316不锈钢因其优异的耐蚀和加工性能而得到广泛应用,但其宽泛的成分范围会导致性能波动。本文首先将置换型固溶合金化元素归类为稳定铁素体的类Cr元素（Cr,Si,Mo）和稳定奥氏体的类Ni元素（Ni,Mn）。进而引入“团簇加连接原子”模型,给出该不锈钢的16原子成分单元,由此将现有国标成分区间解析成五个16原子成分式,分别对应于两类元素的上下限（Cr,Si,Mo） 3.0625,3.5 -（Ni,Mn） 1.75,2.25 -Fe bal 和中值（Cr,Si,Mo） 3.25 -（Ni,Mn） 2 -Fe bal 。采用氩气保护电弧炉熔炼,用真空箱式炉实施均匀化处理（1150℃/2h,炉冷）,冷轧至5 mm薄片（变形量约50%）,再实施固溶处理（1050℃/0.5h,水淬）。类Ni元素含量最低的Ni 1.75 合金组织中出现铁素体相,对应的质量百分比成分区间为（21.2～18.5）(Cr,Si,Mo)-11.4（Ni,Mn）-Fe;其它三个样品均为单一奥氏体相。经固溶后,平均维氏硬度约为160,最高为174,均满足国标要求（低于200）。在质量分数为3.5%NaCl溶液中的电化学腐蚀实验结果表明,类Cr元素含量最高的Cr 3.5 -Ni 2.25 -Fe bal 合金（Fe-17.8Cr-0.6Si-2.7Mo-14.0Ni-0.8Mn-0.021C）体现出最强的耐蚀性能,成分式中类Ni元素原子个数在2以上的合金也表现出较强的耐蚀性,对应的质量百分比成分区间为（18.4～21.1）(Cr,Si,Mo)-（14.7～13.0）(Ni,Mn)-Fe。类Cr元素含量高的合金点蚀电位（0.211 V）也高。综上,Cr 3.25 -Ni 2 -Fe bal （Fe-16.7Cr-0.4Si-2.7Mo-11.9Ni-1.2Mn-0.021C）既能形成单相奥氏体,又具有满足标准要求的维氏硬度（～160HV）,并且其耐蚀性也在高的水平(自腐蚀电位-0.082 V、腐蚀电流密度1.83×10 -6 A·cm -2 、耐点蚀当量25.6、点蚀电位0.19 V),合金化元素含量适中,是最佳合金。

The superior high-temperature performance of Inconel 718 is originated mainly from the precipitation strengthening via Nb, Al, and Ti alloying. Inappropriate contents of the precipitation elements may lead to over-strengthened solution state and insufficiently strengthened aging state. We have previously identified the alloy composition formula [(Nb,Al,Ti)(1)-(Ni,Fe,Cr,Mo)(12)](Ni,Fe,Cr,Mo)(5) using the cluster formula approach, where the 18-atom structural unit is composed of a nearest-neighbor cluster, centered by one precipitation elements, plus five glue atoms situated at the next neighbors. On the basis of this formula, the present work designs a series of alloys using (Nb,Al,Ti) = 0.93, 1, and 1.06, with 4.9 and 5.5 wt % Nb, 0.68 and 0.5 wt % Al, and 1.10 wt% Ti corresponding to the upper-to-middle ranges in the ASTM standard. In particular, when the total number of atoms in the formula is equal to one, (Nb0.6Al0.2Ti0.2), the alloy is soft at the solution state (sigma(UTS) = 825 MPa < 965 MPa of the standard and EL = 70.3 % > 30 %) and reaches high strength levels after aging (sigma(UTS) = 1400 MPa > 1240 MPa and EL = 23.4 % > 12 % at room temperature, sigma(UTS) = 1100 MPa > 965 MPa and EL = 10.2 % > 5 % at 923 K). This alloy also shows the lowest coarsening rate of 4-7 x 10(-3) nm(3) s(-1) after long-term aging at 923 K, lower than the prevailing coarsening rate of about 16 x 10(-3) nm(3) s(-1).

