US3355369A - Process using a fluoride electrolyte for the electrolytic and electrochemical working of metals - Google Patents

Process using a fluoride electrolyte for the electrolytic and electrochemical working of metals Download PDF

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Publication number
US3355369A
US3355369A US329021A US32902163A US3355369A US 3355369 A US3355369 A US 3355369A US 329021 A US329021 A US 329021A US 32902163 A US32902163 A US 32902163A US 3355369 A US3355369 A US 3355369A
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United States
Prior art keywords
electrolyte
electrolytic
workpiece
grinding
working
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Expired - Lifetime
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US329021A
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English (en)
Inventor
Chaperon Remy
Ullmann Werner
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Agie Charmilles SA
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Agie Charmilles SA
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23H—WORKING OF METAL BY THE ACTION OF A HIGH CONCENTRATION OF ELECTRIC CURRENT ON A WORKPIECE USING AN ELECTRODE WHICH TAKES THE PLACE OF A TOOL; SUCH WORKING COMBINED WITH OTHER FORMS OF WORKING OF METAL
    • B23H3/00—Electrochemical machining, i.e. removing metal by passing current between an electrode and a workpiece in the presence of an electrolyte
    • B23H3/08—Working media

Definitions

  • the present invention relates to an improved process and electrolyte for the electrolytic grinding of metals or .for other electrolytic and electro-chemical metal working processes,-for example electrolytic sinking.
  • the process for electrolytic grinding is based upon the feature that a strong direct current is simultaneously delivered during grinding through the arrangement including grinding disk, ion conducting cooling fluid and workpiece.
  • the electron conducting grinding wheelor disk generally a metal-bound diamond disk, provides the negative electrode in the arrangement, namely, the cathode.
  • the workpiece to be processed is then the positive electrode, namely, the anode.
  • the electrolyte which simultaneously undertakes the function of cooling, is generaly an aqueous salt solution. Since these electrolytes come into contact with portions of the grinding machine important for the operation thereof, such must be as little corrosive as possible, which then considerably limits the number of useable salts.
  • the electrolyte under the above-described electrical .conditions' possesses a the metal to be worked, there then results a new'typeof metal working or shaping or duplication, which has been termed in the art as sinking;
  • the electrode serving for applied to the workpiece to be I treated while maintaining a small work gap.
  • the electroworking or sinking is lyte isintroduced in suitable manner, for example through the electrode itself into the work gap.
  • the work gap- is held constant by means of a suitable feed-control mechanism.
  • the metallic displacement or removal is only conditioned upon the current.
  • the width of the grinding gap is given by the diamond grains of the grinding disk and by the externally effective contact pressure of the workpiece.
  • Insulating of the insert and plastic edges at the grinding disk should suppress the formation of sparks which then appear when the workpiece is applied to the disk or removed therefrom, or when the portion of the workpiece to be ground which has left the grinding surface is again brought into contact.
  • a considerable advantage of the electrolytic working process resides in the feature that, the removal of material takes place without appreciable heating, which obviates thermal damage to the tool.
  • the present invention contemplates as one of its primary objects the provision of an improved process and electrolyte for the electrolytic working of metals in an eificient and reliable .manner within relatively broad ranges of contact pressure and voltage.
  • *IAnother important object of this invention is to provide. improved process and electrolyte for electrolytic metal Working, resulting in excellent surface qualities at the workpiece as well as improved metal removal capacity.
  • Yet another noteworthy object of the present invention is directed to the provision of an improved electrolyte for electrolytic metal working which is characterized by the feature that its essential component contains water soluble fluorides or fluoride compounds.
  • Still a further important object of the present invention is the 'PI'OYlSlOI J of an improved process and electrolyte-forelectrolytic metal working or the like ensuring for less wear at the grinding or work tool.
  • a furtherobject of the invention contemplates the protection of 'the surfaces of the workpiece which are not to be worked, by applying thereto a coating composition containing an electron conductive pigment and a binding agent of an organic or inorganic nature.
  • FIG. 1 An illustration of the state of the art
  • FIG- URE 4 graphically illustrates results obtained by employing the inventive process and'cleCtf-olyte.
  • FIGURE 2 there is shown in similar manner the operation of a commercial electrolyte on the basis of sodium nitrite-sodium nitrate with organic additives.
  • two hard metal samples of;:type, P40 and, P10 these materials being well known -cemented carbides. From this figure is also discernable the fact that a good operating region only lies in a very narrow voltage range.
  • FIGURE 3 contains the same data for a commercial electrolyte available, under a particular trademark which is on the basis, of sodium nitrite-sodium dihydrogenphosphate sodium tetraborate. Out of this figure there is likewise discernible that for the most different work materials the useable range is present, only verynarrow im s.
  • Electrolytes which contain components which advance the chemical corrosion of the. passive layer, e.g. formation of complexing agents,
