Synthesis and characterization of zirconium diboride precursor based on polycentric bridge bonds

Xie, Zhihui; Deng, Xinqing; Suo, Xingwen; Zhou, Ting; Gou, Yanzi

doi:10.1016/j.matchemphys.2015.03.068

Cited by 14 publications

(8 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…22 Some recent advances have surmounted this obstacle by directly synthesizing borides or carbides in a single step. 23 Continuing research challenges in synthesis include synthesizing higher purity UHTC powders, identifying mechanisms and kinetics of synthesis reactions, and designing liquid/polymer precursors that have higher ceramic yields and are less sensitive to degradation under ambient conditions.…”

Section: Continuing Challengesmentioning

confidence: 99%

Ultra-high temperature ceramics: Materials for extreme environments

2017

View full text Add to dashboard Cite

This paper identifies gaps in thepresent state of knowledge and describes emerging research directions for ultra-high temperature ceramics. Borides, carbides, and nitrides of early transition metals such as Zr, Hf, Nb, and Ta have the highest melting points of any known compounds, making them suitable for use in extreme environments.Studies of synthesis, processing, densification, thermal properties, mechanical behavior, and oxidation of ultra-high temperature ceramics have generated a substantial base of knowledge, but left unanswered questions. Emerging research directions include testing/characterization in extreme environments, composites, computational studies, and new materials.

show abstract

Section: Continuing Challengesmentioning

confidence: 99%

Ultra-high temperature ceramics: Materials for extreme environments

2017

View full text Add to dashboard Cite

show abstract

“…In the FT‐IR spectrum of PHPS, typical absorption bands related to Si−H (2159 cm −1 ), [12] N−H (1120, 3302 cm −1 ), [12] and Si−N−Si (840–1050 cm −1 ) [12b] groups are expectedly observed. The absorption bands at 1088 cm −1 and 2260–2534 cm −1 are characteristic vibrations of BMS and are assigned to B−H units [13] . The peaks appearing at 940 and 1246 cm −1 are related to the stretching vibration modes of Hf−N−C in TDMAH [12b] .…”

Section: Resultsmentioning

confidence: 95%

“…The absorption bands at 1088 cm À 1 and 2260-2534 cm À 1 are characteristic vibrations of BMS and are assigned to BÀ H units. [13] The peaks appearing at 940 and 1246 cm À 1 are related to the stretching vibration modes of HfÀ NÀ C in TDMAH. [12b] As can be seen from the spectra of the BHPSX precursors, the intensity of the peaks related to SiÀ H and NÀ H groups becomes smaller with the addition of BMS and TDMAH into PHPS, while the peak intensity of BÀ N (1315 cm À 1 ) gradually increases.…”

Section: Synthesis Of the Single-source Precursorsmentioning

confidence: 99%

Single‐source‐precursor derived bulk Si₃N₄/HfB_xN_1‐x ceramic nanocomposites with excellent oxidation resistance

Tian

et al. 2022

Zeitschrift anorg allge chemie

View full text Add to dashboard Cite

In the present work, bulk Si3N4/HfBxN1‐x ceramic nanocomposites were successfully fabricated via a polymer‐derived ceramic approach. The chemical reaction to form the single‐source precursor was confirmed by FT‐IR and XPS, in which both Si−H and N−H groups of perhydropolysilazane react with borane dimethyl sulfide complex and tetrakis(dimethylamido) hafnium(IV). The investigation of the polymer‐to‐ceramic transformation of the synthesized precursors indicates that Hf‐ and B‐modified PHPS exhibits high ceramic yields of up to 100 wt % after pyrolysis at 1000 °C under ammonia. Moreover, XRD and TEM results show that the SiHfBN ceramics with a molar ratio of B : Hf=5 and 10 resist crystallization at temperatures up to 1500 °C and separate after annealing at 1700 °C into nanocomposites comprising of an α‐Si3N4 matrix with embedded ternary HfBxN1‐x phases, solid solutions of rock salt‐type HfN and HfB. Based on the investigation, warm‐pressing was applied to fabricate bulk SiHfBN specimens, and the oxidation behavior of samples annealed at 1700 °C was recorded at 1500 °C over a range of oxidation times between 1 and 50 h. The weight changes of Si3N4/HfBxN1‐x ceramics with B : Hf molar ratios of 2 : 1, 5 : 1 and 10 : 1 are 4.31 %, 4.37 % and 2.57 %, respectively. The formation of HfSiO4, B2O3 and SiO2 during oxidation plays a crucial role for the improvement of the oxidation resistance of the Si3N4/HfBxN1‐x ceramics.

