Fiabilitate si Durabilitate – Fiability Durability No 2 2014 [607417]

Fiabilitate si Durabilitate – Fiability & Durability No 2/ 2014
Editura “Academica Br âncuși ” , Târgu Jiu, ISSN 1844 – 640X

3 THE BLADES OF TURBINES PROCESSED BY ELECTRICAL
EROSION.

Drd. Ing. Ioan BADIU, Technical University of Cluj -Napoca
Prof.univ.dr.ing. Marcel S.POPA, Technical Un iversity of Cluj -Napoca

ABSTRACT : Processing by electro erosion EDM (Electric Discharge Machining) is a process that uses a
series of electric discharges (sparks) to erode material from the work piece. Processing by electro erosion
exploded. EDM (Elec tric Discharge Machining) has established itself as a precision technology chosen more
for what can be done than for what they can not do conventional machines. EDM (Electric Discharge
Machining) is a processing technology that enabled a multitude of new applications, the importance of
increasingly high is placed on the graphite electrode material used. Although there are several methods to
determine the correct material for an application, we believe that there are five factors that can mean the
differenc e between success and failure, between profit and loss. These factors are: metal removal rate, wear
resistance, surface finish, the processability, the cost of the material.

KEY WORDS : EDM(Electric Discharge Mach ining) , metal removal rate, blades of turbines.
1.INTRODUCTION

The steam turbine is a rotary engine thermal machine that transforms the enthalpy of
steam into mechanical energy available to the turbine coupling. The transformation is done by
means of rotor blades mounted on a rotating joint . Currently, steam turbines completely
replace steam engines due to higher thermal efficiency and a power / weight ratio better. Also,
the rotation of the turbine is obtained without a translational mechanism parts, such as
connecting rod -crank mechanism, is optimal for driving electric generators – approx. 86% of
electric power produced in the world is generated using steam turbines. Steam with high
pressure and temperature is expanded in the stator vanes, also called nozzles, to a lower
pressure. Energy s team enthalpy characterized by kinetic energy is converted. High velocity
steam flow direction is changed by means of blades, resulting in a force acting on the blades,
which creates a force on the rotor time. It rotates at a certain rotational speed, torq ue
delivering power as mechanical work per unit time. The turbines are classified according to
different criteria:

1.1. After the thermodynamic principle of operation.
Turbines action – which all fall enthalpy of steam turbines available is converted into
kinetic energy only stator vanes, rotor blades having only meant to transform the kinetic
energy of steam into mechanical energy. Steam turbines action is characterized by
diaphragms. Reaction turbines -with enthalpy drop is converted into kinetic energy pa rtially
stator blades, vanes called and the rest of the rotor blades.
As the steam expands in the rotor blades, the tangential force acting on both of the
deviation is produced by the steam, and the reactive force due to the acceleration of the jet.
Turbi ne combined with action steps that have both (usually in the high -pressure) and
speed of reaction (low pressure side).The fact that the steam is expanded fully, or not nozzles,
that is, a stage action or reaction is strictly depends on the profile shape of the nozzles and
blades, as illustrated in the figure.

Fiabilitate si Durabilitate – Fiability & Durability No 2/ 2014
Editura “Academica Br âncuși ” , Târgu Jiu, ISSN 1844 – 640X

4 1.2.After the number of steps.
Single -stage turbines – that are acting on the turbine enthalpy drop is converted in one
step. An example is the Laval turbine. These turbines are simple and inexpensiv e, but can
process only a relatively small enthalpy drop and can deliver low power at high speeds,
sometimes more than 300 rev / s. The need for a gearbox limited practical applications.
Turbine overlapping – also known as turbine speed or turbine Curt is, which action
turbine which fall enthalpy of the steam is transformed into kinetic energy in a single crown
of nozzles (as a single -stage turbine), but the kinetic energy is converted into mechanical
energy in two or three crowns fixed on the rotor blad es. Between crowns are placed wreaths
rotor blades fixed rectifiers, which conveniently orient the jet of steam coming out of the
crown (step) before.
Curtis turbines can process enthalpy drop greater than single -stage turbines, but have a
lower internal efficiency. Multi -stage turbines – also called pressure -stage turbine, where the
enthalpy of the steam is converted in several steps arranged in series. They can be so acting,
and with the reaction. Enthalpy drop per stage is lower resulting in lower engin e speeds, when
operating the preferred electrical generators, operating at 50 rpm / s and 25 rpm / s in Europe,
namely at 60 rpm / s and 30 rpm / s USA. These turbines can process large enthalpy drop can
be built for very high power and have higher effect ive yields. They, however, complicated
construction, large masses are expensive and demanding operation and maintenance.

