La Addition Research Articles

Effects of La addition on the microstructure, corrosion behavior and discharge performance of the as-casted AP63 anodes for Mg–air batteries

Effects of La addition on the microstructure, corrosion behavior and discharge performance of the as-casted AP63 anodes for Mg–air batteries

Application of Lanthanum at the Heading Stage Effectively Suppresses Cadmium Accumulation in Wheat Grains by Downregulating the Expression of TaZIP7 to Increase Cadmium Retention in Nodes.

Reducing cadmium (Cd) accumulation in wheat is an effective way to decrease the potential threats of Cd to human health. The application of lanthanum (La) in agricultural fields is eliciting extensive attention due to its beneficial effects on improving yields and inhibiting Cd accumulation in edible parts of crops. However, the potential mechanism of La-restricted Cd accumulation in crop grains is not entirely understood. Here, we investigated the effects of La and Cd accumulation in wheat grains by implementing application at the shooting and heading stages. Some associated mechanisms were explored. Results showed that La application at the shooting and heading stages considerably promoted the thousand-grain weight. La application at the shooting and heading stages increased Cd accumulation in the first node beneath the panicle (N1) but reduced Cd levels in the other tissues. La application at the heading stage exerted greater effects on Cd storage in N1 while reducing Cd concentrations in the other tissues compared with La application at the shooting stage. La addition substantially decreased the translocation of Cd from the lower nodes to the upper internodes, but increased Cd translocation from the lower internodes to the upper nodes. The expression of TaZIP7 in N1 was downregulated by La treatment. These results suggest that the effective reduction in Cd in wheat grains by La application at the heading stage is probably a consequence of the successful promotion of Cd storage in nodes by downregulating the expression of TaZIP7 during the grain-filling stage, thereby hindering the redirection Cd from nodes to grains.

Effect of La on Microstructure, Mechanical Properties and Friction Behavior of In Situ Synthesized TiB2/6061 Composites

In situ synthesized 3 wt.%TiB2/6061 composites with different La contents were fabricated by an Al-K2TiF6-KBF4 system at 850 °C with ball milling and stirring casting. The effects of La content (0 wt.%, 0.1 wt.%, 0.3 wt.%, 0.5 wt.%) on the microstructures and mechanical properties of the composites at room temperature were investigated. The results showed that the addition of La could refine α-Al grains and modify the morphology of TiB2 particles significantly. In 0.3 wt.%La-3 wt.%TiB2/6061 composites, there are chamfering planes on the surface of TiB2 particles, which are caused by the adsorption of La on the {112¯0}, {12¯12} and {101¯1} crystal planes. The values of YS, UTS and EL of the composites with 0.3 wt.% La were 216.8 MPa, 273.0 MPa and 11.2%, which were 69.2%, 34.8% and 5.7% higher than those of the 3 wt.%TiB2/6061 composites. The improvement of mechanical properties was mainly attributed to the grain refinement, distributed particles and transformation of particle morphology. In friction behavior, 0.3 wt.%La-3 wt.%TiB2/6061 composites have the best wear resistance properties with the smallest and shallowest grooves on the surface after wearing. The main mechanisms of the composites are adhesive wear and abrasive wear. In summary, the best content of La addition in 3 wt.%TiB2/6061 composites is 0.3 wt.%.

La drives the remarkable strength enhancement of the Cu-Cr-Zr alloy through traditional thermo-mechanical treatment

The Cu-1Cr-0.1Zr alloy with different La addition (0 %, 0.07 % and 0.14 wt%) was processed using industry suitable two-step cold rolling and aging treatment to achieve superior strength and electrical conductivity. The role of La addition on the microstructure evolution and comprehensive properties of the Cu-1Cr-0.1Zr alloy is investigated during the second rolling and subsequent aging stages. During pre-aging process, the presence of La in the Cu-1Cr-0.1Zr-0.07La alloy led to formation of smaller precipitate sizes compared to La-free Cu-1Cr-0.1Zr alloy. This facilitates a stronger cut interaction between dislocations and precipitates during secondary rolling process, which promotes the redissolution of precipitates into Cu matrix and thus results in a larger decline of 44.72 % ICAS for the electrical conductivity of Cu-1Cr-0.1Zr-0.07La alloy. After post-aging treatment, precipitates are newly formed with increased number and refined size of Cr precipitates with maintaining a coherent relationship with the matrix. Besides, the addition of La promotes Cr-rich phase precipitation and dislocation accumulation. Resultantly, remarkable increase in tensile strength by 11 % with the addition of 0.07wt%La. While, the 0.14La added alloy exhibits comprehensive properties of tensile strength 600 MPa and electrical conductivity 80.08 %IACS after aging at 440 °C for 180 min. The increase in strength was primarily attributed to precipitation strengthening and dislocation strengthening. This work provides new kinds of Cu-1Cr-0.1Zr alloy and industrial suitable thermo-mechanical treatment for fabricating high performance cooper alloy sheets.

