Authors: Wen Zhi Wen Li Hani Gupta
Publish Date: 2007/10/01
Volume: 42, Issue: 19, Pages: 8139-8143
Abstract
Development of intermetallic compounds in Ti–Al alloys for hightemperature structural applications has long been impeded due to their embrittlement To overcome the embritttlement it is necessary to understand thoroughly its chemical bonding nature and the resultant phase transformation behavior In this study based on the Empirical Electron Theory of Solids and Molecules EET effects of interstitial impurities on the valence electron structures and phase transformations in the intermediate Ti–Al alloys were investigated It was demonstrated that for such alloy systems because interstitial impurities can enhance the hybridization states of Ti and Al atoms the valence electron structures of various phases became considerably anisotropic As a result some phase transformations at high temperatures was hindered leading to the occurrence of complex metastable phases at the room temperature Such theoretical calculations clarified some unclear results from experimental observations in the literature
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