Sintering behaviour of silicon nitride powders produced by carbothermal reduction and nitridation

Karakuş, Nuray; Kurt, Ali Osman; Duran, Cihangir; Öztürk, Cem; Toplan, H. Özkan

doi:10.1016/j.apt.2012.12.004

Cited by 12 publications

(7 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As we know, the slags can be reused as a secondary resource depending intensively on its unique physico-chemical characteristics. In our previous study on the basic characterization of coal gasification slag, it was found that the slag mainly nicontains SiO 2 , Al 2 O 3 , CaO and C, which could be used to synthesize Ca-α-SiAlON by carbothermal reduction nitridation (CRN) method [15], which is a simple and low-cost method to compound nitride powders [16,17]. More importantly, the nitrogen source for CRN of coal gasification slag could be self-provided by air separation unit in IGCC system.…”

Section: Introductionmentioning

confidence: 99%

Influence of High-Temperature Liquid on Phase Composition and Morphology of Carbothermal Reduction-Nitridation Products from Coal Gasification Slag

et al. 2020

View full text Add to dashboard Cite

In this paper, the products using three kinds of coal gasification slags as starting materials were obtained via carbothermal reduction-nitridation at 1450 °C. The effects of high-temperature liquid on the phase composition and morphology of the samples were investigated by XRD and SEM, while the content of high-temperature liquid was calculated by the computer software package FactSage. The results show that: (1) the existence of high-temperature liquid phase is beneficial to the formation and growth of Ca-α-SiAlON phase; (2) The formation of long-columnar Ca-α-SiAlON were greatly affected by the content and viscosity of liquid phase, which is in non-linear relationship with aspect ratios of Ca-α-SiAlON. Among the three kinds of slags, the HT slag with relatively high liquid phase content and the lowest viscosity is the most favorable to the growth of elongated Ca-α-SiAlON grain; the aspect ratio of the formed Ca-α-SiAlON is the largest; Compared to the SH slag with the highest liquid phase content and viscosity, Ca-α-SiAlON prepared from TE slag possesses the smallest aspect ratio, which exhibits equiaxed grain morphology.

show abstract

Section: Introductionmentioning

confidence: 99%

Influence of High-Temperature Liquid on Phase Composition and Morphology of Carbothermal Reduction-Nitridation Products from Coal Gasification Slag

et al. 2020

View full text Add to dashboard Cite

show abstract

“…The most prevalent methods for preparing Si 3 N 4 powders include direct nitridation method, carbothermal reduction-nitridation (CRN) method and thermal decomposition method [5,6,7]. By CRN method, Si 3 N 4 powders or columnar grains with excellent size distribution and physical properties could be synthesized and used as thermal conductive fillers or commercial applications for manufacturing engineering devices [8,9]. For example, Karakus et al [9].…”

Section: Introductionmentioning

confidence: 99%

“…By CRN method, Si 3 N 4 powders or columnar grains with excellent size distribution and physical properties could be synthesized and used as thermal conductive fillers or commercial applications for manufacturing engineering devices [8,9]. For example, Karakus et al [9]. synthesized α-Si 3 N 4 powders by CRN of synthetic silica and activated charcoal at 1470 °C, and then used the obtained α-Si 3 N 4 powders as the raw materials to prepare the Si 3 N 4 ceramic by a pressureless sintering method.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

β-Si3N4 Microcrystals Prepared by Carbothermal Reduction-Nitridation of Quartz

et al. 2019

View full text Add to dashboard Cite

Single phase β-Si3N4 with microcrystals was synthesized via carbothermal reduction-nitridation (CRN) of quartz and carbon coke powder as starting materials. The effects of reaction parameters, i.e., heating temperature, holding time, C/SiO2 ratio, Fe2O3 additive and β-Si3N4 seeds on the phase transformation and morphology of products were investigated and discussed. Rather than receiving a mixture of both α- and β- phases of Si3N4 in the products, we synthesized powders of β-Si3N4 single polymorph in this work. The mechanism for the CRN synthesis of β-Si3N4 from quartz and the formation mechanism of Fe3Si droplets were discussed. We also firstly reported the formation of Fe3Si Archimedean solids from a CRN process where Fe2O3 was introduced as additive. Comparing to the gear-like short columnar morphology observed in samples without β-Si3N4 seeding, the addition of β-Si3N4 seeds led to an elongated morphology of final products and much finer widths. In addition, the β-Si3N4 microcrystals exhibited a violet‒blue spectral emission range, which could be highly valuable for their future potential optoelectronic applications.

show abstract

“…Figure 1 shows the crystal structure of silicon nitride, where silicon atoms (black) and nitrogen (green) form hexagonal crystal structures [8]. In this study, silicon direct nitridation method was employed to fabricate Si3N4 ceramic material by placing Si powder under the gasses mixture of argon and nitrogen or ammonia [9][10][11][12][13][14][15][16][17][18][19][20]. The effect of the reaction conditions are assessed and optimized.…”

Section: Introductionmentioning

confidence: 99%