Co-Cr-based alloys are known for their superior high-temperature wear and corrosion resistance but they all show complex chemistries (such as Co-31Cr-12.5W-0.5Mo-1.5Fe-1.5Ni-1Si-0.5Mn for popular Stellite 1). The present work addresses the composition origin of these alloys using our cluster formula approach. Theoretically, the chemical unit of hexagonal close-packed structure with atoms of similar atomic radii is composed of a nearest-neighbor twinned-cuboctahedral cluster of thirteen atoms plus three next-neighbor glue atoms. To validate this 16-atom unit for Co-Cr, the Co56Cr44 eutectic is first interpreted via combining the chemical formulas of Co3Cr (Ni3Sn ordered structure based on hexagonal close-packed structure) and sigma-CoCr (ordered from BCC solid solution): [Co-Cr4Co8]Co-2-xCr(1)+x + [Co-Cr8Co6]Co-1+xCr(2)-x = [Co-Cr4Co8 +Co-Cr8Co6]Co3Cr3 = Co19Cr15 approximate to Co55.9Cr44.1. It is found that Co-Cr-based industrial alloys satisfy the formula [Co-Cr4Co(8)]Co(2-x)Cr1+x, with x = 0 similar to 2.5, where Co and Cr represent atoms similar to Co and Cr, respectively, as exemplified by Stellite 1 formulated by [Co-Cr4Co8]Cr-3, and Haynes 25 and MP35N by [Co-Cr4Co8]Co2Cr1. Using a known eutectic point to validate the existence of cluster formulas constitutes a straightforward way to understanding the compositions of industrial alloys.

Superalloys feature multi-elements and complex elemental ranges, which makes the proper composition selection difficult. In fact, more strict composition standards generally apply in practical productions. The objective of this paper is to understand and eventually to renew the composition standard via example of the most common grade Inconel 718. We have recently shown that t he alloy chemistry originates from a nearest-neighbor cluster [center-shell] plus a few next-neighbor glue atoms, or expressed in cluster for-mula [center-shell] (glue atoms). By grouping the elements into Ni = (Ni, Co, Cu, Fe), Cr = (Cr, Mn, Si, Mo), and Nb = (Nb, Al, Ti), it is found that the reported alloys fall within a narrow composition zone Ni11.0-13.0-Cr3.5-4.5-Nb1 confined by cluster formulas of 16 and 18 atoms. This composition zone is also expressed in terms of 288-atom supercluster formulas, Ni198-208-Cr63-72-Nb16-18, which leads to coordi-nated elemental variations in wt.%: 69.0 <= Ni + Co + Cu + Fe <= 72.7; 19.8 <= Cr + Mn + 1.7 Si + 0.6 Mo <= 22.8; 8.7 <= Nb + 3.2 Al + 1.9 Ti <= 9.8. Within this composition zone, Ni206-Cr65.5-Nb16.5 is further pinpointed and validated by our own experiments to possess the optimal match of strength and plasticity both at room and at 923 K.(c) 2022 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

铜和铜合金凭借其高导电性、导热性、易加工性和耐腐蚀等特性被广泛应用于电接触材料、电子封装材料、热交换材料等领域,然而铜合金强化过程中强度和电导率、热导率之间此消彼长的矛盾使其发展受限.铜基复合材料可通过强化相提升材料的强度,并且可避免对铜基体产生严重晶格畸变,最大化保证材料的电导率,从而获得优异强阻比的材料,因此铜基复合材料是高性能铜材的一个重要发展方向.本文概述了高性能铜基复合材料的主要制备方法,总结了复合材料增强相及其特点和发展方向.阐述了主要研究进展及其在轨道交通、电工电子、军工方面的应用现状,并对该材料未来的发展方向进行了展望,为高性能铜基复合材料的研究和应用提供参考.

