Ultrasonic welding is an effective ways to achieve a non-reactive/immiscible heterogeneous metal connection, such as the connection of magnesium alloy and titanium alloy. But the thermal mechanism of magnesium alloy/t...Ultrasonic welding is an effective ways to achieve a non-reactive/immiscible heterogeneous metal connection, such as the connection of magnesium alloy and titanium alloy. But the thermal mechanism of magnesium alloy/titanium alloy ultrasonic welding has not been defined clearly. In this paper, the experimental and the finite element analysis were adopted to study the thermal mechanism during welding. Through the test, the temperature variation law during the welding process is obtained, and the accuracy of the finite element model is verified. The microscopic analysis indicates that at the welding time of 0.5 s, the magnesium alloy in the center of the solder joint is partially melted and generates the liquid phase. Through the finite element analysis, the friction coefficient of the magnesium–titanium ultrasonic welding interface can be considered as an average constant value of 0.28. The maximum temperature at the interface can exceed 600 ℃ to reach the melting point temperature of the magnesium alloy. The plastic deformation begins after 0.35 s and occurs at the magnesium side at the center of the interface.展开更多
美国石油协会组织于2012年出版的API Standard 53标准相对于之前的API RP53,对水下防喷器的应急备用部分做出了强制性要求,需要配备自动剪切以及失效安全两种系统。针对该要求,目前现役的大部分水下防喷器控制系统需要进行升级改造。本...美国石油协会组织于2012年出版的API Standard 53标准相对于之前的API RP53,对水下防喷器的应急备用部分做出了强制性要求,需要配备自动剪切以及失效安全两种系统。针对该要求,目前现役的大部分水下防喷器控制系统需要进行升级改造。本文通过对规范的解读,对自动剪切及失效安全功能进行系统原理上的逐一分析,提出一种升级改造的设计思路。展开更多
基金Supported by National Natural Science Foundation of China(Grant Nos.U1764251,51775160)Fundamental Research Funds for the Central Universities of China(Grant No.DUT19LAB24)
文摘Ultrasonic welding is an effective ways to achieve a non-reactive/immiscible heterogeneous metal connection, such as the connection of magnesium alloy and titanium alloy. But the thermal mechanism of magnesium alloy/titanium alloy ultrasonic welding has not been defined clearly. In this paper, the experimental and the finite element analysis were adopted to study the thermal mechanism during welding. Through the test, the temperature variation law during the welding process is obtained, and the accuracy of the finite element model is verified. The microscopic analysis indicates that at the welding time of 0.5 s, the magnesium alloy in the center of the solder joint is partially melted and generates the liquid phase. Through the finite element analysis, the friction coefficient of the magnesium–titanium ultrasonic welding interface can be considered as an average constant value of 0.28. The maximum temperature at the interface can exceed 600 ℃ to reach the melting point temperature of the magnesium alloy. The plastic deformation begins after 0.35 s and occurs at the magnesium side at the center of the interface.
文摘美国石油协会组织于2012年出版的API Standard 53标准相对于之前的API RP53,对水下防喷器的应急备用部分做出了强制性要求,需要配备自动剪切以及失效安全两种系统。针对该要求,目前现役的大部分水下防喷器控制系统需要进行升级改造。本文通过对规范的解读,对自动剪切及失效安全功能进行系统原理上的逐一分析,提出一种升级改造的设计思路。
