The good DC magnetic properties can be achieved for 1J50 soft magnetic alloy by applying high temperature hydrogen annealing. Annealing process parameters, e.g., atmosphere, soaking temperature, and time, are critical to soft magnetic properties. Qualitative results had been done for years. However a quantitative research among process parameters, microstructure, and magnetic properties can be more comprehensive and specific. In this study, a serial of experiments for 1J50 samples under the Chinese national standards. The influence of annealing temperature and socking time on DC magnetic properties and microstructure of the samples has been investigated on DC magnetic properties and microstructure of samples. The result shows that annealing process parameters have a nonlinear effect on the development of material microstructure and magnetic properties. Furthermore, the models among magnetic property, grain size, and process parameters have been built to quantitatively describe the interrelationship in between.

Based on the fact that damping alloys can convert mechanical energy into heat energy and dissipate it in materials and the environment, high-strength Fe-Mn damping alloys were used to replace common gear materials to absorb vibration-generated energy from the vibration source. A high-strength Fe-Mn damping alloy was developed. Taking two kinds of new damping alloy materials and common materials as the research object, a constitutive model of the Fe-Mn damping alloy material was established, the temporal increment step form of the three-dimensional constitutive model was deduced, and a user-defined material (UMAT) subprogram of the damping constitutive alloy model was developed by FORTRAN language. Based on the three-dimensional contact non-linear finite element model of the gear shaft-bearing box, a transient dynamic analysis was conducted using a non-explicit algorithm to obtain the responses of vibration acceleration on the gear reducer box, which can verify the correctness of the proposed constitutive model. The vibration experiments of the gear reducer made of the above-mentioned materials were carried out under different working conditions. The vibration reduction of the developed high-strength Fe-Mn damping alloy can be certificated by comparing the vibration acceleration response and the measuring point temperature of the gear reducer house prepared by different alloys.

A novel compound epicyclic gearing that combines a planetary gear train with a differential gear train is designed for an electrical propulsion system of underwater unmanned vehicles. This epicyclic gearing can transform a single input into two counter-rotating outputs with equal torque amplitudes and speeds. Based on the analysis method of power flow in the differential gear train, the character of the power flow of the compound epicyclic gearing was determined. After comparing with the power distribution of input flow, the condition of this mechanism without power recirculation was investigated. Because the reactive torque of the motor stator is balanced by the torque on ring gear of planetary gear train, no net torque acts on the vessel being propelled.