1.3.After the direction of flow of steam.
Axial turbines – where the general flow of the steam is parallel to the axis of rotation
of the rotor. They may be of any type described above. Acting axial turbines are called Rateau
turbine and the turbine jet Parsons. These turbines have several advantages: they have a more
favorable distribution efforts, construction, installation and adjust ment simple and can be built
to very high power advantages they provide most widespread. Radial turbines – the general
flow of steam which is in a plane perpendicular to the axis of the turbine. Centripetal or
centrifugal flow can be. They can be the actio n or reaction, single -stage or multistage. The
best known is Ljungström turbine, which is a reaction turbine Multistage centrifugal flow,
paddles mounted alternately on two rotors that rotate in opposite directions. Radial turbines
have a very compact cons truction, but due to unfavorable schedule requests can not be
constructed for very high power.

1.4. After the final pressure.
Condensing turbines, where steam is expanding to a pressure below atmospheric
pressure achieved by a capacitor is discharged out of the steam turbine. Turbine emitted into
the atmosphere from which the steam is discharged directly to the atmosphere, at a pressure
slightly less than atmospheric pressure. These turbines have low thermal efficiency and are
used only as auxiliary turbi nes to power very small.Back pressure turbine, wherein steam
exhausted from the turbine is at a pressure greater than atmospheric pressure, to its use for
technological purposes or heating (heating industrial).

Fiabilitate si Durabilitate – Fiability & Durability No 2/ 2014
Editura “Academica Br âncuși ” , Târgu Jiu, ISSN 1844 – 640X

5 1.5. After the sampling the steam outlets.
Turbine without sampling the entire amount of steam entering the turbine goes
through all the steps. Unadjusted doses turbines, where some of the steam is taken of the stage
and used for regenerative preheating boiler feed water. The pressure at the outle ts is not
necessary to have fixed values (to be controlled), where their name. Turbine socket set, where
some of the steam is taken of the stage and used for technological purposes or for heating.
The pressure at the outlet it is necessary to have fixed va lues.

1.6.The construction.
Nozzles are channels whose section varies continuously after a certain law to ensure
desired speed of steam. Usually, these channels are made by joining a number of fixed blades,
the space between each two blades forming a noz zle, resulting in a series of nozzles. If the
speed that you need to reach the steam leaving the nozzle is subsonic, using convergent
nozzle whose section decreases continuously from entry to exit.
If you need a supersonic speed, using convergent -diverge nt nozzles (Laval nozzles),
whose section decreases to a minimum, in which section the speed of sound is reached, and
further section increases, further increasing speed until desired value, the fact that
corresponding channel section.The blades are parts that converts the kinetic energy of steam
into mechanical energy. They consist of an active part of the blade and the blade disc
clamping part (acting turbines) and the drum (the ones with the reaction), the foot of the
blade. The blade of the blade serves to change the direction of the steam to extract energy
from it. For this purpose blade is shaped aerodynamic profiles used are relatively thick and
high curvature. And the blades profile shape depends on the desired flow.
The turbine blades action is ne eded in the channel inter color chart has a substantially
constant section and those with reaction requires convergent -divergent or convergent
channels. The speed of the steam (which is a vector) has a value that is related to the nozzle,
which is fixed sp eed vector in this case the steam is denoted by c, and another value if related
to the blades, which move at the speed u velocity vector it being noted in this case steam w.
The three vectors: c, w, and u forms a triangle, called velocity triangles.
For a given speed in the speed u is proportional to the radius of the circle on which the
moving section of the blade. Size speed c does not depend on radius, velocity triangles that
form the radius changes. Blade profile shape is effective when input and outp ut directions
correspond to the directions of steam from the triangle of velocities. If the blades are not too
long, radius does not vary much, either triangles do not differ much, so for simplicity
technology, using constant -profile blades. However, if th e blades are long and are intended
optimal performance, the profile of the blades should vary with range, yielding the so -called
variable profile blades (twisted blades).

