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The Ce2−xMMxCo17 (x = 0.0, 0.3, 0.5, 0.8) powders were manufactured by vacuum melting and high-energy ball milling method so as to demonstrate the effect of Misch-metal (MM) (La-25.87 wt%, Ce-53.56 wt%, Pr-6.59 wt%, Nd-13.98 wt%) content on microwave absorption of Ce2Co17 alloy. The influences of MM content on the microstructure, saturation magnetization, electromagnetic parameters, and the microwave absorption performance of Ce2Co17 powders were investigated by the corresponding equipment. The results show that the particle size tends to increase, the reflectivity value of Ce2−xMMxCo17(x = 0.0, 0.3, 0.5, 0.8) alloy increases first and then decreases and the minimum absorption peak frequency is shifted to the lower frequency band with the increase of MM content. Flaky Ce1.7MM0.3Co17 demonstrated the best absorption performance where the RLmin reached − 40.17 dB at 8.72 GHz with an efficient bandwidth of 3.2 GHz (RL

The effects of small amounts of Ce-rich misch metal (Mm: 0.5, 1.0 and 2.0 wt.%) addition on the microstructure and tensile properties of as-cast Mg-7Al-3Sn-1Zn wt.% (ATZ731) alloy have been investigated. The addition of Mm restricts the formation of the Mg17Al12 phase but greatly promotes the Al4Mm phase. The proper Mm addition enhances the strength and ductility of ATZ731 alloys at both room temperature (RT) and 175 °C. ATZ731 alloys with 1.0 wt.% Mm addition exhibit an advantageous combination strength and ductility, with the ultimate tensile strength (UTS), 0.2% yield strength (YS) and elongation to failure (Ef) at 175 °C of ~148 MPa, ~102 MPa and ~28%, improved by ~14.7%, ~24.3% and ~53.8%, respectively, compared to those of ATZ731 alloy. This enhancement is primarily owing to the refined microstructures and the high thermal stability of Al4Mm at the elevated temperature in contrast with that of the Mg17Al12 phase. The fracture modes are also discussed.

Misch metal (Mm), consisting of Ce and La, was added to Ti–45Al–3Mo–2Nb alloys in order to investigate phase transformation and microstructural changes. The pseudo-binary phase diagram was estimated via PANDAT software™. The addition of Mm caused a decrease in both the fractions of α2/γ lamella and the β0 phase, and served as an important factor for a collapse of lamellar structures. In addition, Mm significantly decreased the colony size of the alloy, resulting in an increase in high-temperature tensile yield strength of ~ 40% for the alloys with 0.3 at% Mm at 800 °C. It appears that the addition of Mm affects the phase stability and increase the proportion of the γ phase. The microstructural changes, with respect to Mm additions, were discussed in terms of structural observations during isothermal heat treatments.

The authorsr works studying the hydrogen sorption properties of the magnesium-based materials are reviewed. The objects of the studies were highly dispersed powders of Mg—La—Ni and Mg—Mm—Ni alloys (Mm is misch metal) of the ternary eutectic, composites of magnesium alloys with extended carbon nanostructures, and composites of magnesium hydride with lanthanide oxides. The positive effect of lanthanide oxide additives on the process of hydro-gen desorption from magnesium hydride and the role of carbon nanofibers in these processes carried out at room temperatures are discussed.

Phase stability of Al-RE intermetallic compounds is crucial particularly for high temperature mechanical properties of Mg–Al–RE based alloys as well as the possibility of their commercial applications. For a long time, a controversial issue exists concerning whether Al 11 RE 3 phase in heat-resistant Mg–Al–RE based alloys decomposes into Al 2 RE and Al when treated at high temperatures. Herein, we performed a systematically study to the relative phase stability of all Al 11 RE 3 with single RE element compared with Al 2 RE at 0–1000 K using the state-of-the-art first-principles density functional calculation method. The results indicate that Al 11 RE 3 phases with RE = La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb are highly stable while those with RE = Ho, Er, Tm, Lu, Y, and Sc are always instable compared with the Al + Al 2 RE two-phase equilibrium at temperatures lower than 1000 K. These calculations suggest that Al 11 RE 3 phase in the Mg–Al–RE based alloys with Ce-rich misch metal or mixed RE elements would decompose into Al 2 RE and Al due to the instable Al 11 RE 3 components, then decreased the alloy’s high temperature performances. The present work also provides important guidance for future optimization design of heat-resistant magnesium alloys.

