Abrasive wear of Si3N4MoSi2 composites
Abrasive wear of Si3N4MoSi2 composites
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DOI：
10.1016/s0043-1648(96)07380-2
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发表时间：
1997-03
期刊：
影响因子：
5
通讯作者：
J. Hawk;D. Alman;J. Petrovic
中科院分区：
文献类型：
--
作者：
J. Hawk;D. Alman;J. Petrovic
将二硅化钼(MoSi2)颗粒添加到氮化硅(Si3N4)中，形成陶瓷基-金属间化合物复合材料。在Si3N4中添加MoSi2的好处包括更高的强度、更高的断裂韧性、不会损失抗氧化性和更低的电阻率。然而，由于MoSi2的硬度约为Si3N4的一半，Si3N4MoSi2复合材料的比磨损率预计将因MoSi2的加入而显著降低。然而，在本研究中发现，在碳化硅颗粒的两体磨损过程中，添加小体积分数(≤20%)的MoSi2颗粒对Si3N4的耐磨性影响不大或略有提高。在较高的体积分数下，Si3N4MoSi2复合材料的磨损速率不超过单块Si3N4的1.5倍。复合材料的体积磨损量取决于复合材料的硬度、断裂韧性和显微组织特征(即MoSi2颗粒尺寸)。在相同体积分数下，当复合材料对具有相同的硬度和断裂韧性时，MoSi2颗粒越小的复合材料磨损率越低。Si3N4--MoSi2复合材料的磨粒磨损行为可以用复合材料的混合物逆规律来描述。
Molybdenum disilicide (MoSi2) particles have been added to silicon nitride (Si3N4) to form ceramic matrix-intermetallic composites. Benefits associated with the addition of the MoSi2to Si3N4include higher strength, higher fracture toughness, no loss in oxidation resistance, and lower electrical resistivity. However, since the hardness of MoSi2is approximately half that of Si3N4, a significant decrease in the specific wear rate of the Si3N4MoSi2composites is expected to result from the incorporation of the MoSi2in the Si3N4. In this study, it was found, however, that the wear resistance of Si3N4improves slightly or is unaffected by additions of small volume fractions (≤20%) of MoSi2particles, during two-body abrasion by SiC particles. At higher volume fractions, the Si3N4MoSi2composites wear at rates no greater than 1.5 times that of monolithic Si3N4. The volume wear of the composites was dependent on composite hardness, fracture toughness and microstructural features (i.e. MoSi2particle size). Given equivalent hardness and fracture toughness for a composite pair at the same volume fraction, however, the composite with the smaller MoSi2particle exhibited the lower wear rate. The abrasive wear behavior of the Si3N4MoSi2composites can be described in terms of the inverse rule of mixtures for composites.