Synthesis and Sintering最新文献_第7页

Microstructure and mechanical properties of Ti3SiC2 MAX phases sintered by hot pressing 热压烧结Ti3SiC2 MAX相的组织与力学性能

Synthesis and Sintering Pub Date : 2021-12-27 DOI: 10.53063/synsint.2021.1472

Sheida Haji Amiri, Nasser Pourmohammadie Vafa

{"title":"Microstructure and mechanical properties of Ti3SiC2 MAX phases sintered by hot pressing","authors":"Sheida Haji Amiri, Nasser Pourmohammadie Vafa","doi":"10.53063/synsint.2021.1472","DOIUrl":"https://doi.org/10.53063/synsint.2021.1472","url":null,"abstract":"The Ti3SiC2 used in this project has been purchased ready-made. This study aimed to investigate the effect of sintering temperature on samples' microstructure and mechanical properties, including three-point flexural strength, Vickers hardness, and fracture toughness. Therefore, Ti3SiC2 samples were sintered under a vacuum atmosphere at a pressure of 35 MPa for 30 minutes at two temperatures of 1500 °C and 1550 °C by hot pressing. The microstructure obtained from the fracture cross-section of the samples shows that by increasing the sintering temperature to 1550 °C, the microstructure of this sample becomes larger than the sintered sample at 1500 °C. Also, increasing the sintering temperature to 1550 °C causes the decomposition of Ti3SiC2 to TiC, which can be seen in the X-ray diffraction pattern (XRD). In addition, the relative density of the sintered sample at 1550 °C is 98.08% which is higher than that of the sintered sample at 1500 °C with the result of 89%. On the other hand, the three-point flexural strength (227.5 MPa), the Vickers hardness (~9 GPa), and the fracture toughness (8.6 MPa.m1/2) of the sintered sample at 1500 °C are higher due to the fine-grained structure.","PeriodicalId":22113,"journal":{"name":"Synthesis and Sintering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75649172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Role of Ti3AlC2 MAX phase on characteristics of in-situ synthesized TiAl intermetallics. Part II: Phase evolution Ti3AlC2 MAX相对原位合成TiAl金属间化合物性能的影响第二部分:阶段演化

Synthesis and Sintering Pub Date : 2021-12-26 DOI: 10.53063/synsint.2021.1453

M. Akhlaghi, E. Salahi, S. A. Tayebifard, G. Schmidt

{"title":"Role of Ti3AlC2 MAX phase on characteristics of in-situ synthesized TiAl intermetallics. Part II: Phase evolution","authors":"M. Akhlaghi, E. Salahi, S. A. Tayebifard, G. Schmidt","doi":"10.53063/synsint.2021.1453","DOIUrl":"https://doi.org/10.53063/synsint.2021.1453","url":null,"abstract":"In this research, the 2nd part of a series of papers on the processing and characterization of TiAl–Ti3AlC2 composites, the phase evolution during the manufacturing process was investigated by X-ray diffraction (XRD) analysis and Rietveld refinement method. Metallic Ti and Al powders with different amounts of previously-synthesized Ti3AlC2 additives (10, 15, 20, 25 and 30 wt%) were ball-milled and densified by spark plasma sintering (SPS) under 40 MPa for 7 min at 900 °C. Before the sintering process, XRD test verified that the powder mixtures contained metallic Ti and Al as well as Ti3AlC2 and TiC (lateral phase synthesized with Ti3AlC2) phases. In the sintered composites, the in-situ synthesis of TiAl and Ti3Al intermetallics as well as the presence of Ti3AlC2 and the formation and Ti2AlC MAX phases were disclosed. The weight percentage of each phase in the final composition of the samples and the crystallite size of different phases were calculated by the Rietveld refinement method based on the XRD patterns. The size of Ti3AlC2 crystallites in sintered samples was compared with the crystallite size of synthesized Ti3AlC2 powder.","PeriodicalId":22113,"journal":{"name":"Synthesis and Sintering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77439881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Sintering behavior and microwave dielectric properties of CaTi1-x(Nb1/2Al1/2)xO3 CaTi1-x(Nb1/2Al1/2)xO3的烧结行为和微波介电性能