The dominant hydride precipitates have been well demonstrated to follow two types of orientation relationships (ORs) with Ti matrix: OR1 with { 0 0 01 } // { 0 01 } , 1 2?? 10 110 1 2?? 10 110 . Within the grains with special orientations, the complicated interactions of different hydride variants inside Ti-hydride diffusion layer are characterized in this work. For OR1 hydride layer, the orientations of { 10 1?? 0 } plane parallel to the sample surface and a-axis parallel to the normal direction prefer multiple OR1 variants. The orientations favorable for OR2 hydride layer are: { 10 1?? 3 } plane parallel to sample surface corresponding to the layer with one OR2 variant dominated and c-axis parallel to the surface normal with multiple OR2 variant layer preferred. Furthermore, { 10 1?? 2 } extension twins and { 11 2?? 2 } contraction twins are activated to accommodate the OR2 hydride-induced surface expansion and local misfit strain. The stimulation of these two twins is also orientation-dependent: { 10 1?? 2 } and { 11 2?? 2 } twins are observed in the grains with c-axis parallel to and deviated from the surface normal, respectively. The further variant selection for each twin mode is performed through shear accommodation of hydride-twin pairs. ?? 2022 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

A286 is a precipitate-hardened heat-resistant superalloy for use above 700 °C temperature. Precipitation hardening is best reached in homogenized distribution of precipitates such as TiC and η-Ni3Ti phases. To investigate the effect of homogenized melting, A286 alloys with simultaneous variations of C and Ti contents, 0.02C–2.46Ti, 0.04C–2.54Ti, 0.05C–2.58Ti, and 0.06C–2.62Ti, were arc-melted with and without electromagnetic stirring. The stirred samples present round and spherical TiC particles after aging 720 °C/16 h, in contrast to plate- and needle-like TiC particles in the unstirred ones. They also show refined TiC particle mean sizes, about 1.2, 1.3, 1.1, and 1.0 µm, respectively, in the four alloys, compared with 1.3, 1.5, 1.7, 2.0 µm in unstirred samples, where more C and Ti contents induce a stronger stirring refining effect. η-Ni3Ti precipitate mean sizes, about 2.3, 4.9, 4.1 and 6.3 respectively in the four alloys, compared with 5.2, 6.3, 7.8, 6.5 µm in unstirred samples. Consequently strengthening is enhanced in high C–Ti alloys, with the largest yield and ultimate tensile strengths of 533 and 739 MPa in the stirred 0.06Cs–2.62Ti sample in comparison to 500 and 650 MPa. The elongation reaches 20% in this sample, which near doubles that of the unstirred sample. Fractography showed that the transgranular ductile fracture happened due to TiC phases and intergranular brittle fracture happened due to eta phases.

Fe‐based heat‐resistant A286 superalloy is an age‐hardened austenitic stainless steel. Age‐hardening is greatly affected by TiC particles and η ‐Ni 3 Ti phases. Herein, the evolution of TiC and η (hcp‐Ni 3 Ti) precipitations is investigated in six different A286 alloys with simultaneous variations of C and Ti contents, such as 0.00C–2.38Ti, 0.02C–2.46Ti, 0.04C–2.54Ti, 0.05C–2.58Ti, 0.06C–2.62Ti, and 0.08C–2.69Ti wt%. During microstructure evolution from solutioning state (900 °C for 2 h) to aging state (720 °Cfor 16 h), nodular/needle‐like TiC (fcc) and platelet lamellar structures of eta ( η (hcp‐Ni 3 Ti)) phases are observed in the austenitic matrix of superalloys. Statistical analysis of TiC and eta phases after microstructural examination indicates that mean size goes up to 3.3 and 6.8 μm 2 in 0.08C–2.69Ti wt% alloy, respectively. Yield strength and ultimate tensile strength are increased from 350 to 510 MPa and 530 to 650 MPa as a result of the strengthening mechanism of TiC from 0.00C–2.38Ti to 0.08C–2.69Ti wt% alloys, respectively. However, precipitation of these phases leads to brittleness of the alloys and elongation decreases from 20% to 12% with the increment of these phases. The strengthening mechanism is explained by stress–strain curves and fracture topography.