Investigation of the Effects of La Addition on Microstructure and Friction Performance of High-Speed Steel Rolls

Investigation of the Effects of La Addition on Microstructure and Friction Performance of High-Speed Steel Rolls

Impact of Aging Time on the Morphological, Mechanical, and Tribological Behavior of Al-6.6Si-0.2Mg-0.2La Hypoeutectic Alloy

Abstract The present work aimed to examine the influence of Lanthanum (La) on the morphological, mechanical, and tribological characteristics of Al-6.6Si-0.2Mg alloy. The alloy specimens were exposed to an aging process at 180°C for 8h and 12h. The morphological transformation due to La addition was analysed with an emphasis on altering primary and eutectic silicon morphology, grain refinement, and intermetallic phase distribution. The experimental investigations were carried out using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) whereas the hardness and wear characteristics were analyzed by performing Vickers microhardness and pin-on-disc tests. The obtained results demonstrated that lanthanum inclusion causes significant microstructure refinement, resulting in enhancing the microhardness by up to 60 %, proliferating the tensile characteristics by 70%, and aiding in improving the tribological characteristics of the Al-Si-Mg alloy. The results provide a clearer understanding of the alloy modification process and offer valuable insights for enhancing the performance of Al-Si-Mg aluminium alloys in automotive and aerospace applications.

Mechanisms of Lanthanum-mediated mitigation of salt stress in soybean (Glycine max L.).

Salinity is considered one of the abiotic stresses that have the greatest impact on soybean production worldwide. Lanthanum (La) is a rare earth element that can reduce adverse conditions on plant growth and productivity. However, the regulatory mechanism of La-mediated plant response to salt stress has been poorly studied, particularly in soybeans. Therefore, our study investigated the mechanisms of La-mediated salt stress alleviation from the perspectives of the antioxidant system, subcellular structure, and metabolomics responses. The results indicated that salt stress altered plant morphology and biomass, resulting in an increase in peroxidation, inhibition of photosynthesis, and damage to leaf structure. Exogenous La application effectively promoted the activity of superoxide dismutase (SOD) and peroxidase (POD), as well as the soluble protein content, while decreasing the Na+ content and Na+/K+ ratio in roots and leaves, and reducing oxidative damage. Moreover, transmission electron microscopy (TEM) demonstrated that La prevented the disintegration of chloroplasts. Fourier-transform infrared spectroscopy (FTIR) analysis further confirmed that La addition mitigated the decline in protein, carbohydrates, and pectin levels in the leaves. Lanthanum decreased the leaf flavonoid content and synthesis by inhibiting the content of key substances in the phenylalanine metabolism pathway during NaCl exposure. Collectively, our research indicates that La reduces cell damage by regulating the antioxidant system and secondary metabolite synthesis, which are important mechanisms for the adaptive response of soybean leaves, thereby improving the salt tolerance of soybeans.

Influence of La additions on solidification and microstructure in the as-cast state of the aluminium alloy EN AW-7175

Influence of La additions on solidification and microstructure in the as-cast state of the aluminium alloy EN AW-7175

Synthesis, characterization, and catalytic performance of Ni supported on sustainable POFA-derived SBA-15 for hydrogen-rich syngas from CO2 reforming of methane

