铝熔体中超声辐射杆的空蚀实验及机理研究

发布时间：2018-04-04 12:31

本文选题：超声辐射杆　切入点：空蚀　出处：《华中科技大学学报(自然科学版)》2015年02期

【摘要】：超声辐射杆在铝熔体中产生空蚀严重制约其使用寿命及铝熔体的纯净度,针对这一问题,进行了铝熔体钛合金超声辐射杆空蚀试验,采用失重法及熔体Ti元素检测法描述了辐射杆空蚀进程,运用扫描式电子显微镜(SEM)及能谱仪对空蚀试样进行宏/微观形貌观察及成分检测,探讨空蚀各阶段机理.结果表明:辐射杆空蚀以端面为主,随时间推移由端面中心逐渐在横向辐射扩张并在纵向加深;空化孕育期是由于空化泡溃灭冲击辐射杆产生塑变引起的;空化加速期钛合金基体与铝熔体反应生成Al3Ti,该物质硬而脆的特性使钛合金基体在空化冲击作用下脱落是导致失重率快速上升的主要原因;钛合金辐射杆在铝熔体中的空化破坏是由空化泡溃灭冲击及化学腐蚀共同作用导致的.
[Abstract]:The cavitation corrosion of ultrasonic radiating rod in aluminum melt seriously restricts its service life and purity of aluminum melt. Aiming at this problem, the cavitation test of ultrasonic radiation rod of titanium alloy in aluminum melt is carried out.The cavitation process of radiation rod was described by weightlessness method and Ti element detection method. Scanning electron microscope (SEM) and energy spectrometer (EDS) were used to observe the morphology and composition of cavitation specimen, and the mechanism of cavitation was discussed.The results show that the cavitation erosion of the radiating rod is dominated by the end surface, which expands gradually from the center of the end face and deepens in the longitudinal direction with time, and the incubation period of cavitation is caused by the plastic transformation of the radiation rod caused by the collapse of cavitation bubble and the impact radiation rod.The Al _ 3Ti was formed by the reaction of titanium alloy matrix with aluminum melt during the accelerated cavitation period. The hardness and brittleness of the material caused the matrix to fall off under cavitation impact, which was the main reason for the rapid increase of weight loss rate.The cavitation failure of titanium alloy radiation rod in aluminum melt is caused by the combined effect of cavitation bubble collapse and chemical corrosion.
【作者单位】：中南大学机电工程学院;中南大学高性能复杂制造国家重点实验室;
【基金】：国家重点基础研究发展计划资助项目(2010CB731706,2012CB619504)
【分类号】：TG292

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