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The purpose of this paper is to study the pressure response characteristics of the cartridge electromagnetic relief valve, which offers the problems caused by low pressure response and low efficiency in hydraulic plate shearing machines.

First of all the mathematical model of the cartridge electromagnetic relief valve is deduced to analyze the influence of the relevant parameters on the system pressure response. Then experiments are conducted to research the dynamic characteristics on building and relieving pressure. Through comparison of theoretical and experimental research, the results are found.

The results show that the input flow, working pressure, diameter of adjacent damping hole, and spring stiffness of the main valve have great influence on building pressure of the system, and have no influence on relieving pressure, while diameter of damping hole of control cover plate has influence on the building and relieving pressure of the system.

The research results provide powerful theoretical support for the parametric design of the cartridge electromagnetic relief valve in the hydraulic system of plate shearing machine.

The purpose of this paper is to study the influence of different cross-sectional shapes (rectangular, trapezoidal, oval and triangular) and layout forms of oil grooves (radial, circumferential, inclined, compound, helical and double-helical), and determine the optimal section shape and layout form of oil grooves on the temperature field.

Heat conduction theory model was established based on startup characteristics and friction heat principle of hydro-viscous clutch (HVC), and then the theoretical expression of angular velocity of the friction pair and control pressure were deduced, and the heat flux and its distribution on friction disk and separator disk were calculated. Finally, the finite element method was used to solve the temperature field of the friction pair.

The studies show that the circumferential oil groove got the highest temperature, and on the surface of all other structures, hot spots appear with different sizes and temperatures, and the maximum temperature difference in the friction zone is about 3°C, and in the oil groove zone is about 16°C, wherein the compound oil groove has the lowest average temperature. This research shows that the compound oil groove with rectangular cross-section is the best choice for the friction pair.

In this paper, it was found that the compound oil groove with rectangular cross-section is the best choice for the friction pair, and it provided a favorable theory reference and technical support for the structural design of the friction pair and optimized design of the high-power HVC.

Studies on titanium implants have shown that the mechanical properties of the parts are affected by the microstructure characteristic derived from the manufacturing process. The properties of different orientations of specimens under the same process parameters will be different, which should be considered in the application of bone implants. This paper aims to understand the influence of microstructure on micro-hardness, wear and corrosion resistance in different orientations.

The authors manufactured titanium parts and carried out micro-hardness, wear tests and electrochemical corrosion of different orientations under the same process conditions. Then, finally studied the evolution mechanism of the microstructure in different orientations and its influence mechanism on wear and corrosion mechanism.

The melting method makes the grains on the surface in XY orientation finer. The wear mechanism of XY orientation is abrasive wear, that of XZ and YZ orientations are adhesive wear. During corrosion, XY orientation forms a stable passivation film earlier. Compared with XZ and YZ orientations, XY orientation has higher micro-hardness, better wear and corrosion resistance.

In this paper, the microstructure, wear and corrosion resistance of selective laser melted parts were discussed and the differences in different orientations under the same experimental conditions were discussed. The evolution mechanism of the microstructure in different orientations and its influence mechanism on wear mechanism and corrosion mechanism was studied. The mechanical anisotropy of selective laser melted components was discussed.