Synthesis and Sintering Pub Date : 2021-11-09 DOI: 10.53063/synsint.2021.1467

Akbar Khan, Asif Ali, I. Khan

引用次数: 3

Thermodynamically study of phase formation of Ni-Ti-Si nanocomposites produced by self-propagating high-temperature synthesis method 自蔓延高温合成法制备Ni-Ti-Si纳米复合材料相形成的热力学研究

Synthesis and Sintering Pub Date : 2021-11-08 DOI: 10.53063/synsint.2021.1443

H. Aghajani, Arvin Taghizadeh Tabrizi, Salva Arabpour Javadi, Mohammad Ehsan Taghizadeh Tabrizi, Aytak Homayouni, S. Behrangi

引用次数: 3

Sintered transparent polycrystalline ceramics: the next generation of fillers for clarity enhancement in corundum 烧结透明多晶陶瓷:提高刚玉透明度的新一代填料

Synthesis and Sintering Pub Date : 2021-09-29 DOI: 10.53063/synsint.2021.1342

Mubashir Mansoor, Mehya Mansoor, M. Mansoor, Ted Themelis, Filiz Çinar Şahin

{"title":"Sintered transparent polycrystalline ceramics: the next generation of fillers for clarity enhancement in corundum","authors":"Mubashir Mansoor, Mehya Mansoor, M. Mansoor, Ted Themelis, Filiz Çinar Şahin","doi":"10.53063/synsint.2021.1342","DOIUrl":"https://doi.org/10.53063/synsint.2021.1342","url":null,"abstract":"A significant proportion of mined natural corundum (ruby and sapphire) contain fractures, which negatively affects a gemstone’s clarity and value. Over the past decades, heat treatment techniques have been developed for either fracture healing, or filling to make such gems marketable. The clarity enhancement processes are mainly based on techniques which are either not durable, as in the case of lead silicate fillers, or do not yield perfect transmittance through a fracture, as in the case of borax based fluxes. Therefore, the gemstone treatment community is actively in pursuit of better techniques for clarity enhancement in corundum. Given that application of pressure is a recent advancement in the heat treatment processes of natural sapphire, it is essential to explore the possibilities regarding different outcomes such treatments can have. In this perspective paper, we have briefly described how application of pressure during heat treatments can lead to in-situ sintering of transparent polycrystalline ceramics within the fractures of corundum, which can result in clarity enhancement. Spinel-structure based fillers can be tailored to mimic corundum in terms of tribological, chemical and optical properties. Therefore, gemstones treated with such fillers will be durable, unlike currently used glass-based filler material. We also provide a possible explanation for ghost-fissures in sapphires heated under pressure, as being a by-product of in-situ sintering process of ceramic fillers that are thermodynamically compatible with Al2O3. The prospect of transparent polycrystalline ceramics in the gem and jewelry industry opens a new field of research in this area, given that ceramic fillers can outperform currently used methods and material for clarity enhancement in gemstones. In essence, we present a novel application for sintered transparent polycrystalline ceramics.","PeriodicalId":22113,"journal":{"name":"Synthesis and Sintering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90237590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Tribological behavior and mechanical properties of friction stir processed HDPE/Fe-Fe3O4 composites 搅拌摩擦加工HDPE/Fe-Fe3O4复合材料的摩擦学行为和力学性能

Synthesis and Sintering Pub Date : 2021-09-28 DOI: 10.53063/synsint.2021.1350

Saeed Karimi, S. M. Arab, S. Zeidabadi, S. Javadpour

引用次数: 2

Role of Ti3AlC2 MAX phase on characteristics of in-situ synthesized TiAl intermetallics. Part I: sintering and densification Ti3AlC2 MAX相对原位合成TiAl金属间化合物性能的影响第一部分:烧结和致密化

Synthesis and Sintering Pub Date : 2021-09-26 DOI: 10.53063/synsint.2021.1347

M. Akhlaghi, E. Salahi, S. A. Tayebifard, G. Schmidt

引用次数: 3

Advances in metal-based vanadate compound photocatalysts: synthesis, properties and applications 金属基钒酸盐复合光催化剂的合成、性能及应用研究进展