The thermal conductivities of quaternary Mg-Zn-Ca-MM alloys have been investigated by evaluating the effect of MM on Mg-4Zn-0.5Ca alloys, with an emphasis to develop a new Mg alloy without compromising thermal conductivity, process-ability and mechanical property. As a result, the thermal conductivity of 0.5 wt.% MM-added Mg-Zn-Ca alloy was almost same as that of MM-free Mg-Zn-Ca alloy. However, with further increasing MM contents, thermal conductivities of MM-added alloys decreased. The tensile yield strength was improved with increasing MM contents. In addition, the average spiral flow lengths of Mg-Zn-Ca-xMM alloys were almost same levels with Mg-Zn-Ca alloy.

In order to reduce the RE-Fe-B material cost and balance the utilization of rare earth sources, misch metal substitution for Nd in the sintered magnet becomes of many interests. Under the process of fabricating high magnetic properties magnet, the strip-casting (SC) technique plays a key role, a series of rapidly solidified [(PrNd)1-xMMx]13.8FebalCo0.5Cu0.1Al0.6Ga0.07B5.9 (x = 0 ~ 1.00) (MM, Misch Metal) strips were manufactured. Subsequently, the phase constitution, microstructure and the intrinsic magnetic properties were measured. There are always stable RE2Fe14B phase in the strips with MM, which is similar to Nd-Fe-B strip. Whereas, when x ≥ 0.50, there exists REFe2 phase inevitably, and the amount of REFe2 phase gradually increases with increasing MM content. Magnetic measurements indicated that intrinsic magnetic properties, such as the saturation magnetization Ms and magneto-anisotropy field HA, deteriorate gradually by substituting PrNd with MM except for x = 0.35. For x = 0.35, the abnormal phenomenon is ascribed to Ce valence shifting toward +3 that is caused by lattice expanding. In addition, when x ≥ 0.50, La and Ce is prior to aggregate in the RE-rich phase clusters, and the content of Fe rises with the increase of MM, moreover, the interfaces between of RE2Fe14B phase and RE-rich phase become indistinct.

The phase structure, magnetic properties, magnetocaloric effect (MCE) and relative cooling power (RCP) of MM2Fe17-xSix (x = 0–1.5) compounds were studied. The phase transition temperature was increased from 238 K to 366 K with the increase of Si content. The X-ray diffraction (XRD) patterns indicate that the MM2Fe17-xSix (x = 0–1.5) compounds crystallize primarily in a rhombohedral phase with Th2Zn17 type crystal structure coexisting with a small amount of the precipitation α-Fe phase. These results are reinforced by backscattered scanning electron microscope (SEM) images and electron energy dispersive X-ray spectroscopy (EDX) analysis. The maximum values of magnetic entropy change (ΔSM) for MM2Fe17-xSix (x = 0, 0.3, 0.6, 1.0) compounds are −2.1 J kg−1K−1, −1.3 J kg−1K−1, −1.5 J kg−1K−1, −1.8 J kg−1K−1 for field change of 0–2 T and −4.0 J kg−1K−1, −2.7 J kg−1K−1, −3.1 J kg−1K−1, −3.5 J kg−1K−1 for field change of 0–5 T. The estimated RCP values are larger than 100 J kg-1 and 350 J kg-1 for the field change of 0–2 T and 0–5 T, respectively. The working temperature range δTFWHM is larger than 50 K and 100 K with the field changes of 0–2 T and 0–5 T, respectively. The temperature range and RCP values are comparable to the second-order phase transition (SOPT) materials R2Fe17 (R = Pr, Nd) and Gd, but the cost of MM2Fe17-xSix is only about 25% and 10% compared with R2Fe17 (R = Pr, Nd) and Gd, respectively.

