I.Z. Al-Yahmadi, A. Gismelseed, H.M. Widatallah, F. Bzour, F. Al Ma'Mari, A. Al-Rawas, M. ElZain
{"title":"Enhancement of the magnetocaloric effect in Nd0.6-xGdxSr0.4MnO3 (0.02 ≤ x ≤ 0.1) perovskite manganites: The role of Gd3+ ionic substitution","authors":"I.Z. Al-Yahmadi, A. Gismelseed, H.M. Widatallah, F. Bzour, F. Al Ma'Mari, A. Al-Rawas, M. ElZain","doi":"10.1016/j.matchemphys.2024.130109","DOIUrl":"10.1016/j.matchemphys.2024.130109","url":null,"abstract":"<div><div>The influence of Gd<sup>3+</sup> doping on the magnetocaloric properties of Nd<sub>0.6-<em>x</em></sub>Gd<sub><em>x</em></sub>Sr<sub>0.4</sub>MnO<sub>3</sub> (0.02 ≤ <em>x</em> ≤ 0.1) compounds, prepared using auto-combustion sol-gel technique, has been studied. Rietveld refinement of the X-ray diffraction (XRD) data has shown all compounds to be nanocrystalline with single-phased orthorhombic structures that index to the <em>Pnma</em> space group. The unit cell volumes reduce as the Gd<sup>3+</sup> ions gradually substitute the Nd<sup>3+</sup>ones. The tuning Mn<sup>4+</sup>/Mn<sup>3+</sup> ratio for all compounds, which are slightly lower than that of the Gd-free compound, demonstrates almost equal amounts of both ions. A ferromagnetic-to-paramagnetic transition is observed with rising temperature wherein the Curie temperature (T<sub>C</sub>) gradually drops with increasing Gd<sup>3+</sup> concentration (<em>x</em>). All materials exhibit ferromagnetism at 2 K, with saturation magnetization values that increase slightly with <em>x</em>. Both the calculated maximum magnetic entropies (<span><math><mrow><mo>|</mo><mrow><mo>Δ</mo><msubsup><mi>S</mi><mi>M</mi><mi>Max</mi></msubsup></mrow><mo>|</mo></mrow></math></span>) and relative cooling powers (RCP) increase to relatively large values with increasing temperature and <em>x</em> values. The values obtained for <span><math><mrow><mo>|</mo><mrow><mo>Δ</mo><msubsup><mi>S</mi><mi>M</mi><mi>Max</mi></msubsup></mrow><mo>|</mo></mrow></math></span> and RCP for Nd<sub>0.6-<em>x</em></sub>Gd<sub><em>x</em></sub>Sr<sub>0.4</sub>MnO<sub>3</sub> (0.02 ≤ <em>x</em> ≤ 0.1) are comparable with those of standard pure Gd revealing their potential as magnetic refrigeration systems.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"329 ","pages":"Article 130109"},"PeriodicalIF":4.3,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fujia Ben , Dan Xu , Xinyuan Zhou , Taolin Yu , Jiale Wei , Wenjie Zhao
{"title":"Crystalline structure and dielectric relaxor behavior of MnO2-modified 0.8BaTiO3-0.2BiScO3 ceramics for energy storage application","authors":"Fujia Ben , Dan Xu , Xinyuan Zhou , Taolin Yu , Jiale Wei , Wenjie Zhao","doi":"10.1016/j.matchemphys.2024.130119","DOIUrl":"10.1016/j.matchemphys.2024.130119","url":null,"abstract":"<div><div>Based on the synergistic roles of defect dipoles and MnO<sub>2</sub> sintering aid, 0.8BaTiO<sub>3</sub>-0.2BiScO<sub>3</sub> (BTBS<sub>0.2</sub>) ceramics with and without 0.3 wt% MnO<sub>2</sub> were prepared by a solid-phase reaction route. The impacts of MnO<sub>2</sub> dopant and sintering conditions on the crystalline structure, micro-morphology, dielectric, and energy storage properties were investigated in detail. The X-ray diffraction (XRD) and Raman results demonstrate the coexistence of tetragonal (T) and pseudo-cubic (pC) phases. The increased pC phase content caused by MnO<sub>2</sub> modification is beneficial for the improvement of the relaxation degree. The O 1s fine spectra of X-ray photoelectron spectroscopy (XPS) confirms a remarkable increase in the concentration of oxygen vacancy due to the acceptor Mn dopant, indicating the valence changes of Mn ions from Mn<sup>4+</sup> to Mn<sup>3+</sup>/Mn<sup>2+</sup>. The reduced dielectric loss is induced by the improved density and the pinning effect from the defect dipoles, thereby yielding a higher <em>E</em><sub>b</sub>. An optimal energy density of <em>W</em><sub>rec</sub> = 0.70 J/cm<sup>3</sup> with a high energy efficiency of <em>η</em> = 95.8 % at 140 kV/cm was realized in the BTBS<sub>0.2</sub>+Mn ceramic composition sintered at 1300 °C. Moreover, the ceramic also exhibits good temperature stability (30–120 °C). Therefore, the BTBS<sub>0.2</sub>+Mn ceramics have a promising application prospect in the energy storage field.