Palm Oil Fuel Ash (POFA) is massively produced by numerous palm oil mills worldwide, creating an environmental waste disposal problem. Notably, POFA serves as a cost-effective alternative silica source instead of the expensive tetraethyl orthosilicate (TEOS). This research focused on synthesizing SBA-15 from POFA waste and examining the effect of promoters on POFA-derived SBA-15-supported Ni-based catalysts. The 10 wt% Ni/SBA-15-POFA catalyst was sequentially impregnated with promoters having 1 wt% loading of Zr, Ce, La, and Cr. The catalysts were tested for CO2 methane reforming (CMR) at 800 °C for 8 hours while maintaining a stoichiometric feed ratio. Various characterization techniques, including XRD, FESEM, XPS, H2-TPR, CO2-TPD, and BET analysis were employed to assess the catalyst physicochemical properties. The addition of promoter changed the properties of catalyst. Except for Cr-promoted catalyst, the addition of promoters positively impacted catalytic performance, activity, and stability. XRD analysis showed that Cr addition had detrimental effects on the crystallite structure of the Ni/SBA-15-POFA catalyst. In contrast, Zr, Ce, and La additions significantly reduced the crystallite size and improved active metal dispersion. Overall, the Zr-promoted catalyst exhibited the best performance in terms of activity and stability, with a CH4 conversion of 90 % and CO2 conversion of 94.4 %. The spent catalyst characterization, including XRD, FESEM, O2-TPO, and RAMAN, showed that promoter addition significantly reduced carbon deposition. The stable and superior perfromance of Zr-promoted catalyst was attributed to the production of MWCNTs. Conversely, the rapid deactivation of the unpromoted catalyst may be due to the formation of amorphous carbon, which tends to quickly block active sites and reduce the catalytic activity.

Enhancement of the Corrosion Properties of Al-10%Si-2%Cu Alloys with La Addition.

Al-10%Si-2%Cu alloys have been widely used in high-value industries (e.g., aerospace and automobiles) because of their lower specific gravity; however, galvanic corrosion rendered these alloys to have poor corrosion resistance. Therefore, the microstructure and corrosion properties of Al-10%Si-2%Cu alloys were investigated with respect to the lanthanum (La) content. All Al alloy samples were synthesized using gravity casting, with added La contents of 0.00, 0.25, 0.50, 0.75, and 1.00 wt%, and were characterized using microstructural characteristics analysis and electrochemical tests. Adding 0.5 wt% La (xLa-0.5) indicated the finest structure, which had a 4% lower α-Al area fraction than the La-free alloy (xLa-0). However, the area fraction of a 1 wt% La-added (xLa-1) alloy was 2.4% higher than that of xLa-0. The corrosion current density (Icorr) of the xLa-0.5 was 1.09 μA/cm2, representing a 68% decrease as compared to that of xLa-0, and xLa-0.5 reached the highest polarization resistance value (7.32 × 103 Ω·cm2). The improvement in corrosion resistance of xLa-0.5 was due to the rapid and dense formation of a passivation layer induced by its fine structure, as well as the precipitated phase by enhancing the dispersibility of Cu.

Modificated microstructure and enhanced mechanical properties of Cu-Sn-P alloy with rare earth La addition

Rare earths are often added to copper alloys as trace alloying elements to modify the structure and improve related properties. In this study, the Cu-7.8Sn-0.16 P and Cu-7.8Sn-0.16 P-0.15La alloy strips were fabricated through full-chain process of vacuum casting, cold rolling, intermediate annealing, cold rolling and low temperature annealing process. Then, the distinctive microstructure features and mechanical properties of Cu-7.8Sn-0.16 P and Cu-7.8Sn-0.16 P-0.15La alloys were comprehensively analyzed in special view of rare earth affected phase types and property evolution. The results indicate that the addition 0.15 wt% La has effectively refined the dendrite segregation and dispersed the microporosity. Specifically, La combines with P and form a stable and dispersed micron sized LaP2 intermetallic compound, which replaces the low melting point (α+δ+Cu3P) ternary phase in the La-free alloy. Furthermore, a new nanoscale La(Cu2P)2 precipitated phase is characterized in the Cu-7.8Sn-0.16 P-0.15La alloy during low-temperature annealing process. As well, the tensile strength of Cu-7.8Sn-0.16 P-0.15La strips display notable increase to 915 MPa from 834 MPa of Cu-7.8Sn-0.16 P after low-temperature annealing. Such increase in tensile strength is attributed to the formation of La-containing phase of varied sizes in the Cu-7.8Sn-0.16 P-0.15La alloy, where the nano scale La(Cu2P)2 precipitated phase makes the most significant contribution.

