JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2019
·Vol. 103
·期 1
·122-135
·
IF 3.094
Jingkun Xu,Zunlan Hu,Yao Han,Di An,Zhipeng Xie
In the present work, high-quality MgSiN 2 powders were prepared by a combustion synthesis method, based on Mg-Si 3 N 4 -N 2 system. The effects of additive content (NH 4 Cl or NH 4 F) and N 2 pressure on phase composition and crystal morphology of products were investigated. The results suggested that both NH 4 Cl and NH 4 F additives alleviated agglomeration and decreased the grain size of MgSiN 2 . In addition, NH 4 Cl did not result in the formation of an extra impurity, while MgF 2 residue was found when NH 4 F was introduced. Therefore, NH 4 Cl additive was considered as a better choice for the preparation of MgSiN 2 powders in comparison with NH 4 F additive. According to the observation of some MgSiN 2 whiskers and notably increased Si content under low N 2 pressure, the pressure of N 2 over 0.5 MPa was essential to have a complete reaction in the present work. Finally, MgSiN 2 -Si 3 N 4 composite powders with quasi-spherical morphology were prepared by adding excessive Si 3 N 4 and NH 4 Cl additive in reactant. The formation and growth mechanism of MgSiN 2 grains was reasonably speculated based on the experimental results. Because of the remarkable merits, the as-prepared Si 3 N 4 -MgSiN 2 composite powders showed great potential for alternative sintering aid in the sintering of Si 3 N 4 -based ceramics.
研究领域:
材料科学
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陶瓷
·
合成方法
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Applied Ceramic Technology
·
2022
·Vol. 20
·期 3
·1855-1864
·
IF 2.328
Shi Fu,Zengchao Yang,Honghua Li,Liang Wang,Yong Li,Jiangtao Li
Si 3 N 4 ceramics were prepared by gas pressure sintering at 1900°C for 12 h under a nitrogen pressure of 1 MPa using Gd 2 O 3 and MgSiN 2 as sintering additives. The effects of the Gd 2 O 3 /MgSiN 2 ratio on the densification, microstructure, mechanical properties, and thermal conductivity of Si 3 N 4 ceramics were systematically investigated. It was found that a low Gd 2 O 3 /MgSiN 2 ratio facilitated the thermal diffusivity of Si 3 N 4 ceramics while a high Gd 2 O 3 /MgSiN 2 ratio benefited the densification and mechanical properties. When the Gd 2 O 3 /MgSiN 2 ratio was 1:1, Si 3 N 4 ceramics obtained an obvious exaggerated bimodal microstructure and the optimal properties. The thermal conductivity, flexural strength, and fracture toughness were 124 W·m −1 ·k −1 , 648 MPa, and 9.12 MPa·m 1/2 , respectively. Comparing with the results in the literature, it was shown that Gd 2 O 3 -MgSiN 2 was an effective additives system for obtaining Si 3 N 4 ceramics with high thermal conductivity and superior mechanical properties.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Miao Zhou,Yun Liu,Xiaolei Li,Tianyi Sui,Dong Su,Huiming Ji
Silicon nitride (Si 3 N 4 ) ceramics were prepared by gas-pressure sintering using Y 2 O 3 –MgSiN 2 as a sintering additive. The densification behavior, phase transition, and microstructure evolution were investigated in detail, and the relevance between the microstructure and the performance (including thermal conductivity and mechanical properties) was further discussed. A significant change from a bimodal to a homogeneous microstructure and a decreased grain size occurred with increasing Y 2 O 3 –MgSiN 2 content. When the small quantity of preformed β-Si 3 N 4 nuclei grew preferentially and rapidly in a short time, an obvious bimodal microstructure was obtained in the sample with 4 mol% and 6 mol% Y 2 O 3 –MgSiN 2 . When more β-Si 3 N 4 nuclei grew at a relatively rapid rate, the sample with 8 mol% Y 2 O 3 –MgSiN 2 showed a microstructure consisting of numerous abnormally grown β-Si 3 N 4 grains and small grains. When more β-Si 3 N 4 nuclei grew simultaneously and slowly, there was a homogeneous microstructure and smaller grains in the sample containing 10 mol% Y 2 O 3 –MgSiN 2 . Benefitting from the completely dense, significant bimodal microstructure, low grain boundary phase, and excellent Si 3 N 4 –Si 3 N 4 contiguity, the sample containing 6 mol% Y 2 O 3 –MgSiN 2 exhibited great comprehensive performance, with a maximum thermal conductivity and fracture toughness of 84.1 W/(m⋅K) and 8.97 MPa m 1/2 , as well as a flexural strength of 880.2 MPa.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Yun Liu,Ruixiang Liu,Yuanhang Zheng,Jixue Zhao,Tianyi Sui,Xiaolei Li,Bin Lin