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"329 ","pages":"Article 130119"},"PeriodicalIF":4.3,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142571471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Improvement in the performance of indium free dye sensitized solar cell by the use of polyaniline composite","authors":"Neha Patni, Shibu G. Pillai","doi":"10.1016/j.matchemphys.2024.130108","DOIUrl":"10.1016/j.matchemphys.2024.130108","url":null,"abstract":"<div><div>The photovoltaic study of the fabricated dye sensitized solar cells is revealed in this paper. To provide indium free approach, fluorine doped tin oxide (FTO) and aluminium doped zinc oxide (AZO) glass substrate were used as charge collectors for counter electrodes and photoanode respectively. Also, a novel and natural mixed dye was used as sensitizer and mixture of doped polymer (polyaniline with metallic oxides of tin, vanadium and cerium) and iodide-triiodide couple was utilized as electrolyte for the cell. Optical band gap and light absorption performance of dyes were studied by ultraviolet–visible (UV–vis) spectroscopy. Surface morphology and elemental composition of polymer composites was studied using scanning electron microscopic (SEM) with energy dispersive X ray (EDX) analysis. Phase analysis of the composites was determined by X-ray diffraction and thermal behavior with the help of thermogravimetric analysis (TGA). Photovoltaic characteristics (I–V) and induced photon to current efficiency (IPCE) measurements were also investigated. Highest IPCE of 17.7 % was observed when polyaniline was doped with oxide of vanadium. Hence an efficient, green, indium free and novel cell is fabricated by the usage of different charge collector substrate, natural dye sensitizer and quasi solid-state electrolyte.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"329 ","pages":"Article 130108"},"PeriodicalIF":4.3,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiangfen Li , Yelong Tong , Zhongyi Yin , Hui Jia , Xi Yan , Xiaoyue Guo , Shiwen Lei , Long Gao , Jinxing Liu , Zechao Tao , Zhanjun Liu
{"title":"Revealing synergistic relationship of thermal conduction and electromagnetic shielding of reduced graphene oxide film","authors":"Xiangfen Li , Yelong Tong , Zhongyi Yin , Hui Jia , Xi Yan , Xiaoyue Guo , Shiwen Lei , Long Gao , Jinxing Liu , Zechao Tao , Zhanjun Liu","doi":"10.1016/j.matchemphys.2024.130092","DOIUrl":"10.1016/j.matchemphys.2024.130092","url":null,"abstract":"<div><div>The present work tries to explore the evolution process of electro-magnetic interference shielding effectiveness and thermal conductivity of graphene film. There is an obvious promotion of electrical conductivity (from 3.51 × 10<sup>−3</sup> to 769.20 S m<sup>−1</sup>) when GO is thermally reduced at 1100 °C. Correspondingly, the reduced graphene oxide (rGO) achieves the highest EMI shielding effectiveness (∼54.84 dB) at 1100 °C which is a synergetic result of electrical conductivity and porous structure with rich defects. The rGO is furtherly graphitized at 2800 °C (G-rGO) to repair the defects and C–C network and then mechanically rolled to a densified film with bulk density of 1.64 g cm<sup>−3</sup> (called as DG-rGO). The thermal conductivity of DG-rGO membrane increases to 720.56 W m<sup>−1</sup> K<sup>−1</sup> after graphitization and rolling. Porous structure and defects are beneficial to higher EMI shielding effectiveness while dense structure without defects lead to higher thermal conductivity. Therefore, the highest EMI shielding effectiveness and thermal conductivity cannot be obtained simultaneously. A reference range is provided to fulfill the request of EMI shielding and thermal conductivity.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"329 ","pages":"Article 130092"},"PeriodicalIF":4.3,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Omar R. Soliman , Ahmed F. Mabied , Saber A. Ibrahim , Ahmad M. Labeeb
{"title":"Nanosilica/recycled polycarbonate composites for electronic packaging","authors":"Omar R. Soliman , Ahmed F. Mabied , Saber A. Ibrahim , Ahmad M. Labeeb","doi":"10.1016/j.matchemphys.2024.130105","DOIUrl":"10.1016/j.matchemphys.2024.130105","url":null,"abstract":"<div><div>Several simple methods were performed to recycle compact discs (CDs) using an alkaline solution. The hydrophilic silica nanoparticles were incorporated into the recycled deinked polycarbonate CDs, and these particles affected the dielectric, structure, and thermal properties of the recycled polycarbonates. The thermal properties of recycled CDs were studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). No