超磁致伸缩超声换能器的磁路优化设计

Optimal design for magnetic circuit in giant magnetostrictive ultrasonic transducer

为了改善磁路环境,最大限度地降低超磁致伸缩超声换能器的发热,将磁路间隙作为研究对象,采用Maxwell有限元软件对磁路间隙与超磁致伸缩材料(GMM)棒的磁场强度的关系进行了分析,并通过实验对超声换能器的阻抗和振幅,以及GMM棒的温度进行了测量。结果表明:随着磁路间隙的增大,GMM棒的磁场强度和磁场均匀度减小;随着导磁圆筒槽宽的增大,超声换能器的谐振频率基本一致,GMM棒的温度减小。当导磁圆筒的槽宽约为6 mm时,该GMM棒的磁场均匀度最高,机械品质因数最大,这对超磁致伸缩超声换能器的优化设计具有重要的意义。

In order to improve the magnetic circuit environment and minimize the heating of the giant magnetostrictive ultrasonic transducer,the magnetic path gap was taken as the research object,and the relationships between the magnetic path gap and the magnetic field strength of the giant magnetostrictive material(GMM)rod were analyzed by Maxwell finite element software.The impedance and amplitude of the ultrasonic transducer and the temperature of the GMM rod were measured by experiments.Experimental results show that the magnetic field strength and magnetic field uniformity of the GMM rod decrease with the increase of the magnetic path gap.As the slot width of the magnetically permeable cylinder increases,the resonant frequency of the ultrasonic transducer is basically the same,the temperature of the GMM rod is reduced;When the slot width of the magnetic cylinder is about 6 mm,the magnetic field uniformity of the GMM rod is the highest and the mechanical quality factor is the largest,which is of great significance for the optimal design of the giant magnetostrictive ultrasonic transducer.