Effect of Iron Silicon Addition in the Sintering Behavior of Silicon Nitride

To compare the influence of Al2O3 and TiO2 on the sintering behavior of partial reaction bonding silicon nitride (RBSN) and post densification behavior, different amounts of Al2O3 or TiO2 have been added into Si-Si3N4-Y2O3 system. The results indicated that a high amount of Al2O3 addition inhibited the reaction bonding process, a lower nitridation degree was obtained, while TiO2 has limited influence on nitridation, only slightly decreased nitration degree with increasing TiO2 addition. After post sintered at 1800 °C, a density ranging from 2.31 to 3.09g/cm3 were obtained with additions of Al2O3 and TiO2, much larger than the one without them. The linear shrinkage of post-sintered samples was strongly promoted with high Al2O3 content, but it was irrelevant with the amount of TiO2. The highest bending strength of 523MPa can be obtained with addition of 6wt% Al2O3. TiO2 transformed into TiN which located at grain boundary interfaces, restraining the grain growth of β-Si3N4 and leading to an inferior flexural strength after post sintered at 1800 °C.

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Synthesis and Characterization of Nickel-Iron-Silicon Nitride Nanocomposite

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.97-101.1360 ◽

2010 ◽

Vol 97-101 ◽

pp. 1360-1363 ◽

Cited By ~ 11

Author(s):

Yusrini Marita ◽

Iskandar Idris Yaacob

Keyword(s):

Thin Films ◽

Silicon Nitride ◽

Crystallite Size ◽

Iron Film ◽

Face Centered Cubic ◽

Mapping Procedure ◽

Nickel Iron ◽

Iron Silicon ◽

Nanocomposite Thin Films ◽

Face Centered

Nickel-iron-silicon nitride nanocomposite thin films were prepared by electrodeposition technique. The deposition was performed at current density of 11.5 A dm-2. Nano-size silicon nitride was mixed in the electrolyte bath as dispersed phase. The effects of silicon nitride nanoparticulates in the nickel-iron nanocomposite thin films were investigated in relation to the amount of silicon nitride in the plating bath. X-ray diffraction (XRD) analysis showed that the deposited nickel iron film has face-centered cubic structure (FCC). However, a mixture of body-centered cubic (BCC) and face-centered cubic (FCC) phases were observed for nickel iron-silicon nitride nanocomposite films. The crystallite size of Ni-Fe nanocomposite coating decreased with increasing amount of silicon nitride in the film. From elemental mapping procedure, Si3N4 nanopaticles were uniformly distributed in the Ni-Fe film. The presence of silicon nitride increased the hardness of the film. The microhardness of the nickel-iron nanocomposite increased from 495 HV for nickel-iron film to 846 HV for nickel-iron nanocomposite film with 2 at. % Si. The coercivity of Ni-Fe nanaocomposite films increases with decreasing crystallite size.

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