Synthesis and Sintering Pub Date : 2021-09-24 DOI: 10.53063/synsint.2021.1344

Asieh Akhoondi, Usisipho Feleni, B. Bethi, A. Idris, A. Hojjati-Najafabadi

{"title":"Advances in metal-based vanadate compound photocatalysts: synthesis, properties and applications","authors":"Asieh Akhoondi, Usisipho Feleni, B. Bethi, A. Idris, A. Hojjati-Najafabadi","doi":"10.53063/synsint.2021.1344","DOIUrl":"https://doi.org/10.53063/synsint.2021.1344","url":null,"abstract":"Among the ongoing research on photocatalysis under visible-light, it has been shown that doped or hybrid catalysts are more active than a single catalyst alone. However, problems including visible light absorption, a low quantity of energetic sites on surfaces, and rapid recombination of the photo-electron hole pair produced by light have prohibited photocatalysts from being used in a practical and widespread manner. To overcome these problems, synthesis of nanostructure hybrid catalyst using several methods has attracted much attention. Several procedures have been suggested for the preparation of photocatalysts with the desired structure and morphology. Preparation methods similar to partial modification may lead to diverse structures and qualities. In this regard, the development of efficient, low-cost photocatalysts and rapid synthesis is the most important issues that should be considered. This review discusses various methods and mechanisms that work with the modification of vanadium compounds as photocatalysts to progress their photocatalytic efficiency. In addition, the effects of synthesis temperature, solution pH and concentration on the photocatalytic performance are also described in detail.","PeriodicalId":22113,"journal":{"name":"Synthesis and Sintering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79710976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 37

Experimental investigation and parameter optimization of Cr2O3 atmospheric plasma spray nanocoatings Cr2O3大气等离子喷涂纳米涂层的实验研究及参数优化

Synthesis and Sintering Pub Date : 2021-09-19 DOI: 10.53063/synsint.2021.1339

S. Hashemi, N. Parvin, Z. Valefi, S. Parvizi

引用次数: 3

Ab-initio study of paramagnetic defects in Mn and Cr doped transparent polycrystalline Al2O3 ceramics Mn和Cr掺杂透明多晶Al2O3陶瓷顺磁缺陷的Ab-initio研究

Synthesis and Sintering Pub Date : 2021-09-13 DOI: 10.53063/synsint.2021.1340

Mubashir Mansoor, Mehya Mansoor, M. Mansoor, Zuhal Er, Filiz Çinar Şahin

{"title":"Ab-initio study of paramagnetic defects in Mn and Cr doped transparent polycrystalline Al2O3 ceramics","authors":"Mubashir Mansoor, Mehya Mansoor, M. Mansoor, Zuhal Er, Filiz Çinar Şahin","doi":"10.53063/synsint.2021.1340","DOIUrl":"https://doi.org/10.53063/synsint.2021.1340","url":null,"abstract":"Birefringence is a major source of difficulty in sintering of transparent polycrystalline alumina ceramics, especially as the grain size exceeds a few hundred nanometers, which ultimately leads to complete opacity, mainly due to scattering of light. Recent studies have made it clear that by application of a strong magnetic field, alumina grains can be aligned along a particular crystallographic orientation, which minimizes scattering due to birefringence, and enhances transparency. Defects that cause spin delocalization are known to induce a paramagnetic behavior in alumina ceramics. Therefore, such defects have become a focal point of research for magnetic field assisted sintering of transparent polycrystalline alumina, in order to reduce the necessary magnetic field strength during production process. In light of recent studies on paramagnetic potentials of transition metal doped alumina, we have applied Spin Polarized Density Functional Theory (SP-DFT) calculations on manganese and chromium doped and co-doped alumina to calculate the magnetic moments, density of states and defect formation energies, which should be expected from this system of dopants, along with their interactions with oxygen vacancies. The results clearly indicate that formation of a point defect comprised of chromium and manganese positioned substitutionally at adjacent aluminum sites, in vicinity of an oxygen vacancy can induce a magnetic moment equivalent to 5 Bohr magnetons (μβ), outperforming previously reported defects. Based on this study we find it likely that chromium and manganese co-doping in alumina can further reduce the required magnetic field strength for production of transparent polycrystalline alumina.","PeriodicalId":22113,"journal":{"name":"Synthesis and Sintering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84608220","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6