To investigate the mechanism of the influence of the sintering additive ratio on the microstructure evolution of silicon nitride (Si 3 N 4 ) ceramics, Si 3 N 4 ceramics were prepared by gas pressure sintering using different ratios of Y 2 O 3 /MgSiN 2 as additives. Varying the ratio of Y 2 O 3 /MgSiN 2 changed the composition of the liquid phase, thereby affecting the densification process and phase transformation rate of Si 3 N 4 ceramics, and ultimately changing their microstructure. The reduction in the Y 2 O 3 /MgSiN 2 ratio raised the N/O and Si/O ratios in the system, which increased the liquid phase viscosity. The Si 3 N 4 grain distribution varied from "normal to bimodal". In the case of increasing the proportion of MgSiN 2 and prolonging the sintering time, more of the glass phase evaporated, which reduced the content of the low thermal conductivity phase and increased the continuity of Si 3 N 4 /Si 3 N 4 . Therefore, Si 3 N 4 ceramics with 1 wt% Y 2 O 3 and 5 wt% MgSiN 2 exhibited excellent properties after sintering at 1900 °C for 12 h, with thermal conductivity, bending strength , and fracture toughness of 106.7 Wm −1 K −1 , 776 MPa, and 11.66 MPa m 1/2 , respectively.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Rencong Geng,Tingye Fan,Ping Yang,Wenlei Jia,Ju Zhou,Mingwei Li,Wenhan Qi,Shiqi Li,Jiao Han,Yiming Zeng
Si 3 N 4 ceramics are highly valued for their exceptional thermal conductivity and mechanical properties. This study investigated the effects of different addition ratios of Y 2 O 3 -MgO-MgSiN 2 ternary sintering additives on liquid phase viscosity, densification, microstructure, thermal conductivity and mechanical properties. The incorporation of MgSiN 2 as sintering additives introduced additional Si and N into the liquid phase, forming a nitrogen-rich liquid phase that promoted the grain growth showing a bimodal distribution. When the MgO/MgSiN 2 ratio reached 2/3, the moderate liquid phase viscosity facilitated enhanced densification and grain growth. This resulted in an increased number of large grains, a moderate grain size distribution, and a good bimodal microstructure. Consequently, the 2M3N exhibited superior properties, including a thermal conductivity of 105.22 W m −1 K −1 , a fracture toughness of 5.91 MPa m 1 / 2 , and a bending strength of 726.12 MPa. The study demonstrates that precise control of the Y 2 O 3 -MgO-MgSiN 2 ratio can effectively regulate the microstructure, leading to improved thermal and mechanical performance.
研究领域:
材料科学
·
陶瓷
·
热性能
·
机械工程
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Applied Ceramic Technology
·
2026
·Vol. 23
·期 3
·e70208
·
IF 2.6
He Ma,Zizheng Cai,Kun Tian,Feng Sun,Lijuan Zhou,Shuang Li
Silicon nitride ceramics are attractive candidates for substrate applications because they combine electrical insulation, mechanical robustness, and the capacity for efficient heat dissipation. Their practical thermal conductivity, however, is often restricted by lattice oxygen defects and grain-boundary phases generated during processing. In the present study, MgSiN 2 was incorporated into a Yb 2 O 3 –MgO additive system to regulate oxygen-related defects and to tailor the liquid-phase sintering behavior of Si 3 N 4 ceramics fabricated by gas-pressure sintering at 1850°C. The effects of MgSiN 2 content on densification, phase evolution, microstructural development, room-temperature thermal conductivity, and mechanical properties were systematically examined. The specimen containing 4 wt.% MgSiN 2 displayed the most balanced overall performance, with a relative density of 96.17%, a flexural strength of 912 MPa, a fracture toughness of 8.1 MPa·m 1/2 , and a Vickers hardness of 13.6 GPa. When the MgSiN 2 level was further increased to 6 wt.%, the room-temperature thermal conductivity rose to 83.1 W·m −1 ·K −1 , although the mechanical properties deteriorated because of reduced densification and microstructural coarsening. These results show that controlled MgSiN 2 addition provides an effective route for adjusting the oxygen state, microstructure, and overall performance of Si 3 N 4 ceramics.
✓ 已验证
DOI
高影响因子
International Journal of Applied Ceramic Technology
·
2025
·Vol. 22
·期 6
·e70052
·
IF 2.3
Na Zhang,Min Niu,Lei Su,De Lu,Kang Peng,Hongjie Wang
Si 3 N 4 ceramics stand out as ideal materials for advanced electronic packaging substrates due to their high mechanical strength, high-temperature resilience, and minimal dielectric constant. Optimizing both the mechanical and thermal conductivity is essential for ensuring their reliable performance. In this study, a systematic investigation into the impact of both oxygen-containing sintering additives (Y 2 O 3 -MgF 2 and Y 2 O 3 -MgSiN 2 ) and oxygen-free sintering additives (YF 3 -MgF 2 and YF 3 -MgSiN 2 ) on the microstructure, flexural strength, and thermal conductivity of Si 3 N 4 ceramics has been performed. It demonstrates that the Si 3 N 4 ceramic sintered with the YF 3 -MgSiN 2 additive achieves a remarkable thermal conductivity of 111.63 W·m −1 ·K −1 and a flexural strength of 774.7 MPa, which is relatively rare among the reported Si 3 N 4 ceramics. These exceptional properties are attributed to the use of YF 3 -MgSiN 2 additive, which leads to a significant reduction in lattice oxygen content, along with a decrease in the liquid phase formation temperature, thereby promoting grain development. Furthermore, the decomposition of MgSiN 2 at high temperatures plays a key role in purifying the grain boundaries. This study provides a promising approach for developing high-performance Si 3 N 4 ceramics with excellent thermal conductivity and mechanical strength.
✓ 已验证
产品关联
DOI
高影响因子
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