significant change in the thermal stability of polycarbonate/silica nanocomposites was observed with the mechanical/chemical modifications. X-ray diffraction (XRD) revealed the structural aspects, showing a correlation between crystallinity, silica nanoparticles, and modification methods. The mechanically treated sample after chemical handling had the lowest degree of crystallinity (48 %), showing that the modification methods enhanced the formation of the amorphous state, thus affecting its dielectric properties. Scanning electron microscopy (SEM) characterized the CD samples' microstructure and morphology. Finally, the dielectric properties were studied using broadband dielectric spectroscopy (BDS) in the 10<sup>1</sup>–10<sup>6</sup> Hz range. The samples prepared using chemical and mechanical treatments were of low dielectric loss. This increases its importance when such samples are used as antistatic charge materials. For these reasons, recycled PC/SiO<sub>2</sub> nanocomposites are recommended as effective packaging materials for electronic components.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"329 ","pages":"Article 130105"},"PeriodicalIF":4.3,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fatma Chergui , Adel Mokhtar , Soumia Abdelkrim , Amina Sardi , Mohammed Hachemaoui , Bouhadjar Boukoussa , Amal Djelad , Mohammed Sassi , Gianluca Viscusi , Mohamed Abboud
{"title":"Optimizing catalytic performance: Reduction of organic dyes using synthesized Fe3O4@AC magnetic nano-catalyst","authors":"Fatma Chergui , Adel Mokhtar , Soumia Abdelkrim , Amina Sardi , Mohammed Hachemaoui , Bouhadjar Boukoussa , Amal Djelad , Mohammed Sassi , Gianluca Viscusi , Mohamed Abboud","doi":"10.1016/j.matchemphys.2024.130094","DOIUrl":"10.1016/j.matchemphys.2024.130094","url":null,"abstract":"<div><div>This article presents a sustainable method for the catalytic reduction of both simple and binary dye systems using magnetic activated carbon (Fe<sub>3</sub>O<sub>4</sub>@AC) synthesized from almond shells, an agricultural waste biomass. The reduction of methylene blue (MB) and Congo red (CR) was investigated in the presence of NaBH<sub>4</sub>, and a series of physical-chemical experiments were conducted to elucidate the mechanism of dye conversion and its performance. The results confirmed the successful synthesis of Fe<sub>3</sub>O<sub>4</sub> nanoparticles on the activated carbon surface. The calculated rate constants in a simple system were 0.34 min⁻<sup>1</sup> for MB and 0.25 min⁻<sup>1</sup> for CR, in the binary system, the Fe<sub>3</sub>O<sub>4</sub>@AC catalyst demonstrated enhanced selectivity for the cationic MB dye, attributable to the robust, attractive surface charge. The study aimed to enhance catalytic performance by employing optimization curves generated from a three-level Box-Behnken Design (BBD) simulation. Experimental results indicated that the optimal catalyst dose, dye concentration, and reaction duration were 4–7 mg, 80–120 mg/L, and 5–20 min, respectively. Response surface methodology (RSM) was developed by processing the findings from 17 replicated experiments using a two-quadratic polynomial model, establishing a functional link between the experimental parameters and MB conversion. Optimal conditions for MB conversion were determined to be 7 mg of catalyst, 80 mg/L of MB concentration, and a reaction time of 12.5 minutes, resulting in an estimated conversion rate of 99.99 %. This prediction was validated by experimental findings, with regression analysis confirming a high correlation (R<sup>2</sup> > 0.99) between the predicted and observed values. Additionally, the Fe<sub>3</sub>O<sub>4</sub>@AC catalyst demonstrated good recyclability and stable performance over three consecutive cycles, maintaining high conversion efficiency without loss of performance. These findings demonstrate that Fe<sub>3</sub>O<sub>4</sub>@AC is a viable approach for the rapid and efficient remediation of dyes in water.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"329 ","pages":"Article 130094"},"PeriodicalIF":4.3,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D.T. Yu , R. Wang , C.L. Wu , Z.Z. Wang , S. Zhang , C.H. Zhang , H.T. Chen , X.P. Tao
