This article describes the applications, process capabilities, and limitations and advantages of electrostream and capillary drilling. It describes equipment and. NPTEL provides E-learning through online Web and Video courses various streams. Book Source: Digital Library of India Item : Sridhar ioned.
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At higher voltages the hole drilled in I IS. Values of parameters for different levels 28 References 1. The complete conversion table is tabulated in Table 2. It is evident from the fig 1.
The reason for an increase in diameter of the hole at the top surface is partly attributed to the stray current effect and partly due to the fact that this portion of the workpiece is subjected to electro-chemical dissolution throughout the period of drilling.
It is drawn from coming glass, which possesses good strength and is inert to chemicals. Chapman and Hail London, Initially the pump is switched on drillint electrolyte supply is ensured. Namdev for their consistent efforts in making the experimental set up.
Electrostream Drilling Of High Speed Steel
Insertion of a nozzle with a formed tip permits right angled drilling deep inside the prior hole Fig 1. So the machined hole profile is captured using the shadow graph at 20X magnification. H 2 S 04can be used to machine carbon steel, stainless steel, udimet, rene.
Partial passivation caused by the loiiuaiioii of thick tdack film at higher electrolyte concentrations. So the system is made leak proof. The chamber is provided with 12 Drulling D. Work piece can be held in the work vice with the help of a tightening screw made of perspex. Asymmetry is observed in opposite faces of hole profiles, this may be due location of hole center not driling along the parting line; Performed experiments demonstrated feasibility of the use of HCl as elec- trolyte in place of normally used NaCl.
HSS is used as cutting tool material for turning, milling, shapingplaningbroaching etc.
Schematic showing the deepest depth profile 24 2. Ltd Piping The pipes carrying the electrolyte must be acid resistant. Let y be the estimated response at a point on the fitted second order surface as given by equation given below.
Electrostream and Capillary Drilling | Machining | Books Gateway | ASM International
Electrstream increase is attributed to stray current effect i. Additionally, there is some obstruction to the coolant flow since the chip direction is opposite to the direction of drill penetration.
With ESD holes as small as 0. Chryssoluris and Wollowitz  developed an electro chemi- cal hole making technique eldctrostream uses uninsulated tools and passivating XaClOz electrolytes. The figure shows that the machined holes have conical profile i.
During the course of study an attempt has been made to evaluate the effect of process parameters i. Additional head due to gravity is obtained by plac- ing the reservoir at an elevation. One such problem is drilling small deep holes in the super al- loys. They reported that the aspect ratio depends on stand off distance and machining time. The same procedure is adopted for measuring the diameter of the machined hole. Electrolyte supplying system, 4.
The ESD machine has been designed keeping in view of the fundamental mechanism of the process. The design of experiment is the procedure of selecting the number of trials and conditions for running them, essential and sufficient for solving a prob- lem that has been set with the required precision.
Basic components of an electrolyte supply system are as follows: But drilling deep, small holes with salt electrolytes produces a large volume of sludge, which tends to clog the flow of electrolyte.
So instead of normal injection needles, using Titanium, Gold, or Platinum tubing may be effective. Cost comparison b Drilling capabilities compared Figure 1. With the above conversion the experiments are conducted in the random order according to the plan given in Table 2. This aspect led to the development of high strength and temperature resistant, hard and brittle materials, whose machining posed serious problems to the manufacturing industries.
ECM is considered as an efficient process for machining complicated shapes in any hard and electrically conductive material. This aspect led to the development of specialized EC drilling techniques, the prominent micro drilling techniques being shaped tube electrolytic machining STEMand electro stream drilling ESD.
Since, increase in voltage increases the machining currentthis increase in current causes an increase in machined mass. An im- provement in process reliability is realized as tool insulation would be eliminated. Typical minimum diameter can be achieved by LBM. Contact between the tool and the side wail.
The pipes used in the flow path are of 0.
Work table Both are made up of perspex, as perspex is acid resistant material and it possess good electrical insulating properties. This aspect helps in easy ad- justments, and improves flexibility of the system. Sridhar Sastry Abstract Advances in the field of aerospace, gas turbine, nuclear technologies have pro- duced the need to machine the super eleftrostream and refractory metals. The complex designs associated with the drillinv engine hardware have posed 1 machining problems which are beyond the capabilities of conventional machin- ing processes.
The general principle of material removal by anodic dissolution was one of the discoveries of Michael Faraday. The starting distance between the wire end and work is always kept constant by adjusting the nozzle prior to every experiment.