GH2132(A286)是析出强化型铁基高温合金,其含有多种合金化元素,为避免不合适的成分选择导致的综合性能失配,通过重点分析东北特钢提供的产品成分,解析国标成分区间的合理性,本文提出了一个更加合适的新成分标准形式.为此,引入"团簇加连接原子"结构模型,该模型将合金成分的结构载体表述为[中心-第一近邻](连接原子)的团簇成分式形式.首先将合金化元素分为基体Fe、稳定奥氏体的(Ni,Mn)、稳定铁素体的(Cr,Mo,V,Si,Ti,A1)、以及不进入团簇式的(C,P,S,B).通过分析国标规定的成分区间和实际合金成分,指出合金的实际成分区间远小于国标范围,并由16原子的成分式限定:Fe(85～90)+0 25(Ni,Mn)4+0 25(Cr,Mo,V,Si,Ti,Al)3～35.进而揭示了同类元素内部的质量百分比协同变化关系,即 24.6≤Ni+Mn≤28.0 和 17.4≤Cr+0.6Mo+V+1.7Si+1.1Ti+1.8A1≤20.4.由此更合理地限定Mn、Si元素成分区间,并对东北特钢的合金成分提供了改进建议.

Nowadays, electric traction is applied in highspeed trains, and the effects of crosswind increase the instability of the pantograph turbulence, so higher requirements are put forward for the good contact between pantograph and catenary. A new type of pantograph of working height of 2800 mm and a running speed of 400 km/h was taken as the object in this study. Based on the three-dimensional, steady, incompressible N-S equation and k- ω SST (Shear Stress Transport) turbulence model, the variation of aerodynamic force and aerodynamic lift force with different crosswind speed and yaw angle were analyzed. The results show as follows: aerodynamic force and aerodynamic lift force of pantograph increase with increasing crosswind speed. The most dangerous situation of pantograph occurs while the crosswind speed is 30 m/s and the yaw angle is 60°, where the aerodynamic lift force is twice than without crosswind, and the flow field around the pantograph becomes more complicated, resulting in poor current collection between pantograph and catenary. Consequently, high-speed trains should slow down or stop running in the strong crosswind environment.

Precipitation-hardening is achieved in an Fe-Ni-based A286 austenitic superalloy by means of aging process. During the aging process gamma prime phases (γ’), eta (η) phases and TiC phases nucleate in an austenitic matrix of this alloy. In this research, the behavior of η-phases’ precipitation, dissolution and transformation into γ’-phase and γ-matrix, and their consequent effect on high temperature hardness testing and compression is investigated in an Fe-Ni-based alloy. The behavior of phase nucleation is examined after aging at 710 ºC for different lengths of time (1h, 2h, 4h and 8h). Scanning electron microscopy, adjacent with energy dispersive spectroscopy (EDS) and transmission electron microscopy is used to identify the phases ((γ’) Ni3(Al,Ti), eta (η) Ni3Ti and titanium carbides). The nucleation trend is declined with the increase in time of aging and the 8h-aged sample is found to contain the lowest quantity of phases. Then, the 8h-aged sample is investigated for η-phase’ dissolution and transformation behavior. Most of the (η) Ni3Ti phases are transformed into gamma prime phases (γ’) Ni3(Al,Ti) because aluminum is identified in dissolution areas. In (η) Ni3Ti phase dissolution areas, aluminum enhanced up-to 0.37wt.% which is more than double the amount used in composition and titanium increased up-to 4.78wt.%, and nickel increases to more than 27.46 wt.%. Hardness range of the 8h-aged sample is remained from 341 to 265 HV at each temperature from 50 ºC to 700 ºC respectively. Whereas hardness range of 1h-aged sample was between 281 to 215 HV, which is almost 60HV lower than the 8h-aged sample. During compression tests of the aged samples, it is found that the 8h-aged sample showed almost negligible cracks in eta and TiC phases with deformation bands in austenitic matrix. Here, synergic effect of deformation bands and γ’-precipitation enhanced the strengthening of the 8h-aged sample.