In this study, the structural, magnetic and magnetocaloric effects (MCE) of misch-metal MM2Fe17−xAlx (0 ≤ x ≤ 2) compounds are investigated. The XRD patterns indicate that all the samples crystallize primarily in a rhombohedral Th2Zn17 type crystal structure coexisting with a small amount of precipitation phase α-Fe. The lattice parameters and the Curie temperature (TC) increase linearly with the increase of Al content. This allows the MM2Fe17−xAlx compounds to achieve magnetic refrigeration over the entire room temperature range. The maximum values of entropy changes (ΔSM) for MM2Fe17−xAlx (x = 0, 0.5, 1 and 1.5) compounds with a magnetic field variation of 0–2 T and 0–5 T are determined to be −2.1 J Kg-1 K−1, −1.3 J Kg-1 K−1, −1.9 J Kg-1 K−1, 1.9 J Kg-1 K−1 and −4.0 J Kg-1 K−1, −2.7 J Kg-1 K−1, −3.5 J Kg-1 K−1, −3.5 J Kg-1 K−1, respectively. The relative cooling power (RCP) for all the studied compounds is larger than 90 and 270 Jkg−1 while the full-width half maxima (δTFWHM) is larger than 60 K and 100 K with the field changes of 0–2 T and 0–5 T, respectively. These results indicate that MM2Fe17−xAlx (0 ≤ x ≤ 2) compounds could have higher magnetocaloric cost-performance comparable to the room-temperature magnetic refrigeration materials R2Fe17 (R = Pr, Nd) and Gd with the second-order phase transition (SOPT).

Magnetic properties and the magnetocaloric effect (MCE) of the RSi (R = Ce, Pr, Nd) compounds made of Misch metal (MM) are investigated. Two transitions are found at 12 K and 38 K. Field variation generated large MCE and two peaks are found in the magnetic entropy change (ΔS) curves, which correspond to the two transition temperatures. The maximum values of the magnetic entropy changes (ΔS) are found to be −5.1 J/(kg⋅K) and −9.3 J/(kg⋅K) for the field ranges of 0–2 T and 0–5 T, respectively. The large ΔS as well as ultra-low price of MM make (MM)Si a competitive magnetic refrigerant candidate for low temperature in Eriksson cycle.

The misch-metal (MM) containing Ce, La, Pr, and Nd are much cheaper than pure Nd or Pr-Nd alloys.

The static and dynamic pressure-concentration isotherms (PCIs) of MmNi5-xAlx (x = 0, 0.3, 0.5 and 0.8) hydrides were measured at different temperatures using volumetric method. The effect of Al substitution on PCI and thermodynamic properties were studied. The plateau pressure and maximum hydrogen storage capacity decreased with Al content whereas reaction enthalpy increased. The plateau pressure, plateau slope and hysteresis effect was observed more for dynamic PCIs compared to static PCIs. Different mathematical models used for metal hydride-based thermodynamic devices simulation are compared to select suitable model for static and dynamic PCI simulation of MmNi5-based hydrides. Few important physical coefficients (partial molar volume, reaction enthalpy, reaction entropy, etc.) useful for development of thermodynamic devices were estimated. A relation has been proposed to correlate aluminium content and physical coefficients for the prediction of unknown PCI. The simulated and experimental PCIs were found matching closely for both static and dynamic conditions. � 2014 Hydrogen Energy Publications, LLC. All rights reserved.

The notch tensile behavior of extruded Mg–6RY–4Zn and Mg–9RY–4Zn (RY: Y-rich misch metal) alloys containing long period stacking ordered (LPSO) phase tested from room temperature to 250 °C was investigated. LPSO long-strips crack more severely in notch samples compared with that in smooth samples. The UTS values are above 300 MPa and the notch sensitivity ratio (NSR) values are larger than 1 in both alloys because the severe crack of LPSO phase costs more energy in notch samples. Furthermore, the NSR value rises with increasing the RY content or elevating the test temperature. The strengthening effect of LPSO phase is more remarkable at high temperatures. The notch leads the fracture mode of the two alloys changing from ductile fracture to brittle fracture. Designing complex shape components should consider the NSR and plasticity of Mg–Y–Zn alloys together.

In this manuscript, the estimation of thermochemical properties such as enthalpy of formation (ΔH) and entropy of formation (ΔS) during hydriding and dehydriding reactions of three titanium (Ti), five misch metal (Mm) and eight lanthanum (La) based metal hydride alloys are presented. van't Hoff plots of the selected metal hydride alloys are constructed using the Pressure–Concentration–Temperature (PCT) characteristics measured at different operating temperatures. Reaction enthalpies during hydriding and dehydriding processes are expressed as a function of hydrogen storage capacity by a polynomial equation of order three. The average enthalpy of formation during dehydriding process of the investigated titanium and lanthanum based alloys are about 3–18% higher than their respective hydriding enthalpies. While, dehydriding enthalpies of LmNi4.49Al0.205Mn0.205Co0.1 and MmNi4.85Al0.15 are about 26.5% and 40% higher than their respective hydriding enthalpies. The variation in reaction enthalpies during the initial and final stages of hydriding process of titanium based alloys is in the range of 7–9%, while the respective ranges for misch metal and lanthanum based alloys are about 3–7.5% and 2.1–8.5%, respectively.

