Blocky and columnar microstructures and the influence on mechanical behaviors of a hot-pressed Nb-23Ti-15Al alloy
Blocky and columnar microstructures and the influence on mechanical behaviors of a hot-pressed Nb-23Ti-15Al alloy
复制标题
热压Nb-23Ti-15Al合金的块状和柱状显微组织及其对力学行为的影响
DOI：
10.1016/j.matdes.2015.08.089
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发表时间：
2015
影响因子：
8.4
通讯作者：
Zheng Qi
中科院分区：
文献类型：
--
作者：
Shi Zhiwu;Wei Hua;Zhang Hongyu;Jin Tao;Sun Xiaofeng;Zheng Qi
热压Nb-23 Ti-15 Al（at.%）合金的显微组织和力学行为合金进行了研究。结果表明，随着热压温度的不同，该合金呈现出明显不同的组织形态：块状组织或柱状组织。在较低的热压温度下，亚稳的σ相与β相反应生成块状δ相;在较高的热压温度下，δ相直接从过饱和的β相中析出，择优取向关系为[212] δ//[001] β和（02 1 <$）δ//（110）β，形成柱状组织。柱状组织能有效地抵抗变形，阻止裂纹的萌生和扩展，从而提高了合金的显微硬度和韧性。
The microstructure and mechanical behaviors of a hot-pressed Nb–23Ti–15Al (at.%) alloy have been investigated. The results indicate that with different hot-pressing temperatures, the alloy presents remarkably different microstructural morphologies: blocky microstructure or columnar microstructure. At lower hot-pressing temperature, the blocky δ phase is formed by the reaction of the metastable σ phase and the β phase; at higher hot-pressing temperature, the δ phase directly precipitates from the supersaturated β phase with preferred orientation relationships of [212] δ//[001] β and (02 1¯) δ//(110) β to form columnar microstructure. The columnar microstructure leads to higher microhardness and better toughness, for the reason that the columnar microstructure could resist deformation of the alloy effectively, and impede initiation and propagation of cracks.