Design, Fabrication and Characterization of Advanced Metal Matrix Composites with Bimodal Size Distributions of Ceramic Particulates

具有陶瓷颗粒双峰尺寸分布的先进金属基复合材料的设计、制造和表征

基本信息

批准号：
13450285
负责人：
WAKASHIMA Kenji
金额：
$ 9.54万
依托单位：
Tokyo Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2003
项目状态：
已结题

项目摘要

This research has been done in an attempt to develop a new type of aluminum-base metal matrix composites (MMCs) with particulate ceramic reinforcements as advanced high-temperature structural materials. Paying special attention to different roles of ceramic particles with much different sizes in conventional particulate-reinforced MMCs and dispersion-strengthened alloys, we have planed to examine, toward the design of novel 'hybrid' particulate MMCs, the effects of particle size on elevated-temperature stiffness and creep resistance in MMCs which contain either one or both of fine (<1μm) and coarse (【approximately equal】10μm) ceramic particles. To this end, the present work begins with reactive synthesis of TiB_2 /Al MMCs from Al-Ti-B mixed elemental powders because this reactive powder processing can produce submicron-size TiB_2 particulates in situ in aluminum matrices. Here, we are much involved in a problem as to the undesirable compound Al_3Ti that forms intermediately and often r … More emains in final products under the usual processing conditions with heating temperatures of up to 1000℃. Our detailed study has shown that two intermediate compounds AlB_2 and Al_3Ti, known previously, can decompose in the presence of molten aluminun, forming TiB_2 and Al, i.e. AlB_2 +Al_3Ti→ TiB_2+4Al. This reveals a proper range of reactant compositions, xAl-Ti-2B with x【greater than or equal】4 for making the desired TiB_2 /Al two-phase MMCs, the critical composition x=4 corresponding to a maximum of 27.9 vol.% TiB_2. Then, the work proceeds to the fabrication of three different 20 vol.% TiB_2/Al MMCs wherein the particulate reinforcement is either one of very fine (<1μm) in situ and coarse (【approximately equal】10μm) 'ex situ' formed TiB_2, or both of these at equal amounts (10 vol,%). All the three have been successfully fabricated under essentially the same processing condition, and thereby our final experimental work on the measurement of temperature dependence of dynamic tensile modulus and creep tests is satisfactorily accomplished. Results are analyzed in detail in light of our micromechanics-based description of high-temperature deformation of MMCs, wherein the importance of strongly size-dependent stress relaxation of reinforcing particles is emphasized. The 'hybrid' particulate design and reactive synthesis route to fabrication is promising as advanced technology of high-temperature MMCs. Less

这项研究旨在开发一种新型的铝基金属基复合材料（MMC），其具有颗粒陶瓷增强材料作为先进的高温结构材料，特别关注不同尺寸的陶瓷颗粒在传统材料中的不同作用。颗粒增强 MMC 和弥散强化合金，我们计划在新型“混合”颗粒 MMC 的设计中研究颗粒尺寸对高温的影响含有细（<1μm）和粗（约等于10μm）陶瓷颗粒之一或两者的MMC的刚度和抗蠕变性为此，本工作从Al-Ti反应合成TiB_2/Al MMCs开始。 -B 混合元素粉末，因为这种反应性粉末加工可以在铝基体中原位产生亚微米尺寸的 TiB_2 颗粒。在加热温度高达 1000℃ 的通常加工条件下，最终产品中会形成中间化合物 Al_3Ti，我们的详细研究表明，先前已知的两种中间化合物 AlB_2 和 Al_3Ti 会在存在下分解。熔融铝，形成TiB_2和Al，即AlB_2+Al_3Ti→TiB_2+4Al，这揭示了适当的反应物组成范围， xAl-Ti-2B，其中x【大于或等于】4，用于制备所需的TiB_2/Al两相MMC，临界成分x=4对应于最大27.9vol.%的TiB_2。三种不同的 20 vol.% TiB_2/Al MMC 的制造，颗粒增强材料是原位非常细（<1μm）和粗（【大约等】10μm）“异位”形成TiB_2，或两者均等量（10体积％），所有这三个都在基本相同的加工条件下成功制造，因此我们最终的实验工作是温度测量。根据我们基于微观力学的 MMC 高温变形描述，对动态拉伸模量和蠕变测试的依赖性进行了详细分析，证明了尺寸依赖性应力松弛的重要性。强调了增强颗粒的“混合”颗粒设计和反应合成路线作为高温 MMC 的先进技术是有前途的。