Effect of the simultaneous addition of lanthanum and nickel on the oxidation behavior and related area-specific resistance of ferritic stainless steels for solid oxide fuel cell interconnects

The effects of simultaneous lanthanum and nickel addition on the oxidation behavior and area-specific resistance (ASR) of stainless steels for fuelcell interconnects were investigated. The La and Ni addition promoted the entire growth of the oxide layer and increased the roughness of the metal/oxide interface. Despite the thicker oxide scale, these alloys prevented the increase of ASR compared to the alloy with only Ni added. The void analysis indicated that simultaneous La and Ni addition could prevent void growth, leading to lower ASR. The above findings can be interpreted in terms of the fast La diffusion and convoluted metal/oxide interface.

Promotion of toluene catalytic oxidation by M−La/CoOx catalysts directly prepared from Co-MOFs precursors

Volatile organic compounds (VOCs) are identified as volatility and toxicity, and have become major pollutants in the atmosphere. The development of low-energy and high-efficiency environmentally friendly VOCs purification technologies is urgent. Therefore, in this paper, a series of M−La/CoOx (M = La addition) catalysts with different La additions were synthesized by a combination of impregnation and calcination using Co-MOFs as precursors. It was shown that the catalytic activity of the constructed 0.012-La/CoOx catalyst was unexpectedly improved (T90% = 227 °C) under optimal reaction conditions (catalyst mass-air velocity = 60000 mL/(g•h)), initial toluene concentration = 1000 ppm) when employing gaseous toluene (C7H8) as typical target VOCs. Among the La-doping catalysts, the catalysts containing La on the surface have smaller grain sizes as well as more homogeneous grain distributions than the pure Co3O4-MOF catalysts. 0.012-La/CoOx displayed the highest activity, which is attributed to its smaller particle size, larger specific surface area (SSA), richer content of Co3+ and surface Oads, which could enhance the oxygen mobility and the redox performance. The possible degradation mechanism of toluene on 0.012-La/CoOx was revealed using in-situ DRIFTS. This work might provide guidance for the development of efficient and environmentally friendly catalytic oxidation of toluene.

Raman Imaging-A Valuable Tool for Tracking Fatty Acid Metabolism-Normal and Cancer Human Colon Single-Cell Study.

Altered metabolism of lipids is a key factor in many diseases including cancer. Therefore, investigations into the impact of unsaturated and saturated fatty acids (FAs) on human body homeostasis are crucial for understanding the development of lifestyle diseases. In this paper, we focus on the impact of palmitic (PA), linoleic (LA), and eicosapentaenoic (EPA) acids on human colon normal (CCD-18 Co) and cancer (Caco-2) single cells using Raman imaging and spectroscopy. The label-free nature of Raman imaging allowed us to evaluate FAs dynamics without modifying endogenous cellular metabolism. Thanks to the ability of Raman imaging to visualize single-cell substructures, we have analyzed the changes in chemical composition of endoplasmic reticulum (ER), mitochondria, lipid droplets (LDs), and nucleus upon FA supplementation. Analysis of Raman band intensity ratios typical for lipids, proteins, and nucleic acids (I1656/I1444, I1444/I1256, I1444/I750, I1304/I1256) proved that, using Raman mapping, we can observe the metabolic pathways of FAs in ER, which is responsible for the uptake of exogenous FAs, de novo synthesis, elongation, and desaturation of FAs, in mitochondria responsible for energy production via FA oxidation, in LDs specialized in cellular fat storage, and in the nucleus, where FAs are transported via fatty-acid-binding proteins, biomarkers of human colon cancerogenesis. Analysis for membranes showed that the uptake of FAs effectively changed the chemical composition of this organelle, and the strongest effect was noticed for LA. The spectroscopy studies have been completed using XTT tests, which showed that the addition of LA or EPA for Caco-2 cells decreases their viability with a stronger effect observed for LA and the opposite effect observed for PA. For normal cells, CCD-18 Co supplementation using LA or EPA stimulated cells for growing, while PA had the opposite impact.