Hydrogenated Mg 3 Mm (where Mm denotes La-rich and Ce-rich misch metal) has been identified as an excellent hydrolysis material for the first time. Hydrolysis of the as-hydrogenated Mg 3 Mm produced 695 mL g −1 hydrogen in 5 min, 828 mL g −1 hydrogen in 15 min, and the highest hydrogen yield reached 9.79 wt.% at 298 K. Compared to hydrogenated Mg 3 La, Mg 3 Ce, Mg 3 Pr, and Mg 3 Nd, hydrogenated Mg 3 Mm displayed the fastest hydrolysis rate due to mutual catalysis of LaH 3 , CeH 3 , PrH 3 , and Nd 2 H 5 . The hydrolysis mechanisms of hydrogenated Mg 3 RE are also discussed herein.

Present investigation deals with the wear behaviour of conventional cast Mg–5%Sn and Mg– 5%Sn–2%Mm (Mm is misch metal) (wt.%) alloys studied through pin-on-disc wear experiments at four different loading conditions under ambient temperature. This study reports the effects of external applied load on the dry sliding wear rate and co-efficient of friction of both the alloys. It has been investigated that the volumetric wear loss increases with increasing applied load. It has also been found that the wear rate of Mg–5%Sn–2%Mm alloy is less than that of Mg–5%Sn alloy. The wear mechanism has also been studied through extensive scanning electron microscopy imaging. It has been investigated that wear occurs by delamination of flakes and ploughing (i.e., asperities).

The structure and gaseous phase hydrogen storage characteristics of a series of as-cast Nd(NiCoAlMn) 5 alloys were studied. Without an annealing treatment, the main phase of these alloys was NdNi 5 -structured with Nd 2 Ni 7 (may include Nd 5 Ni 19 and NdNi 4 ) as the main secondary phase. In most of the alloys, single-plateau pressure–concentration–temperature isotherms were observed due to the expansion of the unit cells brought on by additions of larger B-elements into the alloys. As the amount of replacement element increased, both the equilibrium plateau pressure and hydrogen storage capability reduced. A proper guideline for the amounts of Al- and Mn-additions was established for battery application: Co = 8 at.%, 8 at.% ⩽ Mn + Al ⩽ 14 at.%. In the half-cell electrochemical measurements, the capacities of these un-annealed Nd-based AB 5 alloys were lower than those of the commercially available misch metal (Mm)-based AB 5 alloy but showed an advantage in high-rate dischargeability. In the sealed cell experiments, some of the Nd-based AB 5 alloys showed superior high-rate and charge-retention performance compared to the Mm-based AB 5 alloy. The abundance of secondary phase may have played an important role in influencing the high-rate performance. The alloy with the composition of Nd 17 Co 8 Al 6 Mn 8 Ni 61 showed the best overall electrochemical performance and was recommended for further study.

Nd-Fe-B permanent magnets have been widely used in many fields because of their outstanding magnetic properties[1]. However, Pr,Nd and Dy are now considered to be critical elements due to an increasing demand. Therefore, researchs on substitution of Pr-Nd by Ce or misch-metal alloys (MM) are attracting renewed attention because of their potential applications in permanent magnets[2] [3]. The intrinsic magnetic properties of La2Fe14B and Ce2Fe14B are far inferior to those of Nd2Fe14B, so it is hard to acheive high performance R-Fe-B magnets based on misch-metal which contains a majority of La and Ce elements through conventional methods.