Fiabilitate si Durabilitate – Fiability & Durability No 2/ 2014
Editura “Academica Br âncuși ” , Târgu Jiu, ISSN 1844 – 640X

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Fig. 1. Single -stage turbine.
Fig. 2 . Profile of turbine blade action.

Fig. 3. Profile of reaction turbine blade.
Fig. 4 . Constant turbine blade profile.

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Fig. 5. The variable profile turbine blade Fig. 6 . Installation of a steam turbine.

2.THERMAL PHENOMENA OCCURRING IN THE ELECTRICAL
EROSION.

The principle of spark erosion is simple. The work piece and tool are placed in the
working position in such a way that they do not touch each other. They are separated by a gap
which is filled with an insulating fluid. The cutting process therefore takes place in a tank.
The work piece and tool are connected to a D.C. source via a cable. There is a switch in one
lead. When this is closed, an electrical potentia l is applied between the work piece and tool.
At first no current flows because the dielectric between the work piece and tool is an
insulator. However, if the gap is reduced then a spark jumps across it when it reaches a certain
very small size. In this p rocess, which is also known as a discharge, current is converted into
heat. The surface of the material is very strongly heated in the area of the discharge channel.
If the flow of current is interrupted the discharge channel collapses very quickly.
Conse quently the molten metal on the surface of the material evaporates explosively
and takes liquid material with it down to a certain depth. A small crater is formed. lf one
discharge is followed by another, new craters are for med next to the previous ones a nd the
work piece surface is constantly eroded.

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Editura “Academica Br âncuși ” , Târgu Jiu, ISSN 1844 – 640X

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Fig. 7. Principle of operation of electrical erosion.
2.1. Spark gap
The voltage applied between the electrode and work piece and the discharge current
have a time sequence which is shown under the ill ustrations of the individual phases. Starting
from the left, the voltage builds up an electric field throughout the space between the
electrodes. As a result of the power of the field and the geometrical characteristics of the
surfaces, conductive particle s suspended in the fluid concentrate at the point where the field is
strongest. This results in a bridge being formed, as can be seen in the centre of the picture. At
the same time negatively charged particles are emitted from the negatively charged electr ode.
They collide with neutral particles in the space between the electrodes and are split. Thus
positively and negatively charged particles are formed. This process spreads at an explosive
rate and is known as impact ionization. This development is encour aged by bridges of
conductive particles.

Fig. 8. The evolution thermal phenomenon and graph electric voltage and the intensity .
Here again we see what in fact is invisible. The positively charged particles migrate to the
negative electrode, and t he negative particles go to positive. An electric current flows. This
current increases to a maximum, and the temperature and pressure increase further. The
bubble of vapors expands, as can be seen .

Fiabilitate si Durabilitate – Fiability & Durability No 2/ 2014
Editura “Academica Br âncuși ” , Târgu Jiu, ISSN 1844 – 640X

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Fig. 9. Electrical discharge process by electrical ero sion.
2.2. C onnection between the path of electrical power and heat.
The model shows how the supply of heat is reduced by a drop in the current. The
number of electrically charged particles declines rapidly, and the pressure collapses together
with t he discharge channel. The overheated molten metal evaporates explosively, taking
molten material with it. The vapour bubble then also collapses, and metal particles and
breakdown products from the working fluid remain as residue. These are mainly graphite and
gas.