Reaching simultaneously high mechanical strength and low electrical resistivity is difficult as both properties are based on similar microstructural mechanisms. In our previous work, a new parameter, the tensile strength-over-electrical resistivity ratio, is proposed to evaluate the matching of the two properties in Cu alloys. A specific ratio of 310 × 108 MPa·Ω−1·m−1, independent of the alloy system and thermal history, is obtained from Cu-Ni-Mo alloys, which actually points to the lower limit of prevailing Cu alloys possessing high strength and low resistivity. The present paper explores the origin of this specific ratio by introducing the dual-phase mechanical model of composite materials, assuming that the precipitate particles are mechanically mixed in the Cu solid solution matrix. The strength and resistivity of an alloy are respectively in series and parallel connections to those of the matrix and the precipitate. After ideally matching the contributions from the matrix and the precipitate, the alloy should at least reach half of the resistivity of pure Cu, i.e., 50%IACS, which is the lower limit for industrially accepted highly conductive Cu alloys. Under this condition, the specific 310 ratio is related to the precipitate-over-matrix ratios for strength and resistivity, which are both two times those of pure Cu.

The Friction-Assisted Lateral Extrusion Process (FALEP) is a severe plastic deformation (SPD) technique for producing metal sheets from bulk metal or powder in one single deformation step at room temperature. In the present work, aluminum Al-1050 was deformed by FALEP. Then, its microstructure was examined by EBSD; the crystallographic texture by X-ray; material strength, ductility, and the Lankford parameter by tensile testing; the latter also by polycrystal plasticity simulations. It is shown that the microstructure was highly refined, with the grain size reduced more than 160 times down to 600 nm under the imposed shear strain of 20. The obtained texture was a characteristic simple shear texture with a shear plane nearly parallel to the plane of the sheet. The yield and ultimate strengths increased by about 10 times and three times, respectively. The Lankford parameter was 1.28, which is very high for aluminum, and due to the specific shear texture, unusual in a sheet. All these exceptional characteristics of Al-1050 were obtained thanks to the efficiency of the FALEP SPD process, which is a promising candidate for industrial applications.

Recently, the advent of dual-phase glass-crystal alloys has attracted the attention of many scholars; since Mg49Cu42Y9 in the Mg-Cu-Y system is reported to exhibit high strength, it opens up a new path for the design of new materials. However, the composition origin of this kind of alloys still puzzles everyone. In the present work, the composition of the alloy Mg49Cu42Y9, which can be considered to be related to the binary eutectic point Cu42Mg58, is thoroughly examined via the cluster-plus-glue-atom model. After strictly following the cluster-based composition analysis procedures, the basic binary eutectic composition Cu42Mg58 can be explained by the dualcluster formula [Mg-Cu4Mg11]Cu2Mg + [Cu-Cu6Mg6]Cu = Cu14Mg19 approximate to Cu42.4Mg57.6, and thus the composition of the dual-phase alloy Mg49Cu42Y9 is explained by replacing three Mg atoms with Y ones, written as Cu14Mg16Y3 approximate to Mg48.48Cu42.42Y9.10. This cluster-based composition analysis method provides a new tool for the dual-phase alloy design.

