A precision positioning stage based on a giant magnetostrictive actuator (PPS-GMA) shows nonlinear displacement when it is used in the field of precision positioning control.

Based on the principle of the Villari effect, a force sensor with a giant magnetostrictive material (GMM) as the sensitive element, high linearity, and a large range was studied. A Hall element integrated into the structure was used to detect the magnetic flux density and measure the external force. First, the finite element method was used to verify the validity of the intended magnetization process. Second, an equation for GMM magnetization was derived based on the Jiles–Atherton (J–A) model and the magneto-mechanical coupling effect. The relationships between magnetization and the biased magnetic field, and magnetization and the external force were analyzed under the dynamic coupling model of positive and negative effects. Finally, the influences of various biased magnetic fields and external forces on the sensor output characteristics were determined experimentally. The sensitivity of the designed force sensor was 0.337 mV/N when the bias current was 1.2 A and the preload was 120 N. When a force of 1000 N was applied, the linearity was 0.82%. The experimental results are consistent with the theoretical design values. These research results aid in the development of a highly linear, large-range force sensor. This study provides the theoretical and technical foundations for a high-performance force sensor that can be used in industrial testing.

The structure and principle of the GMM actuator and the new nozzle flapper valve with GMA are presented. The models on dynamic characteristics of the nozzle flapper valve are established. Experimental system testing the control pressure is also constructed. The output performance of the control pressure is done under typical working conditions. Influence on the control pressure is analyzed with varied input pressures and structure parameters. And matching relation of the different parameters is obtained under the best control pressure. The results show that the nozzle flapper valve has wide pressure control performance, good linearity, and high response speed. And theoretical basis is presented to further introduce the GMA nozzle flapper valve into electro-hydraulic servo valve.

The giant magnetostrictive actuator (GMA) with giant magnetostrictive material (GMM) as the core component has wide applications in the field of precision drive and control. In this paper, through the analysis of the GMA coil, the loss and temperature rise characteristics of the GMA have been studied. Then, COMSOL Multiphysics software has been used to model the heat source distribution of the GMM actuator, and the factors affecting the working temperature of the GMM rod have been analyzed. Finally, based on the use requirements of the GMA, magnetic field, and internal temperature distribution characteristics, the heat dissipation scheme of the coil is proposed, and the experimental platform of the GMA with a thermal compensation function is built to verify the temperature characteristics and thermal compensation effect. Studying the internal temperature distribution law of the GMA not only has a guiding significance for the temperature control of the actuator and the design of the cooling system but also reduces the influence of the coil thermal effect on the performance of the transducer and lays the foundation for making full use of the GMM’s potential in high-power transducers.

To study the lubrication and wear reduction characteristics of the QAL9-4 and 17-4pH textured friction pair during water lubrication, the dynamic pressure bearing and cavitation characteristics were analyzed using a computational fluid dynamics method. Then, based on 13 groups of samples with different depths, diameters, and area ratios, relevant frictional and wear tests were carried out. The results showed that the texture affected the pressure distribution in the textured region and improved the liquid film bearing capacity, which increased gradually as the equivalent Reynolds number increased. Under test conditions, the texture parameters had a significant influence on lubrication and wear reduction performance. The optimum texture diameter, the depth, and the area ratio were 300 µm, 40 µm, and 10%, respectively. The wear tracks on the textured specimens were small in size and shallow in depth compared to those on the non-textured specimens. The wear tracks on the textured specimens were regional, and there were more wear tracks in the area without micro-dimples. In summary, it was feasible to apply surface texture to the QAL9-4 and 17-4PH friction pair to improve the lubrication and wear reduction characteristics with water lubrication.