Fig. 10. The graph particle electric and intensity trends and electrical voltage.
By means of the model we will now try to demonstrate the relationship between the
flow of current and heat. In a detail enlargement below we see the negativ e electrode surface,
and above it a part of the discharge channel

Fiabilitate si Durabilitate – Fiability & Durability No 2/ 2014
Editura “Academica Br âncuși ” , Târgu Jiu, ISSN 1844 – 640X

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Fig. 11. Spark erosion machining unit
Fig. 12. Schematic representation of the mechanics
of spark erosion.
3.RESEARCH OBJECTIVES.
We want to process turbine blade erosion by el ectric. For this we need to be selection
electrodes to obtain the desired roughness.
3.1.K ey factor s in the selection electrode
EDM (Electric Discharge Machining) has established itself as a precision technology
chosen more for what can be done than fo r what they can not do conventional cars. EDM
(Electric Discharge Machining) is a processing technology that enabled a multitude of new
applications, the importance of getting more water is put graphite electrode material used.
Although there are several methods to determine the correct material for an application, we
believe that there are five factors that can mean the difference between success and failure,
between profit and loss.

3.1.1.Metal removal rate – MRR
Metal removal rate is usually expressed in cubic millimeters per hour or cubic inches
per hour but can be expressed as realistic and $ / hour. Achieving an efficient MRR rate is not
just a matter of correct settings of the car. It involves also direct energy dissipated in the EDM
process. Graphi te is generally more efficient than metal electrodes but, however, metal
removal rates vary widely depending on the particular graphite. With the right material
chosen MRR rate can be maximized.
3.1.2.Wear resistance – WR
There are four types of wear: volu metric, from corner to end and side. Of the four, we
believe that corner wear is the most important since the contours of the final cut are
determined by the electrode to resist erosion of its corners and edges. This means that if a
eleectrod successfully resist erosion in its most vulnerable points, then overall wear will be
minimized and maximizes the life of the electrode. Electrode erosion can not be prevented,
but can be minimized by choosing the correct electrode / right combination of metal and
optim al settings.Electrode capacity to produce and maintain detail is directly related wear
resistance and processing capacity. Minimizing corner wear requires the choice of an
electrode material that combines high strength with high temperature resistance.

Fiabilitate si Durabilitate – Fiability & Durability No 2/ 2014
Editura “Academica Br âncuși ” , Târgu Jiu, ISSN 1844 – 640X

11 3.1.3.Surface finish – SF.
A good finish is achieved through a combination of correct electrode material, good condition
washing and supply the correct settings. High frequency, low power and orbiting produce the
best finish, as these conditions produce small er craters less defined metal. Final finish will be
a mirror image of the electrode surface, thus angstro -fine and ultrafine graphite with high
strength are the best choices for finishing electrodes.

3.1.4.Processability.
Any operator who knows machined g raphite graphite cuts very easily. Just because it is able
to process, does not mean that the material is the ideal choice for an electrode. It should be
strong to resist damage after handling and in the process of electro itself. Strength and small
size o f particuleelor are important because small tolerances can be achieved. The hardness of
the material is also a factor in graphite machinability, as tougher materials is much faster
chipping during the machining process.

3.1.5.The cost of the material.
Electrode material cost is generally only a small part of the total EDM. What is often
neglected but is that electrode material cost calculated out of the total application is devoid of
meaning. Fabricarre time, working time, labor, electrode wear – all these factors depend on
the electrode material more than any other factor. Thus, it is crucial to know the
characteristics of available materials for electrodes peerformanta because they affect metals
processing. Only with this information you can make an analy sis of the cost / performance to
determine the actual cost of EDM application.
4. RESEARCH METHODOLOGY AND DATA COLECTION.
4.1.Spezial solutions for processing the turbine blades.
We are specialists in development and construction of spezia l machines. You provide us
with your requirements – we develop solutions and produce the machine according to your
request and needs.

Fig. 13. The turbine blades processed by electrical erosion.

Fiabilitate si Durabilitate – Fiability & Durability No 2/ 2014
Editura “Academica Br âncuși ” , Târgu Jiu, ISSN 1844 – 640X

12 Work piece diameter 2,000 mm .Work pieceweight 1 T. Ele ctrode diameter 2.8 mm. Drilling
up to center axis with max. electrode length of 1,150 mm.