In High Pressure Shearing (HPS) a flat sample is subjected to large shear strain by displacing one of its flat surfaces with respect to the other under high compressive force. The process is driven by non-sliding friction provided by the large compressive stress. The HPS process was first proposed by Fujioka and Horita [Materials transactions, 50 (2009) 930–933], and was applied to aluminum strips; upscaling was also developed. In the present work we introduce a modified version of HPS where the compression strain is relevant, so the new process is called High Pressure Compressive Shearing (HPCS). In HPCS, the experiments are conducted similarly to HPS but with the addition of a confining-pressure and more compression strain to increase the shear strain. This paper presents the mechanical analysis of stress and strain states during HPCS and demonstrates in situ measurements of stress-strain relations in ARMCO® steel subject to HPCS at room temperature up to an equivalent strain of 33.3. The strain hardening characteristics, the texture and the microstructure were analyzed. It has been shown that compression during HPCS results in a non-hydrostatic stress state and that ultimate steady state of grain fragmentation can be readily reached by HPCS.

Low electrical resistivity and high strength are a basic requirements for copper alloys.However,it has been widely known that these two properties are contradictory to each other:high electrical resistivity means extensive electron scattering by obstacles in the alloy,which in turn blocks dislocation movement to enhance mechanical strength.That is to say,any increase in strength necessarily brings about an increase in electrical resistivity.Essentially,strength and electrical resistivity are coupled in metal alloy as both are issued from a similar microstructural mechanism. That is why it is generally difficult to evaluate these alloys comprehensively and to select the materials appropriately. The present work addresses this fundamental problem by analyzing the dependence of hardness (in relation to strength) and electrical resistivity on solute content for deliberately designed ternary[Moy/(y+ 12)Ni12/(y+12)]xCu100-x alloys (at.%),where x=0.3-15.0 is the total solute content,y=0.5-6.0 is the ratio between Mo and Ni.The Mo-centered and Ni-nearest-neighbored[Mo1-Ni12]cluster structure are used to construct a short-range-order structure model of solid solution.The cluster[Mo1-Ni12]in solution enhances the strength,without increasing the electrical resistivity much,for the solutes are organized into cluster-type local atomic aggregates that reduce the dislocation mobility more strongly than electron scattering.The short-range-order structure has an essentially identical function for strength and electrical resistivity. In this solution state,both hardness and resistivity increase linearly with solute content increasing.When the solute constituents do not meet the requirement for ideal solution,i.e.,Mo-Ni ratio exceeds 1/12,the maximum value that the cluster[Mo1-Ni12]can accommodate,the solid solution should be destabilized and precipitation should occur,such as Mo precipitation in this case.The deviation from the linear change of resistivity and strength with solute content are caused by different alloy states,that is,solid solution and precipitation,which contribute to the resistivity and strength differently.Here we define a new term,the ratio of residual tensile strength to residual electrical resistivity,i.e.the “strength/resistivity ratio” in short,which represents an essential property of the alloy system.This ratio is 7×108 MPa/Ω· m) for the Cu-Ni-Mo alloy in complete solid solution state,and it is in a range of (310-490) 108 MPa/Ω·m) for the Cu-Ni-Mo alloys in a fully precipitation state (i.e.,most of Mo solute atoms precipitate out of the Cu matrix). Finally this new parameter is applied to the classification of common copper industrial alloys for the purpose of laying the basis for material selection.It is found that the strength/resistivity ratio of 310 effectively marks the boundary between the fully precipitated state and precipitation plus solution state.Using this criterion,it is concluded that alloys based on Cu-(Cr,Zr,Mg,Ag,Cd) are suitable for high-strength and high-conductivity applications.However,alloys based on binary systems Cu-(Be,Ni,Sn,Fe,Zn,Ti,Al) cannot realize the same purpose.The finding of the line dividing the characteristic properties of alloy having a strength-resistivity-ratio of 310 provides a key quantitative basis for comprehensively evaluating the alloy performance,which can effectively guide material selection and development of high strength and high conductivity copper alloys.

