technical science
PhD in Technical sciences Khafizov Ildar Ilsurovich
Kazan federal
university
INFLUENCE OF THE DESIGN OF THE
EQUIPMENT AND AUTOMATION EQUIPMENT OF ELECTRIC METHODS ON PROCESSING
IMPROVEMENT OF QUALITY
Let's consider three basic elements of the electrochemical machine,
which are most subject to corrosion:
·
the working surfaces which have been close located to the cathode and
the processed detail (the working camera and basic surfaces of the detail and
the adaptation);
·
constructive elements of the machine remote from the working camera, for
example bed, the service equipment into
which the pump for supply of electrolyte and pipelines (the working camera and
basic surfaces of a detail and the adaptation) enters.
When electrolyte proceeds on a detail surface as, for example, at a of shovels, its stream needs to be limited
to the sizes of a working gap. In this case directing for a stream and actually
all working camera can be made of blocks of acrylic plastic or plexiglass. This
material doesn't react with acid and alkali solutions, and the working camera
can be rather rigid to sustain electrolyte pressure. The same material can be
used when electrolyte is brought perpendicular to a surface of a detail and
taken away through a hollow electrode, as at an insertion of openings with a
stream. When processing without a stream electrolyte moves through a hollow
electrode and at an exit from a gap is under atmospheric pressure. In this case
the protection is only protection from spraying and its design can be not
rigid; for example, the leaf from polyethylene will be quite satisfactory. In
certain cases it is desirable to produce the working camera from metal. For these purposes it became possible to use
low-carbonaceous provided that internal walls will be reliably protected. Coverings from pitch have to be reliable,
and in this case it is possible to
recommend not being dissolved epoxies. To minimize corrosion of the working
camera, when the machine doesn't work, it is desirable to wash out at the end
of processing it water. Electrodes sometimes project so that condensing rings
under pressure of electrolyte nestled on a surface of a detail and the tool,
providing full sealing of a working zone, without application of additional
protections.
The material used for production of clips of a detail during processing,
is exposed to anode etching and therefore the titan owing to his anode
passivity is better to use. Samples in which deep openings were stitched, were
clamped in the titanic block: via this adaptation current was brought to
samples and in the course of processing the surface of the titan wasn't exposed
to etching. The titanic cartridges applied at electrochemical sharpening can be
other example.
Such elements as heads of bolts, can be protected by organic coverings,
for example, polyethylene or epoxies.
In the presence of electrolyte on the diverse metals being in contact,
especially when the machine doesn't work, strong bimetallic corrosion can be
observed. Therefore it is important that contacting metals not so differed on
the electrochemical potentials. For example, the metals being in contact, have
to be picked up so that tension of a being formed galvanic cell didn't exceed
0,25 V.
The working camera in which there is a tool and a detail, contains the
considerable volume of the electrolyte, capable to come into contact to machine
elements, thanks to its inevitable spraying and sedimentation on unprotected
surfaces. Corrosion can be considerable because of a free access of air to a
metal surface, and also ability of the settled liquid to evaporation that, in
turn, increases concentration of the corrosion environment.
The elements of the machine being in close proximity to the working
camera, can be made of a corrosion-resistant material, for example, stainless
steel, but probably it is better to do them of cast iron or low-carbonaceous
steel and to protect paint or a plastic covering. Sheeting’s are put on big
surfaces with a brush or dispersion. It is possible to give chlorine rubber
which on the prepared surface of metal bring in the following order as an
example: primer, bottom and top (last) coverings. Thickness of all covering is
approximately equal 0,25 mm. Epoxy and polyurethane coverings also are
satisfactory. It is necessary to wash often walls as the few coverings provide
full protection for a long time. Directing machines, for example
electrochemical turning , cover with greasing which protects open surfaces, and
its protective properties can be raised by addition of inhibitors.
Applied methods of division of metals allow, generally to carry out
procuring operations where high precision and quality of a blanket which are
provided at the subsequent stages of processing demanding considerable
allowances on process, having high labor input and specific power consumption
isn't required.
2 . Electrochemical processing provides process accuracy, but
demands the subsequent operations for achievement of the set purity.
3 . Known designs of the disk tool for division give the big width of a
groove or don't provide the demanded accuracy of process, quality of a blanket.
4. The
available equipment for division of materials isn't equipped with demanded
automation equipment of process, including elements of adaptive management with
correction of modes on the set regularities.
5 . It
is necessary to develop technological process, the equipment and means of
technological equipment to division of materials applying development.
The
list of the used sources
1. Khafizov
I.I. An intensification of the combined process of electrodiamond processing of
metals and alloys and improvement of quality of a workability of a surface of
metals//Technological support of quality of cars and devices: collection of
articles III of the International scientific and practical conference. Penza:
2006-Pages 64-66.
2. Khafizov
I.I. Avtoref. yew. PhD.Tech.Sci. Publishing house of Public Educational
Institution of Higher Professional Training VGTU, 2007, 18 c.
3.
Smolentsev V.P. Sukhorukov N. V. Physical bases and technological application
of electrocontact process. Voronezh 1998, 148ñ.