Patent RU-2746191-C1 (RU)
Title: Device for electrochemical formation of ceramic-like coatings on the surfaces of products made of valve metals
Inventor: Borisov Anatolij Mikhajlovich
IPC: C25D11/00
Filed: 2020-07-03
Granted: 2021-04-08
Abstract: FIELD: galvanotechnics.  
     SUBSTANCE: invention relates to the field of electroplating and can be used to form ceramic-like wear- and heat-resistant, electroinsulating, corrosion-protective and decorative coatings on complex-profile surfaces of products made of valve metals in various industries. The device contains a power supply with two terminals, an electrolyte bath with the product, two batteries of electric capacitors, four thyristors with four assemblies of control circuit galvanic isolation, a software and hardware control system, the cathode of the first and the anode of the second thyristors are connected to the second plate of the first battery, and the cathode of the third and the anode of the fourth thyristors are connected to the second plate of the second battery, the anode of the first and the cathode of the fourth thyristors are connected to the second terminal of the power supply and to the bath body,  the product is connected to the cathode of the second and the anode of the third one, to the control transitions of the four thyristors the outputs of the four galvanic isolation nodes are connected, to the inputs of which the outputs of the mode control system are connected, the first input of which is connected to the second plate of the first battery, and the second input - to the second plate of the second battery; at the same time, the device is equipped with the fifth, sixth, seventh and eighth thyristors with galvanic isolation assemblies of control circuits, the first and second non-contacting electric current sensors, an additional controlled counter electrode and its software and hardware control system, while the first sensor is placed in the electrolyte outside the product, and the second sensor and the counter-electrode-inside the product cavity, the sensor outputs are connected to the inputs of the anti-electrode control system, the anode of the fifth thyristor is connected to the cathodes of the second and sixth ones and the anode of the third one, and the cathode of the fifth thyristor is connected to the anode of the second one, the anode of the sixth thyristor is connected to the cathode of the third one, the outputs of the two galvanic isolation nodes are connected to the control transfers of the fifth and sixth thyristors, to the inputs of which the outputs of the mode control system are connected, anode of the seventh and eighth cathode of the thyristor is connected to the counter electrode, while the cathode of the seventh and the anode of the eighth thyristors are connected to the bath, outputs of two galvanic isolation assemblies are connected to the control transfers of the seventh and eighth thyristors, to the inputs of which the outputs of the counter electrode control system are connected.  
     EFFECT:  technical result is to improve the quality of coatings formed on complex-profile surfaces of products, including those with internal cavities, and to expand the possibilities of the process of their application by using micro-arc oxidation mode cycling and introducing an additional controllable counter electrode placed in the inner cavity of the workpiece. 
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