| SM ISO690:2012|
GONCHARUK, Vladislav; PARAMONOV, Anatolii; GROSU, Fiodor; POLIKARPOV, Albert; KOVALI, Alexandr. Alitizing of products from steel and non-ferrous metals. In: Materials Science and Condensed Matter Physics. Editia a 8-a, 12-16 septembrie 2016, Chişinău. Chişinău: Institutul de Fizică Aplicată, 2016, p. 314. ISBN 978-9975-9787-1-2.
|Materials Science and Condensed Matter Physics
Editia a 8-a, 2016
Conferința "International Conference on Materials Science and Condensed Matter Physics" |
8-th Edition, Chişinău, Moldova, 12-16 septembrie 2016
In the industry for alitizing of products from non-magnetizable steels and non-ferrous metals (copper, brass, etc.) different technological methods are used. They allow conducting also and the inverse process - to apply on aluminum pieces the powders of non-ferrous metals (copper, brass, bronze, etc.). It allows providing a possibility of receiving a surface under the soldering. The known ways of alitizing of details have a number of imperfections. Main of them - the formed surface, saturated with aluminum, needs the additional heat treatment leading to diffusive penetration of atoms of aluminum into copper. Besides, for alitizing use very difficult composition of mixes, the layer of alitizing has the small thickness and process has high power costs of annealing. The electrophysical methods based on an electrospark covering of metals and alloys by an aluminum electrode are known. However, such way is inefficient when processing the big areas and often allows skips in processing of a product, and the received surface is non-uniform. The following process of alitizing was developed: the device for alitizing represents the alternating current motor containing the stator winding (creating the rotating magnetic field in the range of 2535 mT) which is connected to source of alternating current. Instead of rotor the pipe from conducting non-magnetic material is placed in the center of the engine. In it dispose the workpiece of cylindrical form. Mobile electrodes and powder of aluminum place in the camera, formed by pipes and rubber rings. Connect the processed part (cathode) and external pipe (anode) to source of direct current of 40-90 V. At energization on stator winding, the rotating magnetic field is created. The deposited powder, thanks to mobile electrodes, comes to condition of fluidization. At connection to the rectifier of the processed detail (cathode) and external pipe (anode), mobile electrodes and powder initiate the spark discharge at which the strong metal layer of any adjustable thickness is applied on the processed detail. Process not need in separate heat treatment of product, therefore has low energy costs. Thanks to the spark discharge metals strongly connect among themselves. Time of processing of the 10th centimetric zone of copper pipe does not exceed 3-5 minutes. Considering possibility of movement of long and dimensional cylindrical detail which is passed via the camera with sealants, time of processing of 1 meter of pipe of any length does not exceed 50 minutes. For processing of in advance chosen zones, temporarily are applying coverings from rubber on unnecessary zones or dielectric films with unilateral glue covering. During researches coverings have been received: copper on aluminum and vice versa, bronze on aluminum, copper with aluminum on aluminum. By regulation of technology parameters were received coverings in the range of thickness of 0,1÷1,5 mm. Receiving and thicker hilly coverings, for example, for creation of catalysts, is possible.