Patent RU-2746505-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: C25D11/02
Filed: 2020-07-03
Granted: 2021-04-14
Abstract: FIELD: galvanotechnics. 
     SUBSTANCE: invention relates to the field of electroplating, in particular to micro-arc oxidation, 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, and can be used in machinebuilding and instrument-making, aviation, radio-electronic and other industries. The device contains a power supply with two terminals, an electrolyte bath with a workpiece, two banks of electric capacitors, four thyristors with four assemblies of galvanic isolation of control circuits, a software and hardware mode control system, while the first battery plates are connected to the first terminal of the power source, 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 source and to the body of the bath, the product is connected to the cathode of the second and the anode of the third thyristors, the outputs of four galvanic isolation assemblies are connected to the control transfers of the four thyristors, 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, while the device is equipped with the fifth, sixth, seventh and eighth thyristors with galvanic isolation assemblies, the first and second no-contact electric current sensors, additional automatically controlled counter electrode and its software and hardware control system, the first sensor being located in the electrolyte outside the inner cavity in the product, and the second sensor and the counter electrode inside this cavity, the sensor outputs are connected to the inputs of the counter 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, outputs of two nodes are connected to the control transfers of the fifth and sixth thyristors galvanic isolation, to the inputs of which the outputs of the mode control system are connected, the anode of the seventh and the cathode of the eighth thyristors are connected to the counter electrode, while the cathode of the seventh and the anode of the eighth thyristors are connected to the bath, the outputs of two galvanic isolation nodes 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, in this case, while both control systems are connected by a bidirectional serial information channel.   
     EFFECT:  technical result is to improve quality of ceramic-likehardening coatings on complex-profile surfaces of products, including those with internal cavities, and to expand the possibilities of the electrochemical process of their application by using cycling of microarc oxidation modes and the introduction of an additional, automatically controlled counter-electrode placed in the hollow space of the product. 
     1 cl, 1 dwg