4.2. Novick technology orbit ii pro.
EDM machines with orbit – or vectorization – mostly used in a single electrode rough and
finish machining of workpiece s, eliminating the need for different electrodes. The result is a
significant reduction of time polishing and finishing as cavity walls kept longer smooth and
perpendicular to the workpiece, and a cost reduction recorded with electrode materials
through th e use of smaller electrodes in fewer. Technology orbit – which basically uses a head
electrode orbit to rotate around its center point to the desired radial cavity – allows an easier
and more precise control of the workpiece. Cavity size can be adjusted in dependently of the
electrode size and Novick Orbit II Pro technology lets you make 95% of all CNC machining
operations at a fraction of the cost of other CNC EDM machines. A normal burning a
conventional EDM machine / NC or CNC requires that you know the exact size of the cut
excess wash to have perfect conditions and requires the use of multiple electrodes – generally
one to two raw processing and finishing – and still does guarantees the elimination of taper.
The same burning carried out with a machine with orbital uses fewer electrodes – usually one
for raw processing and one for finishing. The machine offers the ability to perform
combustion Z axis and orbit to the desired size. Heun is able to drill around the corner. A
special process enables us, to machine the work piece at points difficult to access, with
bended and rotating electrodes.

Fig. 14. Graphic form of turbine blades using electrical erosion .
In the manufacture of turbine blades, coolant holes are required in extremely steep
entry and exit angles. Even though the material thickness is not known, the breakthrough of
the drilling without damage of the close rear panel has to be guaranteed.

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Fig. 15. The machine processing by electrical erosion.
Travel 2,100 x 900 mm. Electrode length up to 1,150 mm.Work piece weight up to 8
T.Heun is able to drill around the corner. A special process enables us, to machine the work
piece at points difficult to access, with bended and rotating electrodes.
4.3.Applications.
Winbro Group Technologies ha s developed a comprehensive range of application
solutions for aerospace and industrial cooling hole and form generation. These are often
tailored to fulfill the specific requirements of a particular engine design. The primary areas
where Winbro’s High Sp eed EDM, Laser and ECM technologies are applied include:Holes
for wall cooling and effusion cooled combustors.Film cooling holes in HP blades, vanes
segments.Laser drilling, cutting and ablation of various engine components.Shaped holes for
blades and van es.Cooling hole re -opening ECM forming of compressor blades. Creep -Feed
grinding of forms and features in blades, vanes segments.Additional applications and
machine systems are continually being developed to meet the specific needs of our customers,
ensur ing that we always provide the most appropriate solution to any individual application.

Fig. 16. Combustion area of a Gas Turbine Engine.

Fiabilitate si Durabilitate – Fiability & Durability No 2/ 2014
Editura “Academica Br âncuși ” , Târgu Jiu, ISSN 1844 – 640X

14 4.3.1. Small hole drilling edm is used in a variety of appications.
On wire -cut EDM machines, small hole drilling EDM is used to make a through hole
in a work piece in through which to thread the wire for the wire -cut EDM operation. A
separate EDM head specifically for small hole drilling is mounted on a wire -cut machine and
allows large hardened plates to h ave finished parts eroded from them as needed and without
pre-drilling. Small hole EDM is used to drill rows of holes into the leading and trailing edges
of turbine blades used i n jet engines . Gas flow through these small holes allows the engines to
use higher temperatures than otherwise possible. The high -temperature, very hard, single
crystal alloys employed in these blades makes conventional machining of these holes with
high aspect ratio extremely difficult, if not impossible. Small hole EDM is also used to create
microscopic orifices for fuel system components, spinnerets for synthetic fibers such as rayon ,
and other applications. There are also stand -alone small hole drilling EDM machines with an
x–y axis also known as a super drill or hole popper that can machine blind or through holes.
EDM drills bore holes with a long brass or copper tube electrode that rotates in a chuck with a
constant flow of distilled or deionized water flowing through the electrode as a flushing agent
and dielectric. The electrode tubes operate like the wire in wire -cut EDM machines, having a
spark gap and wear rate. Some small -hole drilling EDMs are able to drill through 100 mm of
soft or through hardened steel in less than 10 seconds, averaging 50% to 80% wear rate.
Holes of 0.3 mm to 6.1 mm can be achieved in this drilling operation. Brass electrodes are
easier to machine but are not recommended for wire -cut operations due to eroded brass
particles causing "brass on brass" wire breakage, therefore copper is recommended.

