High-cycle fatigue properties of Al-based composites reinforced with in situ TiB2 and Al2O3 particulates
High-cycle fatigue properties of Al-based composites reinforced with in situ TiB2 and Al2O3 particulates
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DOI：
10.1016/j.msea.2004.07.021
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发表时间：
2004-11
期刊：
影响因子：
6.4
通讯作者：
S. Tjong;G. Wang;G. Wang
中科院分区：
文献类型：
--
作者：
S. Tjong;G. Wang;G. Wang
通过反应热压Al-TiO2-B体系中的TiO2、Al和B粉末以及Al-TiO2-B2O3体系中的TiO2、Al和B2O3粉末，合成了原位TiB2和Al2O3颗粒增强的铝基复合材料。脆性金属间Al3Ti相也原位形成，并且不均匀地分布在复合材料的Al基体中。在完全反向拉伸压缩载荷下评估了这种原位复合材料在室温下的高周疲劳（HCF）性能。大体积含量细化TiB2和Al2O3颗粒增强的复合材料在应力控制条件下表现出优异的疲劳极限和寿命。然而，尺寸为几微米的金属间Al3Ti块不利于TiB2和Al2O3颗粒增强的原位复合材料的抗HCF性能。这是由于 Al3Ti 块在循环过程中断裂，从而成为裂纹萌生位点。
Aluminum-based composites reinforced with in situ TiB2and Al2O3particles were synthesized through reactive hot pressing of TiO2, Al and B powders in Al–TiO2–B system, and TiO2, Al and B2O3powders in Al–TiO2–B2O3system. Brittle intermetallic Al3Ti phase was also formed in situ and distributed non-uniformly in Al matrices of the composites. The high-cycle fatigue (HCF) resistance of such in situ composites at room temperature was evaluated under fully reversed tension–compression loading. The composites reinforced with large volume content of fined TiB2and Al2O3particles exhibited excellent fatigue endurance limit and life under stress-controlled condition. However, intermetallic Al3Ti blocks with a size of several micrometers were detrimental to the HCF resistance of in situ composites reinforced with TiB2and Al2O3particles. This is due to the fracture of Al3Ti blocks during cycling, thereby, acting as crack initiation sites.