical alloying (MA). Effects of different Ta contents and mechanical alloying on the phase formation, microstructure ...development, and mechanical properties of CoCrNiFeTax model alloys were investigated. The results suggest that the alloy exhibits a dual-phase structure composed of both FCC and Laves phases. Ta-rich oxides can be further generated after high-temperature sintering. The CoCrNiFeTa0.5 sample demonstrates a good combination of strength and ductility due to the uniform and refined microstructure of the dual phases. However, the alloys with a high Ta content generated a large number of the formation of Lavas phases, Ta-rich phases, and Ta-oxides, which can cause embrittlement of materials, resulting in a significant deterioration of mechanical properties.
•FCC/BCC solid solution phases are obtained after 16h of milling.•Materials are composed of FCC and Laves phases after sintering.•Laves phase, Ta-rich phase/oxide increase with Ta content.•CoCrFeNiTa0.5 has a good combination of strength and ductility.•High Ta content causes embrittlement of model alloys.