Employing a recent modeling scheme for grain boundary sliding [Zhao et al. Adv. Eng. Mater. 2017, doi:10.1002/adem.201700212], crystallographic textures were simulated for nanocrystalline fcc metals deformed in shear compression. It is shown that, as grain boundary sliding increases, the texture strength decreases while the signature of the texture type remains the same. Grain boundary sliding affects the texture components differently with respect to intensity and angular position. A comparison of a simulation and an experiment on a Pd–10 atom % Au alloy with a 15 nm grain size reveals that, at room temperature, the predominant deformation mode is grain boundary sliding contributing to strain by about 60%.

A new crystal plasticity model is presented to account for the effect of grain boundary sliding (GBS) on texture evolution during large plastic deformation of nanocrystalline materials. In the model, 12 grain boundaries are assigned for each grain and their sliding rates are calculated using Newtonian viscoplasticity. The lattice rotation of the grain interior is computed by taking into account the deformation field modification produced by GBS. The model is employed for predicting the texture evolution in a nanocrystalline Pd–10 at%Au alloy subjected to large strain simple shear, up to a shear strain of 16.8. Two main texture effects due to increasing GBS are identified: high reduction in texture intensity, and tilts of the texture components from their ideal orientations. In the alloy considered, the contribution of GBS to the total strain is identified to be about 30%.

Strength and electrical resistivity are coupled in metal alloys as both are based upon a similar microstructure mechanism, but the quantitative relationship between them is not known due to the complex microstructures involved. The present work analyzes the dependence of hardness and electrical resistivity on solute contents for ternary [Moy/(y+12)Ni12/(y+12)]xCu100−x alloys (at.%), where x = 0.3–15.0 is the total solute content and y = 0.5–6.0 the ratio between Mo and Ni. The alloys are designed following the cluster-plus-glue-atom model to reach three distinct structural states, i.e., cluster solution state (y = 1), where Mo is dissolved via a chemical short-range order characterized by Mo-centered and Ni-nearest-neighbored [Mo1-Ni12] cluster, cluster solution state plus extra Ni solution (y < 1), and a cluster solution state plus extra Mo in precipitation (y > 1). The measured electrical resistivity and microhardness data are correlated with these three structural states to reveal the property dependencies on solute contents. The cluster solution enhances the strength, without causing much increase in the electrical resistivity, as the solutes are organized into cluster-type local atomic aggregates that decrease dislocation mobility more strongly than electron scattering. Analogous to residual resistivity ρR, which indicates the change of resistivity with reference to pure Cu, residual microhardness HR and residual lattice constant aR are also defined. For the ideal cluster solution state (y = 1, Mo/Ni = 1/12), the mentioned three parameters are correlated with the total solute content x by ρR = 1.08·x (10−8 Ω m), HR = 1.50·x (Kgf mm−2), and aR = − 1.08·x (10−4 nm). From these, ρR = 0.72HR = − aR. Such simple relationships indicate that resistivity and strength are dependent on the same cluster-type solution mechanism and can be a good reference for evaluating strength and resistivity performance of Cu alloys.

While severe plastic deformation (SPD) on bulk samples has been widely applied for modifying the H-sorption properties, there has been little attention towards the use of SPD on powder materials. In this context, the aim of the present work was to compare the H-storage properties of high-pressure torsion (HPT) consolidated products obtained from two distinct Mg powder precursors: atomized micro-sized and condensed ultrafine powder particles. The results showed that the nature of the initial powder precursor had a pronounced effect on the H-sorption behavior. The HPT product obtained from the condensed ultrafine powder showed faster absorption kinetics than the consolidated product obtained from the atomized powder. However, the HPT product obtained from atomized powder could absorb more hydrogen and showed faster desorption kinetics corresponding to a lower activation energy. These results are discussed by taking into account the effectiveness of the HPT process to refine the grain sizes and differences in the dispersion of fine MgO oxide particles.