Sialon ceramic tool material has become one of the most ideal materials for the high-speed cutting of superalloy materials. However, studies on the geometric structure of sialon ceramic solid end mill is lacking at the present. In this work, the geometric structure of sialon ceramic end mills was designed for difficult-to-machine nickel-based superalloy materials. The cutting force and heat, flank wear and machined surface quality were analyzed to study the effect of the main parameters on tool performance. The results showed that the end mill experienced severe flank wear and chipping, which were the leading cause of its failure during high-speed cutting. The cutting force and temperature decreased gradually with the increase in the helix angle. With the increase in the rake angle, the flank wear and the quality of the machined surface of the specimen first decreased and then increased. With the increase in the relief angle, the cutting temperature of the ceramic end mill gradually decreased, and the cutting force and the machined surface roughness showed an initial decrease and then increased. When the helix angle, rake angle and relief angle were 35°, −15° and 12°, respectively, the sialon ceramic end mill exhibited the best cutting performance and obtained better machined surface quality in the nickel-based superalloys.
The tractor-model washing system is usually used in the technical process of maintenance for the vehicles in urban mass transit system and its efficiency is lower. On the basis of study and investigation, a self-traction model system has been developed. After a vehicle set is driven by its motors to go through the washing section and the trainset stopped at certain place, the mobile robotic platform will move to the vehicle set by its two propulsive wheels driven by VVVF (variable speed and variable voltage) inverter. The washing motion of shape-adaptation and the synchronized drive of robotic platform are implemented by neutral cell self adaptive algorithm and Cross-Coupling Control (CCC) algorithm. A variable quantity water control algorithm is designed for the goal of energy-saving and water-saving. Several-year actual running shows that it can work effectively and durably.
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