In situ Study of Internal Load Transfer in a Novel Metal/Ceramic Composite Exhibiting Lamellar Microstructure Using Energy Dispersive Synchrotron X-ray Diffraction
In situ Study of Internal Load Transfer in a Novel Metal/Ceramic Composite Exhibiting Lamellar Microstructure Using Energy Dispersive Synchrotron X-ray Diffraction
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DOI：
10.1002/adem.200800352
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发表时间：
2009-06-01
影响因子：
3.6
通讯作者：
Wanner, Alexander
中科院分区：
文献类型：
--
作者：
Roy, Siddhartha;Gibmeier, Jens;Wanner, Alexander
金属基复合材料（MMC）因其高比刚度和强度、高耐磨性和耐疲劳性以及增强的高温性能而在技术上具有吸引力。[1]最近，通过陶瓷悬浮液冷冻铸造加工的陶瓷预成型件的出现，开启了制造具有互穿结构的金属/陶瓷复合材料的新可能性。有关冷冻铸造工艺的详细信息，请参阅参考文献[2, 3] 通过冷冻水基悬浮液（浆料）生产的陶瓷预制件具有典型的分层层状域结构。这些区域的尺寸和内部结构由冷冻铸造参数控制。[2, 4] 这种方式生产的预成型件具有优异的液体和气体渗透性以及可接受的机械强度，适合通过液态金属渗透制造金属/陶瓷复合材料。[2]通过这种方式，可以制造陶瓷含量在技术上重要的中间范围（约 30-70 vol%）的复合材料。 MMC 的承载能力由内部载荷从柔软且柔顺的金属部件转移到坚硬且刚性的增强材料来控制。[5]基于衍射的技术最适合复合材料内部载荷传递的原位研究，因为它们提供相选择信息。 [6]例如，此类测量已成功在颗粒增强、[7] 晶须增强、[6] 和短纤维增强 [8, 9] MMC 中进行。这些实验通常涉及使用中子衍射（单色 [8, 9] 或飞行时间测量 [6]）或角色散同步加速器 X 射线衍射。 [7]能量色散高能同步加速器 X 射线衍射提供了通量和穿透深度的独特组合，因此允许在相当小的规格体积下进行批量应力分析。[10]根据布拉格定律，衍射线的能量与对应的 {hkl} 型平面的间距有关，如下：
Metal matrix composites (MMC) are technically attractive because of their high specific stiffness and strength, high wear and fatigue resistance, and enhanced high temperature properties.[1] A new possibility of fabricating metal/ceramic composites having an interpenetrating structure has recently been opened by the availability of ceramic preforms processed by freeze-casting of ceramic suspensions. Details about the freeze casting process can be found in ref.[2, 3] Ceramic preforms produced by freezing of water-based suspensions (slurries) have a typical hierarchical lamellar domain structure. The size and internal structure of these domains are controlled by the freeze casting parameters.[2, 4] Preforms produced this way have excellent permeability for liquids and gases along with acceptable mechanical strengths and they are suitable for the fabrication of metal/ceramic composites by infiltration of liquid metal.[2] This way, it is possible to fabricate composites with ceramic contents in the technologically important intermediate range of about 30–70 vol%. The load bearing capacity of MMCs is controlled by the internal load transfer from the soft and compliant metallic component to the hard and stiff reinforcement.[5] Diffraction-based techniques are most suitable for the in situ study of internal load transfer in composites because they provide phase selective information.[6] Such measurements have eg, successfully been carried out in particle reinforced,[7] whisker reinforced,[6] and short fiber reinforced [8, 9] MMCs. These experiments typically involved the use of either neutron diffraction (monochromatic [8, 9] or time of flight measurements [6]) or angle dispersive synchrotron X-ray diffraction.[7] Energy dispersive high-energy synchrotron X-ray diffraction offers a unique combination of flux and penetration depth and thus allows stress analysis in the bulk with fairly small gauge volumes.[10] According to Bragg’s law, the energy of the diffraction lines is related to the spacing of the corresponding planes of type {hkl} according to