The influence of La and Ce additions on the solidification of alloys from the Al–Fe system

AbstractAluminium alloys are popular in modern applications due to their lightweight, high strength and ductility. Alloys in the 8xxx series have similar properties to those in the 1xxx series, but are stronger, are more malleable and have higher stiffness. The addition of rare earths (RE) can refine the as-cast microstructure and, as a result, can increase the corrosion resistance and mechanical properties of aluminium alloys at room and high temperatures. The effects of rare earth (Ce and/or La) additions to Al-1.4Fe alloys were investigated. Thermal analysis of the solidification behaviour of the reference alloy showed the occurrence of three reactions corresponding to the formation of α-Al, eutectic (α-Al + AlxFey) and Fe intermetallics, respectively. The results showed similar reactions for the Ce- and/or La-modified alloy, but at slightly different temperatures, indicating a change in the forming phases due to the addition of Ce and/or La. In all cases, the microstructures were typically hypoeutectic, consisting of the primary α-Al and the eutectic (α-Al + AlxFey). The effect of grain refinement of the primary α-Al grains of the as-cast alloy was observed by the addition of RE, while La showed the strongest effect. The effect of the RE additions showed no obvious differences in the morphology of the eutectic AlxFey, although they were present in these phases. When Ce and/or La were added, (α-Al + Al11Ce3) and/or (α-Al + Al11La3) eutectics were formed, while Fe was not detected in these eutectics.

Potential of (La-)NiCu catalysts for the hydrodeoxygenation of 4-(2-furanyl)-3-buten-2-one into fuels: Investigation of support and La addition

Aiming at the valorization of furfural-derived compounds, the potential of (La-)NiCu catalysts for the hydrodeoxygenation of 4-(2-furanyl)-3-buten-2-one has been assessed. The impact of support acidity and the effects of modifying the support with La have been explored. While catalysts with non-acidic supports solely lead to hydrogenation, the acid sites enable furanic ring opening. Additionally, changing the support alters the metal-support interaction strength, with stronger interactions reducing the NiCu alloy particle size and increasing activity. Furthermore, according to Density of States calculations, La further enhances the hydrodeoxygenation activity by increasing the adsorption strength. Also, for the acidic supports, it increases the relative abundance of NiCu alloy on the support surface, further increasing the specific activity. The La-NiCu-Al catalyst demonstrated was the best performing catalyst at 200 °C and 40 bar H2, achieving a high conversion rate of 77 mol kgcat−1 h−1 with a combined selectivity of 29 % towards octane and BTHF at 99 % conversion, and stability over 5 hours Time-On-Stream. Additionally, isopropyl alcohol proved to be an excellent hydrogen donor, as the external H2 pressure does not substantially impact the catalyst activity and selectivity, but H2 itself proved to be important for the catalyst stability.

Inhibition of precipitation structure transformation and enhancement of hardness by trace La addition in Cu-1Cr-0.1Zr alloy sheets

Cu-1Cr-0.1Zr and Cu-1Cr-0.1Zr-0.07La alloy sheets were prepared by the following process: vacuum casting– homogenization treatment– hot forging– solid solution treatment– cold rolling– aging treatment. The effect of trace La on the aging behavior and mechanical properties of Cu-1Cr-0.1Zr alloy was investigated. Compared to the Cu-1Cr-0.1Zr (0La) alloy, the Cu-1Cr-0.1Zr-0.07La (0.07La) alloy exhibited a significant increase in hardness and a slight decrease in electrical conductivity due to larger number of finer and coherent f.c.c Cr-rich precipitates. It was found that trace La can affects the evolution of precipitation phases. The thermodynamics calculation indicates that with La addition, the Cr-rich precipitates were much more inclined to nucleate with f.c.c structure, and the precipitation growth kinetics results indicate that the addition of La can reduce the activation energy of precipitation, promote the precipitation of f.c.c Cr phase and form Cr-poor zones, making it more difficult to form bcc nuclei. Thus, the transformation of nanoscale Cr-rich precipitates from f.c.c structure to bcc structure was inhibited due to trace La addition, causing higher hardness with appropriate conductivity.