Fig. 17 . A turbine blade with internal cooling as applied in the high -pressure turbine .

Fig. 18. Small hole drilling EDM machines .

Fiabilitate si Durabilitate – Fiability & Durability No 2/ 2014
Editura “Academica Br âncuși ” , Târgu Jiu, ISSN 1844 – 640X

15 4.3.2.T urbine blades high pressure.
Winbro manufactures machine systems which are used to create the miniature holes
required to cool aero and industrial gas turbine high pressure blades. These holes are critical
in allowing internal airflow to cool parts and prevent overheating during engine operation.
Effective cooling improves component efficiency leading to reduced fuel consumption and
NOx emissions on today’s generation of lightweight, low noise, jet engines.Cooling holes
shield components from temperatures that are often higher than their melting point, making
their precise design and manufactur e a critical feature of the engine. Components are often
cast from high nickel and high cobalt alloys to enhance performance and longevity.Winbro
uses different processes to produce cooling holes – EDM, Laser Drilling, Laser Ablation or a
combination of th ese. The choice of these technologies can be influenced by the particular
coating applied to the part (Ceramic or Metallic) , metallurgy / productivity requirements or
component / feature access. Winbro Group Technologies has become recognised as a world
leader in the development and implementation of these technologies for the production of
cooling holes.

Fig. 20. Industrial gas turbine blade with
(thermal barrier coating).

Fig. 21. Typical HP Turbine Blade.
Fig. 19. High Speed EDM single point drilling of a HP
Aero Turbine Blade.

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Fig. 22 . Erosion Machine QXD250 -Vollmer Technologies India.

Now with the addition of the FGC 2 creep -feed grinding machine manufactured at
Winbro we offer multi axis grinding of features such as fir -tree r oot forms.
Vollmer Werke, based at Biberach, Riss, Germany, are known worldwide as an
eminent Manufacturer of an extensive range of machines for sharpening of Band, TCT HSS
blades Erosion machines for rotary diamond tools. Accredited as a privately held family
owned company, we have carved ourselves a position amidst the acknowledged
manufacturers, suppliers and exporters of an exhaustive collection of Saw Sharpening
Machines for Band Saws, Circular Saws (TCT HSS) Erosion Machines for Rotary Diamond
Tools. These machines are valued by our clients for their superior technology, durability,
reliability and sturdy structure. With an experience of over 103 years, we have earned the
respect and sincerity of our customers world -wide. We have employed a team of highly
qualified professionals that works relentlessly to cater to the growing demands of our clients.
Products we offer are manufactured using superior quality raw materials that are procured
from the most trusted vendors of the industry. Our team of qua lity controllers keeps a
stringent check on each step of the entire production processes in order to delivery a top
quality product to our customers.

Fiabilitate si Durabilitate – Fiability & Durability No 2/ 2014
Editura “Academica Br âncuși ” , Târgu Jiu, ISSN 1844 – 640X

17 4.THE INFORMATICS PROGRAMS ANSSYS PROCESSING
BYELECTRICAL EROSION OF TURBINE BLADES.

Fig. 23 . Informatics programs applied to turbine
blades. Fig. 24. Informatics programs applied to turbine
blades.

Fig. 25. Informatics programs applied to turbine
blades.
Fig. 26. Informatics programs applied to turbine
blades.

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Fig. 27. Informatics programs applied to turbine
blades Fig. 28. Informatics programs applied to turbine
blades.

Fig.29. Informatics programs applied to turbine
blades Fig. 30. Informatics programs applied to turbine
blades.

.

