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Fabrication of Metal/Ceramic In situ Composites by Directed Oxidation of Aluminum Melt

铝熔体定向氧化制备金属/陶瓷原位复合材料

基本信息

批准号：
03555154
负责人：
KAGAWA Yutaka
金额：
$ 4.16万
依托单位：
University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research (B)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1993
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-03555154/
关键词：
Directed Oxidation Aluminum Melt Al_2O_3 Al alloy Composites In situ Processing Microstructure of Composite Growth Mechanism Optimum Processing Variables Directed Nitridation 溶融アルミニウム合金 in situプロセス生成モデルシミュレーション熱的特性力学的特性 A

项目摘要

Directed melt oxidation is an attractive process for fabrication of dense, near net shaped metal/ceramic composite materials. An experimental and theoretical study was conducted to study the growth mechanism of the Al_2O_3/Al alloy composites. The oxidation of Al-Mg-Si alloys was carried out at temperatures ranging from 900 to 1700K under dry air gar atmosphere. The optimum processing variables were obtained experimentally and microstructure of the obtained composite was compared with the processing condition. The typical composite structure was three-dimensionally interconnected Al_2O_3 phase (70 vol%) and residual aluminum alloy phase (30 vol%). The growth process was divided into three characteristic stages. Stage I corresponded to formation of porous spinel layr above the liquid aluminum alloy. After stage I, bulk Al_2O_3/Al alloy composite formed and the growth rate showed the maximum value. During stage III, the oxidation rate constantly decreased. The decreased oxidation rates were due to increased melt viscosity, higher diffusion distances from aluminum and depletion of aluminum alloy reservoir. The modeling and analysis have been done on the growth process and the result reasonably agrees with the experimental result. The application of this process to Al_2O_3/Al alloy matrix reinforced with SiC fiber or SiC particle was also carried out.

直接熔融氧化是一种制备致密、近终形金属/陶瓷复合材料的有吸引力的方法。对Al_2O_3/Al合金复合材料的生长机理进行了实验和理论研究。在900 ~ 1700 K的温度范围内，在干燥的空气气氛中对Al-Mg-Si合金进行了氧化。通过实验确定了最佳工艺参数，并对复合材料的显微组织进行了比较。复合材料的典型结构为三维互联的Al_2O_3相（70体积%）和残余的铝合金相（30体积%）。生长过程分为三个特征阶段。阶段I对应于在液态铝合金上方形成多孔尖晶石层。第一阶段后，形成块体Al_2O_3/Al合金复合材料，生长速率达到最大值。在第三阶段，氧化速率不断下降。氧化速率的降低是由于熔体粘度的增加、铝的扩散距离的增大以及铝合金储层的耗尽。对生长过程进行了模拟和分析，模拟结果与实验结果吻合较好。并将该工艺应用于SiC纤维或SiC颗粒增强Al_2O_3/Al合金基体。