{"title":"Effects of laser energy density on the resistance to wear and cavitation erosion of FeCrNiMnAl high entropy alloy coatings by laser cladding","authors":"D.T. Yu , R. Wang , C.L. Wu , Z.Z. Wang , S. Zhang , C.H. Zhang , H.T. Chen , X.P. Tao","doi":"10.1016/j.matchemphys.2024.130122","DOIUrl":"10.1016/j.matchemphys.2024.130122","url":null,"abstract":"<div><div>FeCrNiMnAl high entropy alloy (HEA) coatings are prepared on the surface of 304 stainless steel (304 SS) by laser cladding. The effects of laser energy density on the residual stress, microstructure, nanoindentation behavior, the resistance to wear, corrosion and cavitation erosion (CE) of FeCrNiMnAl HEA coatings are studied. Experimental results shows that when the laser energy density decreases from 40 J/mm<sup>2</sup> to 24 J/mm<sup>2</sup>, the phase composition of the FeCrNiMnAl HEA coatings remains unchanged with a single BCC solid solution and the elements are uniformly distributed without obvious segregation. The average grain size of the HEA coatings is refined from 73.5 to 41.7 μm. When the laser energy density is 28 J/mm<sup>2</sup> for S3 sample, the coating displays good forming quality and excellent comprehensive performance. The specific wear rate is only 8.2 % that of the 304 SS substrate. In addition, S3 exhibits the highest corrosion resistance as indicated by the highest corrosion potential (<em>E</em><sub><em>corr</em></sub>) and the lowest corrosion current density (<em>I</em><sub><em>corr</em></sub>) in 3.5 wt% NaCl solution. After 10-h CE, the mean depth erosion rate (MDER) of S3 is the lowest (1.69 ± 0.03 μm/h), which is much lower than that of 304 SS (4.96 ± 0.13 μm/h), and the pure mechanical damage plays a dominant role in CE, followed by the synergistic damage effect. The excellent CE resistance of S3 is attributed to its excellent combination of corrosion resistance, mechanical properties and the self-recovery ability of passivation film.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"329 ","pages":"Article 130122"},"PeriodicalIF":4.3,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142586226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M.A. Hussein , A. Madhan Kumar , M.A. Azeem , N. Ankah , S. Saravanan
{"title":"Development of Ti-Zr-Nb-Ta-Ag high entropy alloy for dental implants: In vitro corrosion behavior, antibacterial effect, and surface characteristics","authors":"M.A. Hussein , A. Madhan Kumar , M.A. Azeem , N. Ankah , S. Saravanan","doi":"10.1016/j.matchemphys.2024.130114","DOIUrl":"10.1016/j.matchemphys.2024.130114","url":null,"abstract":"<div><div>This study presents a new biological high-entropy alloy (Bio-HEA) composed of 35Ti-35Zr-20Nb-5Ta-5Ag (at. %) for potential dental implant applications. The Bio-HEA underwent processing for various durations of mechanical alloying, followed by compaction and sintering. The processed Bio-HEA was tested for corrosion resistance in an artificial saliva medium, antibacterial properties, and surface characteristics. Surface topography and wettability were investigated using atomic force microscopy, surface profilometry, and contact angle measurements. Mechanical alloying, X-ray diffraction, and scanning electron microscopy revealed the formation of a solid-solution Bio-HEA with body-centered cubic crystal structures, with phase variations depending on the processing conditions. The Bio-HEA exhibited significantly higher microhardness values (4.38 GPa and 5.35 GPa) than commercial pure titanium (CPTi) and Ti-6Al-4V alloy, respectively. An increased ball-milling time resulted in higher microhardness for Bio-HEA and enhanced in vitro corrosion resistance in artificial saliva compared to CPTi. This was evidenced by a significant nobler shift of approximately 200 mV in the corrosion potential, with a prominent decrease of approximately two orders of magnitude in the corrosion current density and a higher charge transfer resistance. Additionally, the Bio-HEA demonstrated a lower contact angle compared to that of the Ti-6Al-4V alloy and CPTi. The Bio-HEA achieved antibacterial efficiencies of 91.76 % and 93.0 % compared to Ti-6Al-4V alloy and CPTi, respectively. The enhanced microhardness, antibacterial properties, in vitro corrosion resistance in artificial saliva, and wettability of Bio-HEA compared to commercial Ti-6Al-4V alloy and CPTi makes it a promising candidate for dental bioimplant applications.