BT16钛合金渗氢后的针状物生成及演化过程

为了深入了解渗氢对BT16钛合金组织的影响,以获得具有优良冷镦性能的组织,采用光学显微(OM)分析和X射线衍射(XRD)分析等方法,研究了BT16钛合金渗氢后的微观组织和相组成。结果表明：BT16钛合金在780 ℃渗氢的过程中发生了α+β相到β相的转变,冷却后生成了魏氏体组织,α相在不同通氢时间的试样中均存在,且含量随通氢时间的增加而降低,渗氢过程中出现了氢化物相。说明渗氢导致BT16钛合金α+β相到β相的临界转变温度降到800 ℃以下,氢含量影响了氢化物的存在形式,随着氢含量的增加,TiH相最先出现,随后出现TiH_1.5和TiH₂相,这些钛氢化合物均为针状。

Formation and Evolution Process of Needle Hydride of BT16 Alloy After Hydrogenation

To understand deeply the influence of hydrogenation on the BT16 alloy microstructure and obtain a microstructure with good properties of cold heading, optical microscopy (OM), and X ray diffractometry (XRD) are used to analyze the microstructure and phase composition of BT16 alloy after hydrogenation. The results show that the BT16 alloy phase transforms froms α+β to β at 780 ℃ in the process of hydrogenation, and Widmanstatten structure is generated after cooling. The α phase can be found in all samples with different hydrogenation time, and its content decreases as the hydrogenation time increases; hydrides appear in the process of hydrogenation. This suggests that because of hydrogenation, the transition temperature at which the BT16 alloy phase transforms from α+β to β drops below 800 ℃, and the hydrogen content influences the existing form of hydrides. As the hydrogen content increases, the TiH phase appears earlier, the TiH_1.5 phase and TiH₂ phase appear later, all of which are needle hydrides.