show abstract

“…The processing method and process conditions all play a role and the required control needs to be identified and learnt. Precursor infiltration and pyrolysis (PIP) [195], [196]and slurry impregnation process (SIP) [255], [256] are green-forming procedures used to produce continuous fibre-reinforced ceramic composites. Hot pressing & spark plasma sintering can reduce the processing times and enable high densities to be achieved.…”

Section: Discussionmentioning

confidence: 99%

Selection, processing, properties and applications of ultra-high temperature ceramic matrix composites, UHTCMCs – a review

Binner

Porter

Baker

et al. 2020

International Materials Reviews

251

View full text Add to dashboard Cite

April 1 st 2019 he was also the Deputy Head of the College of Engineering & Physical Sciences. He has been active in ceramics processing research since 1981 and has published ~220 refereed papers, as well as editing or contributing to 19 books and holding 7 patents with an 8 th recently submitted. He has attracted 129 research grants to date, totalling ~£16.5M, this includes a current portfolio of about £1.9M. The focus of his research is the generation of both the necessary scientific understanding and the required engineering solutions for the design and development of materials and process routes that display technical and/or economic advantages over existing approaches. The range of products worked on ranges from nanostructured to traditional ceramics, interpenetrating composites to ultra-high temperature ceramic matrix composites. He has worked closely with industry to translate key developments, e.g. through the creation of a spin-out company to develop a ceramic sensor for measuring soil matric potential (1991), or via licensing, e.g. manufacturing routes for producing engineering ceramic foams (1995) and nanostructured ceramics (2012). He has supervised 35 Ph.D. students and 2 M.Phil. students to successful completion and 38 postdoctoral researchers. A further 7 Ph.D. students and 6 postdoctoral researchers are currently being supervised with more positions currently advertised. His research has received both national and international recognition; he has given ~65 keynotes, plenary and invited talks at international conferences, whilst the Institute of Materials, Minerals and Mining has awarded him the Holliday Prize (1995), Ivor Jenkins Medal

show abstract

Synthesis and characterization of zirconium diboride precursor based on polycentric bridge bonds

Cited by 14 publications

References 30 publications

Ultra-high temperature ceramics: Materials for extreme environments

Ultra-high temperature ceramics: Materials for extreme environments

Single‐source‐precursor derived bulk Si₃N₄/HfB_xN_1‐x ceramic nanocomposites with excellent oxidation resistance

Selection, processing, properties and applications of ultra-high temperature ceramic matrix composites, UHTCMCs – a review

Contact Info

Product

Resources

About

Synthesis and characterization of zirconium diboride precursor based on polycentric bridge bonds

Cited by 14 publications

References 30 publications

Ultra-high temperature ceramics: Materials for extreme environments

Ultra-high temperature ceramics: Materials for extreme environments

Single‐source‐precursor derived bulk Si3N4/HfBxN1‐x ceramic nanocomposites with excellent oxidation resistance

Selection, processing, properties and applications of ultra-high temperature ceramic matrix composites, UHTCMCs – a review

Contact Info

Product

Resources

About

Single‐source‐precursor derived bulk Si₃N₄/HfB_xN_1‐x ceramic nanocomposites with excellent oxidation resistance