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"329 ","pages":"Article 130114"},"PeriodicalIF":4.3,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142594105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"CO2 reforming of methane over Ni-Al-LDH catalysts prepared with different precipitants","authors":"Isabele Giordani Wenzel, Oscar W. Perez-Lopez","doi":"10.1016/j.matchemphys.2024.130115","DOIUrl":"10.1016/j.matchemphys.2024.130115","url":null,"abstract":"<div><div>NiAl-LDH catalysts were synthesized using the co-precipitation method with different precipitant. One of the samples (NiAl_C) was prepared with a Na<sub>2</sub>CO<sub>3</sub> solution, while the other sample (NiAl_M) was prepared with a mixture of Na<sub>2</sub>CO<sub>3</sub> and NaOH. These catalysts were evaluated in the dry reforming of biogas, utilizing a synthetic biogas consisting of 60 % (v/v) CH<sub>4</sub> and 40 % CO<sub>2</sub>. Characterization techniques including X-ray diffractometry (XRD), N<sub>2</sub> adsorption-desorption, thermogravimetric analysis (TGA), and temperature-programmed reduction and oxidation (H<sub>2</sub>-TPR and TPO, respectively), NH<sub>3</sub>, CO<sub>2</sub>, and H<sub>2</sub> desorption (NH<sub>3</sub>-TPD, CO<sub>2</sub>-TPD, and H<sub>2</sub>-TPD, respectively) where used in different stages of catalysts. Both samples resulted in LDH with small differences in cell parameter c and specific surface area. The precipitant containing NaOH led to an increase in the NiAl<sub>2</sub>O<sub>4</sub> spinel phase and in the metallic dispersion of NiAl_M, enhancing thermal stability and resistance to sintering. However, this elevated metallic area facilitated the presence of acid sites, promoting CH<sub>4</sub> decomposition and carbon deposition. The reduction step proved unnecessary for this catalyst, as the reduced catalyst led to an increase in structured carbon formation. The delicate balance between thermal stability and carbon deposition favors the NiAl_M sample under reaction conditions without the reduction step.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"329 ","pages":"Article 130115"},"PeriodicalIF":4.3,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142571555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zichen Zhang , Hao Yang , Ruilei Gong , Miaomiao Chen , Zengjie Li , Hailin Lu
{"title":"Optimization of the performance of copper/graphite system for GIL Tri‐post grounding electrode based on plasma sintering technology","authors":"Zichen Zhang , Hao Yang , Ruilei Gong , Miaomiao Chen , Zengjie Li , Hailin Lu","doi":"10.1016/j.matchemphys.2024.130117","DOIUrl":"10.1016/j.matchemphys.2024.130117","url":null,"abstract":"<div><div>Grounding electrodes, as crucial components of GIL bushings, experience friction with the GIL shell during long-term operation, generating metal particles that induce partial discharge. This phenomenon can lead to internal insulation breakdown, severely compromising GIL operation. This study focuses on enhancing the wear resistance of grounding electrodes by proposing a solution involving copper-graphite composites. Copper/graphite composite materials were fabricated using Spark Plasma Sintering technology. Additionally, the impact of graphite content and particle size on wear resistance, hardness, and electrical conductivity was comprehensively analyzed. Performance evaluation using radar chart analysis identified the optimal solution. The results indicate that at a sintering temperature of 960 °C, pressure of 45 MPa, and holding time of 15 min, with a graphite mass fraction of 7 %, the grounding electrode material exhibits a smooth surface and uniform distribution of graphite. Furthermore, when the graphite particle size is 4 μm, the friction coefficient remains approximately 0.7 with minimal fluctuations. The abrasion produces scratches measuring only 190 μm, and the wear rate is recorded at 2.1128 × 10<sup>−4</sup> mm³/N·m, while the hardness reaches 59.6 HV, an increase of 19.6 HV compared to a particle size of 40 μm. In conclusion, an appropriate graphite content effectively enhances the wear resistance of the grounding electrode, and a reduction in graphite particle size optimizes overall performance. When the composite material contains 7 % graphite with a particle size of 4 μm, the performance is optimal, allowing the grounding electrode to maintain its original properties while demonstrating excellent wear resistance. This study provides a significant approach to optimizing the performance of grounding electrodes.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"329 ","pages":"Article 130117"},"PeriodicalIF":4.3,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}