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Fig. 31. Infor matics programs applied to turbine
blades. Fig. 32. Informatics programs applied to turbine
blades.

Fig. 33. Informatics programs applied to turbine
blades. Fig. 34. Informatics programs applied to turbine
blades.

Fig. 35. Informatics pr ograms applied to turbine
blades.
Fig. 36. Informatics programs applied to turbine
blades.

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Fig. 37. Informatics programs applied to turbine
blades. Fig. 38 . Informatics programs applied to turbine
blades.

Fig. 39. Informatics programs ap plied to turbine
blades. Fig. 41. Informatics programs applied to turbine
blades.

Fig. 42. Informatics programs applied to turbine
blades.
Fig. 43. Informatics programs applied to turbine
blades.

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Editura “Academica Br âncuși ” , Târgu Jiu, ISSN 1844 – 640X

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Fig. 44. Informatics programs applied to turbine
blades.
Fig. 45. Informatics programs applied to turbine
blades.

Fig. 46. Informatics programs applied to turbine
blades.
Fig. 47. Informatics programs applied to turbine
blades.

5. A CASE STUDY.

The electrical erosion processing p arameters turbines, for the case study, we used the
following parameters of electrical erosion values in the chart below.
Ra -The surface roughness of turbine blade.
Uz -The tool electrode the wear.
Tp – The pause time between two impulses.
Ti – The imp ulse time.
Qp –. The productivity of realized.
Or You realized 10 experiments processing electrical erosion of turbine blades values below.

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Fig. 48. Table containing the values parameters of electrical erosion.

Fig. 49. Table containing the values pa rameters of electrical erosion.

Fig. 50 . The form 2D graphics parameters electrical erosion.

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Fig. 51. The reporting parameters electrical erosion to roughness.

Fig. 52. The connection between electrical erosion parameters .

Fig. 53. The shape 2D the electrical erosion parameters and their values.

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Fig. 54. The form 2D graphics parameters electrical erosion.

Fig. 55. The shape 2D the electrical erosion parameters and their values.

Fig. 56. Table containing the values parameters of el ectrical erosion.

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Fig. 57. The form 2D graphics parameters electrical erosion.

Fig. 58. The shape 2D the electrical erosion parameters and their values.

Fig. 59. Table containing the values parameters of electrical erosion.

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Fig. 60 . The r eporting parameters electrical erosion to roughness and wear.

Fig. 61. Table containing the values parameters of electrical erosion.

Fig. 62. The shape 2D the electrical erosion parameters and their values.

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Fig. 63. Table containing the values parameters of electrical erosion.

Fig. 64. The connection between electrical erosion parameters.

Fig. 65. Table containing the values parameters of electrical erosion.

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Fig. 66 . The shape 3D the electrical erosion parameters and their values.

Fig. 67. The form 2D graphics parameters electrical erosion.

Fig. 68. Table containing the values parameters of electrical erosion.

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29

Fig. 69. The shape 2D the electrical erosion parameters and their values.

Fig. 70. Table containing the va lues parameters of electrical erosion.

Fig. 71. Representation of process parameters of electrical erosion.

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30

Fig. 72 .Representation of process parameters of electrical erosion.

Fig. 73 . The right equation parameters erosion electrical .

Fig. 74. The right equation parameters erosion electrical .

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Editura “Academica Br âncuși ” , Târgu Jiu, ISSN 1844 – 640X

31

Fig. 75. The right equation parameters erosion electrical .

Fig. 76. Form 2D graphics and equations of lines.

Fig. 77. The form 2D graphics parameters electrical erosion.

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Editura “Academica Br âncuși ” , Târgu Jiu, ISSN 1844 – 640X

32 6.RE SULTS AND DISCUSSIONS.

The electric erosion machining of turbine blades note that the results obtained by the
equations s raight lines and the graphics in the form of balls the results are the same.

Fig. 78. The right equation parameters erosi on electrical .

FIG. 79 . The right equation parameters erosion electrical .

Fig. 80. Form 2D graphics and equations of lines.