High-Pressure Die Casting of Al–Ce–La–Ni–Fe Alloys

The effects on phase equilibria of La and Fe additions to the Al–Ce–Ni-based alloy system are explored under high-pressure die casting conditions. The addition of La to Al–Ce–Ni-based alloy system only reacts with Ce synergistically to promote the formation of the Al11(Ce,La)3 intermetallic phase as predicted by CALculation of PHAse Diagrams (CALPHAD) and verified experimentally. High Fe additions react with Ni to form the Al9FeNi intermetallic phase, which is an additional eutectic former. The targeted co-precipitation type eutectic morphology is achieved in the alloys studied. Additional coarse particles of Al11(Ce,La)3, present in the alloys studied and not predicted by CALPHAD, are attributed to possible inclusions of Ce and La oxide, present in the mischmetal feedstock used. Both alloys exhibit exceptional mechanical stability after 10 hours at 400 °C due to the stability of the phases formed during solidification. The alloy with high Fe additions possessed better mechanical properties after heat treatment based on the higher eutectic content and more substantial improvement to the morphology of secondary phases after treatment.

The effects of Nd, La, and Ca addition on the corrosion properties of as-cast and as-rolled ZM21 Mg alloys

In this study, the effects of Nd, La, and Ca elements added to ZM21 alloy was investigated in terms of parameters such as microscopic, mechanical, and corrosion properties. The content of each of the elemental constituents was 0.5% by weight. The microstructural and mechanical behaviours of the investigated alloys were examined by XRD, EDX, SEM, OM, hardness surveys, tensile tests, and corrosion experiments. According to the XRD results, Ca5Zn3, Ca2Mg6Zn3, LaZn2, LaMg3, Mg41Nd5, and Mg12Nd phases emerged on the investigated alloys. The grain sizes of the alloys were refined by element addition and rolling process, thus increasing their mechanical properties. Ca increased the hardness of the ZM21 alloys, but this had a negative effect on the rolled specimens. The tensile value of ZM21 alloy as cast decreased by 39.702%, 48.080%, 45.678% with the addition of (0.5% La+0.5% Nd), (0.5% La+0.5% Ca), (0.5% La+0.5% Nd+0.5% Ca), respectively. The tensile value of ZM21 alloy with (0.5% La+0.5% Nd) addition increased by 58.302% as rolled. Tensile test could not be performed because the rolled alloys with 0.5% Ca addition were fragmented during rolling. Ca contributed positively to the corrosion behaviour of the casting ZM21 alloy, but it worsened it in the rolled alloys. White oxide areas on the surface of the rolled alloys indicated an increased degree of corrosion formation.

Effect of trace rare earth La on microstructure and properties of Al-7%Si-0.6%Fe alloy

<sec>Al-Si alloys have been widely used in electronic information, communication, and other fields because of their high specific strength, excellent castability and good thermal conductivity. In recent years, with the rapid development of 5G communication technology, electronic communication equipment is gradually developing towards high integration and lightweight. The power of related equipment is higher and higher, which puts forward higher requirements for thermal conductivity and mechanical properties of materials.</sec><sec>Si can improve the fluidity and strength of the Al-Si alloy, but a large amount of Si will aggravate the lattice distortion and increases amount of eutectic Si. This will reduce the plasticity of the alloy, increase the electron scattering and reduce the thermal conductivity. In order to improve the mechanical properties and thermal conductivity of Al-Si alloys, chemical inoculation is generally used. Sr is usually used as modifier and Al-B serves as grain refiner. However, the simultaneous addition of Sr and B into Al-Si alloy results in “poisoning” phenomenon, it becomes impossible to refine <i>α</i>-Al grains and modify eutectic Si simultaneously.</sec><sec>In recent years, rare earth La has attracted more and more attention in improving the properties of aluminum alloys. However, previous studies mainly focused on the effects of La addition, consequently, the research on the effects of combined addition of La, Sr, B on the microstructure and properties of Al-7%Si-0.6%Fe alloy is lacking. In this work, solidification experiments are performed to investigate the effects of combined addition of La, Sr, B on the microstructure and properties of Al-7%Si-0.6%Fe alloy. The results show that the addition of trace rare earth La can effectively eliminate the poisoning effect of Sr and B, and enhance the modification effect of eutectic Si. Besides, the addition of La can promote the formation of <i>α</i>-Al heterogeneous nucleation substrate LaB<sub>6</sub> and La can be used as a surfactant to reduce the undercooling of <i>α</i>-Al nucleation, thus it refines <i>α</i>-Al grains. The thermal conductivity of the alloy is significantly improved when the addition of La ranges from 0.02% to 0.06%; with the further increase of La addition, LaAlSi intermetallic compounds are formed in the alloy, leading the thermal conductivity of the alloy to decrease.</sec>