Rare earth (RE)-based permanent magnets with high energy product are at the core of modern technology; they enable efficient electric engines and power generation from renewable sources. The urgent issue facing these materials is the resource risk. RE based ores can be efficiently retrieved only in a limited number of extraction sites, making such raw materials vulnerable to wild cost fluctuations. On top of this, a growing use of RE in various hi-tech applications is expected to rapidly increase their market demand. In this contribution we will report on RE intermetallic MM2Fe14B compounds, in which a blend of 66 at.% Ce and 33 at.% La Misch-Metal (MM) has been used as the RE element. In this way it is possible to maintain the 2:14:i type of crystal structure, which provides a strong lattice contribution to the onset of uniaxial magnetic anisotropy, while using the least expensive and most abundant REs. Melt spun ribbons have been prepared with different doping elements, both magnetic and non-magnetic (Cu, Co, Zr, Ga). Compositions with excess MM prevented the formation of the competitive Ce2Fe soft magnetic phase. Nanocrystalline and amorphous ribbons have been cast by melt spinning at different wheel speeds; heat treatments in the range 670-1070 K ensured homogenization and crystal growth. Heat treated samples show hard magnetic character, with saturation magnetization and coercivity dependent on composition: Cu doping is detrimental on both the coercivity and saturation magnetization. Both Zr and Co addition improve saturation magnetization at the expenses of coercivity, while Ga doping enhance both coercivity and magnetization. The maximum energy product in ribbons increases from 4.3 MGOe for (Ce12La6.5)Fe75.5B6 up to 5.5 MGOe for (Ce12La6.5)Fe74.5GaB6. We will present a thorough magnetic and structural characterization, including magnetic anisotropy measurements directly performed on polycrystalline ribbons by means of the singular point detection technique in pulsed magnetic field up to 20 T [1,2]. The results and possible improvement strategies will be discussed by taking into account intrinsic and extrinsic effects. Work was supported by Ford Motor Company and by the EU funded project PIRSES-GA-2011-295190 [1] G. Asti and S. Rinaldi Phys. Rev. Lett. 28, 1584-15

This paper describes a set of experiments with misch metal and rare earth silicide additions in 1010 and 1030 steel to determine whether grain refinement occurs. Target rare earth (RE) contents of 0.1 and 0.2% were employed. After melting, the desired RE addition was added during tapping and then poured into green sand molds. The resulting test plates were then sectioned for tensile and metallographic testing. Yield strength increased for several of the 1010 and 1030 samples. The increase in yield strength correlated with a reduction in grain size. A dramatic increase in percent elongation was also observed in the 1010 sample with the smallest grain size. Electron microscopy found complex RE oxides. These oxides appear to act as heterogeneous nuclei. When they were coated with another slag, the grain size and mechanical properties were similar to the baseline material in both the 1010 and 1030.

The as-cast Mg-14Li-3Al-(0-0.9)RE alloys were prepared with vacuum melting method, then processed by hot extrusion. The microstructure and tensile properties were investigated. The results show that both addition of RE and extrusion deformation can refine the grain size. Al3La compounds are formed with addition of La-rich misch metal. The as-extruded Mg-14Li-3Al-0.6RE alloy obtains the finest grain size (4.28 μm) and the highest mechanical properties (σb=222.75 MPa, δ=23.8%), which is related to the grain refinement and the formation of Al3La.

The effect of misch metal and silicium additions to AZ31 magnesium alloy on the microstructure was investigated in this study. The results showed that needle shape Al11RE3 phase and polygonal type Mg2Si phase formed when misch metal and silicium were added to AZ31 magnesium alloy, which providing refined microstructure compared to AZ31 magnesium alloy. The coarse Chinese script type Mg2Si phase is not found. In addition, the β-Mg17Al12 phase completely divorced and formed many white particle phase. Based on the present experiment , the optimal additions of RE and Si were 0.5 wt% and 0.4 wt%, respectively.

We analyzed the reaction between a rare earth element and ferritic-martensitic stainless steel in order to evaluate the role of the rare earth element in the fuel cladding chemical interaction (FCCI). A diffusion couple test between Misch metal (70Ce-30La) and 9Cr-2W (Gr.92) steel at both 660 °C and 800 °C was conducted, and a microstructural analysis was carried out. The result showed that Fe in the Gr.92 material and Ce in the Misch metal mainly diffused and reacted to form intermetallic compounds, namely Fe2Ce and Fe17Ce phases, above 660 °C, whereas La hardly diffused or reacted in the Gr.92 material. In the specimen tested at 660 °C, the Fe diffused outside of the clad interface so that Cr-rich precipitated beneath the clad interface. In the specimen tested at 800 °C, a local reaction caused by the eutectic transformation of the (Fe,Cr)17Ce phase resulted in a local penetration across the clad.