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33

Fig. 81. Form 2D graphics and equations of lines.
When productivity is Qp = 19 and the momentum is Ti = 3 results in su rface
roughness Ra = 2,8. And when productivity is Qp = 78 and momentum is time Ti = 25 have
a roughness of Ra = 4,85. Maximum value of surface roughness is when Ti = 400 and Qp =
59 and result Ra = 7.85

Fig. 82. The reporting of parameters electr ical erosion roughness .

7.CONCLUSIONS.
Orbital (radial movement) or trace (angular movement) to the electrode ensures better
wash, removes the wall cavity conicity and allows you to control the size you Want. During
electro -erosion, the material is remov ed by electrical discharge, leftover (Particles and
electrode -wool molten Board) traveling Towards the upper edge of the wall of the secondary
cavity Creating That produces a conical effect, known as the bell -mouth, as you leave the
cavity. Once Reached th e desired Z -depth, movement of the blind or tracing allows you to
remove the secondary discharge Produced conicity. Spindle taper Will Be removed Using the
same settings used in the processing of the raw. Once the spindle taper is removed, dazzling
Until t he desired finish by decreasing the power settings. The movement of the blind or
tracing also creates a vacuum: pushing the dielectric liquid cleaner into the hole and drag –
forcing molten out of Spain, The which provides a much better finish. The movement of the
blind and tracing is programmable on each axle U and V or V and W or U and W.

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34 The biggest advantage of EDM technology orbit from Novick is the ability to make
electrodes uniform size. Normally, an EDM machine without orbital positions, start with a
much smaller electrode for raw processing, then choose a larger electrode to finish, because
we have the ability to rotate. With the Pro -II orbit can make an electrode -sized – no need to
get the exact dimensions immediately if you have a wall orbital cle aner and straighter, a more
efficient and cheaper.

8.REFERENCES.

[1] Ailincai, G.: Studiul metalelor ,Institutul Politehnic Iasi, 1978.
[2] Balc, N.: Tehnologii neconventionale, Editura Dacia Publishing House, Cluj –
Npoca, 2001.
[3] Bolundut, L.I.: Materiale si tehnologii neconventionale, Editura Tehnica -Info,
Chisinau, 2012.
[4] Buzdugan, Gh., ș.a. – Vibrații mecanice, Editura Didactică și Pedagogică,
București, 1979.
[5] Constantinescu, V., ș.a. – Lagăre cu alunecare, Editura Tehnică, București 1980.
[6] Colan, H.: Studiul metalelor, Editura Didactica si Pedagogica , Bucuresti, 1983.
[7] Domsa, A.: Materiale metalice in constructia de masini si instalatii, Editura
Dacia, 1981.
[8] Gafițanu, M. ș.a. – Organe de mașini, vol. 2. Editura Tehnică, București, 2002.
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“DanubiaAdria”, Bertinoro, Italia, 181 -183.
[10] Nichici, A.: Prelucrarea prin eroziune electrica in constructia de masini, Editura
Facla, Timisoara, 1983.
[11] Olaru, D.N. – Tribologie. Elemente de bază asupra frecării, uzării și ungerii,
Litografia Institutului Politehnic „Gheorghe Asachi”, Iași, 1995.
[12] Popa,M.S.:Masini, tehnologii neconventionale si de mecanica fina -Editie Bilingva,
Romana -Germana, Editura U.T.PRESS, Cluj -Napoca, 2003.
[13] Popa, M.S.: Tehnologii si masini neconventionale, pentru mecanica fina si
microtehnica, Editura U.T.PRESS, Cluj -Napoca, 2005.
[14] Popa, M.S.:Tehnologii inovative si procese de productie, Editura U.T.PRESS, Cluj –
Napoca,2009.
[15] Rădulescu, Gh., Ilea, M. – Fizico -chimia și tehnologia uleiurilor lubrifiante, Editura
Tehnică, București, 1982,
[16] Sofroni, L.: Fonta cu grafit nodular,Editura Tehnica, Bucuresti, 1978.
[17] Trusculescu, M.: Studiul metalelor, Editura Didactica si Pedagogica ,Bucuresti
,,1978.