Current Issue : July-September Volume : 2022 Issue Number : 3 Articles : 5 Articles
.e measurement of input and output torque of a precision reducer, the core component of an industrial robot, plays a vital role in evaluating the robot’s performance. .e TMSIS and TMSOS of a vertical cylindrical high-precision reducer detector were designed and investigated in this study to realize the accurate measurement of input and output torque of the reducer. Because a transmission chain connects the torque transducer and the reducer, the characteristics of the inevitable additional torque are analyzed in detail. A torque calibration device is developed to realize the calibration of the torque measurement system. .e readings of the torque calibration device are compared with the data of the instrument’s torque measurement system to realize the instrument’s torque calibration..e improved particle swarm optimization and Levenberg–Marquardt algorithm-based radial basis function neural network is used to compensate for the error of the torque measurement system..eparameters of the RBF neural network are settled according to the characteristics of the additional torque and the torque calibration results. .e experimental results show that the torque measurement accuracy of the torque measurement system can reach 0.1% FS after torque calibration and error compensation....
The combustion and emission characteristics of surrogate diesel fuel homogeneous charge compression ignition (HCCI) with different combustion boundary conditions and n-butanol (NB) mixing ratios are studied in this work. Engine data of a two-stroke low-speed direct-injection marine diesel engine were selected for the reactor. HCCI combustion was achieved by compressing a completely homogeneous mixture of fuel and air. The results show that NO emissions decrease slightly with the increase of initial boundary pressure at a constant equivalence ratio and initial temperature. In addition, the different initial boundary temperature has little effect on NO emission. The results also indicate that the ignition delay time of the mixed fuel rises with the increase of nbutanol mixing ratio. The emissions and reaction rate of NOx reduce significantly with the increase of n-butanol percentage in surrogate diesel fuel and n-butanol mixing combustion at a constant equivalence ratio and total mole fraction. Meanwhile, CO2 emissions also decrease significantly with the increase of n-butanol mixing ratio....
Al/Cu dissimilar joining is a key technology for reducing the weight and cost of electrical components. In this study, the dissimilar friction stir lap welding (FSLW) of a Ni-containing Al alloy to pure Cu was performed, and the effects of the addition of Ni on the weld strength and interfacial microstructure were examined. A thin intermetallic compound (IMC) layer was observed at the Al/Cu weld interface produced by FSLW. The addition of 3 at.% Ni effectively improved the weld strength, although the thickness of the IMC layer increased. The IMC layer formed at the Al/Cu interface without Ni comprised CuAl2 and Cu9Al4 from the pure Al side. In contrast, the IMC layer formed with 3 at.% Ni consisted of (Ni,Cu)Al, CuAl, and Cu9Al4 from the Al side. The addition of Ni eliminated the weak CuAl2/Cu9Al4 interface, thereby improving the weld strength. The results of this study suggest that the strength of the Al/Cu weld can be effectively improved by the thinning of the IMC layer caused by FSLWand the change in interfacial microstructure caused by Ni addition....
Plasma MIG welding is a hybrid welding process that combines two welding methods of conventional metal inert gas (MIG) welding with plasma arc welding. This study investigates the effect of plasma and plasma current values on the microstructure and microhardness properties of welded carbon steel plates. It was found that utilization of the plasma has resulted in a refined microstructure in the heat affected zones (HAZ), and a decrease in microhardness values as compared to conventional MIG welds. This potentially increases the ductility of the plasma MIG weldments. Furthermore, decreasing the plasma currents would result in the decrease of microhardness and grain sizes, thus further increasing the ductility of the welds....
In order to enhance the wear resistance of 304 stainless steel, a FeCrAlNbNi alloyed zone (AZ) was deposited on its surface using laser surface alloying technology, and the wear resistance of the AZ was investigated. The results found that the AZ had a dense and fine structure and no obvious defects, and the microstructure was mainly composed of equiaxed dendrites. A large amount of iron compounds and iron-based solid solutions in the AZ made the average microhardness of the AZ about 2.6 times higher than of the substrate. The friction and wear performance of the AZ at 25 ◦C, 200 ◦C, 400 ◦C and 600 ◦C better than that of the substrate. As far as the AZ was concerned, the abrasion resistance was the best under normal temperature environment. At 200 ◦C and 400 ◦C, due to the repeated extrusion and grinding of the friction pair, the oxide layer formed on the AZ surface was prone to microcracks and peeling off, which reduces the wear resistance. Especially at 400 ◦C, the formation and peeling speed of the oxide layer is accelerated, and the wear resistance is the lowest. However, when the temperature reached 600 ◦C, an Al2O3 layer was formed. And the Al2O3 has greater wear resistance to protect the AZ. At this time, the wear resistance was greatly improved compared to 200 ◦C and 400 ◦C. Therefore, as the temperature increased, the wear resistance of the AZ first decreased and then increased....
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