  • Electrolytes which contain components which are incorporated in the passive: or cover layers and; influence t e. characte i t cs the a s ch that th y a be easi r m ed or c ried a m c an c l (f); Electrolytes which contain components which. are incorporated in the double layer, cover layer or passive lay r. nd w c in e th an o of the at o s o anions or both through this layer.
  • Electrolytes according to items (c): to (g) can be effective even if they have buffering properties or oxidative effects. 4
  • the measures set forth in items (d), (e), (f) and (g) are particularly suitable for electrolytic grinding.
  • the measures of items (a) to (m) are of particular importance.
  • the invention is concerned with the problem of fulfilling these measures.
  • the electrolyte or electrolytic solution in its essential component contains water soluble fluorides or fluoro or fluoride compounds. It has been found that these solutions, in particular potassium fluoride in medium and high concentrations, work absolutely in faultless manner in very broad ranges of the contact pressure (kp./cm. as well as the voltage. In addition to excellent surface quality there result removal capacity or efliciencies which have not even been closely approached by any of the previous known electrolytes.
  • FIG. 4 illustrates the behavior of a potassium fluoride electrolyte with 15% potassium fluoride in accordance with the invention.
  • V voltage
  • mm. /cm. /min. material removal capacity
  • the individual curves were plotted with diflerent contact pressures (kp./cm. as indicated thereat.
  • kp./cm. diflerent contact pressures
  • FIGURE 4 is only a small portion of the possible working range of the inventive electrolyte.
  • Such larger trouble-free zone is clearly perceivable by comparing FIGURES 1, 2 and 3 which depict the previous known electrolytes, with FIGURE 4 representing the electrolyte according to the invention.
  • a further advantage of the electrolyte according to the present invention resides in the fact that, the wear of the grinding disks is smaller. For this reason there can be advantageously selected a material for the grinding disks which no longer corresponds to a diamond. According to the invention 6 it has become possible to submit grinding wheels or disks to shaping operations.
  • Concentrated to saturated fluoride-containing solutions are particularly well suited also for sinking.
  • hard metals such as cemented carbides.
  • acidic, neutral or alkaline solutions According to the properties of the materials to be Worked there are employed acidic, neutral or alkaline solutions. It has been found desirable when potassium fluoride is employed in the electrolyte solution that it be present in a concentration of at least 4%.
  • the electrolyte in addition to a water soluble fluoride, also contains other salts, such as nitrites, nitrates, phosphates, carbonates, sulphates or .saltsof organic acids and bases, whereby the mentioned .saltsare combined with fluorides.
  • the electrolyte possesses a pronounced solvating capacity for the passave layers arising at the anode and which mechanically are very wear'resistant, as. well as for the carbides contained in the hard metals.
  • the electrolyte contain ions, in particular fluoro-ions, which are embedded in an anodic produced passive or cover layers and influence such layers in a manner favorable for the execution of the process.
  • a process for the electrolytic working of metallic workpieces comprising the steps of providing a workpiece formed of a material selected from the group consisting of steel and cemented carbides as one electrode and electrode, filling the space between said electrodes with an electrolyte and removing material from said workpiece by passing a direct current between said electrodes and through said electrolyte, said electrolyte consisting essentially of an aqueous solution of a Water soluble fluoride salt having a pH ranging from a generally neutral solution to a mildly alkaline solution.
  • Process for the electrolytic working of metallic workpieces according to claim 1 including the step of driving the other electrode.
  • Process for the electrolytic working of metallic workpieces according to claim 1 including the step of covering the surfaces of the workpiece which are not to be worked with an electron conductive layer in order to limit material removal.
  • Process for the electrolytic working of metallic workpieces according to claim 1 including the step of covering the edges and surfaces oi the metallic workpiece which are not to be subjected to the working process with an ele'ctron conductive coating composition in order to protect such edges-and surfaces.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
  • Electrolytic Production Of Metals (AREA)
US329021A 1962-12-11 1963-12-09 Process using a fluoride electrolyte for the electrolytic and electrochemical working of metals Expired - Lifetime US3355369A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CH1450062A CH465730A (de) 1962-12-11 1962-12-11 Elektrolyt zur formgebenden Bearbeitung ausgewählter Oberflächenteile eines metallischen Werkstückes

Publications (1)

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US3355369A true US3355369A (en) 1967-11-28

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US329021A Expired - Lifetime US3355369A (en) 1962-12-11 1963-12-09 Process using a fluoride electrolyte for the electrolytic and electrochemical working of metals

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US (1) US3355369A (de)
AT (2) AT248568B (de)
CH (1) CH465730A (de)
DE (1) DE1440953A1 (de)
GB (1) GB1070912A (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3429791A (en) * 1965-10-23 1969-02-25 Gen Motors Corp Electrochemical machining ferrous metals using a film forming electrolyte including fluoride salts
US4163701A (en) * 1977-02-24 1979-08-07 Centre Technique Des Industries Mecaniques Method of electrochemical machining of polyphase alloys
US4193853A (en) * 1979-05-15 1980-03-18 The United States Of America As Represented By The United States Department Of Energy Decontaminating metal surfaces

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114478305B (zh) * 2022-03-17 2024-04-02 武汉船用电力推进装置研究所（中国船舶重工集团公司第七一二研究所） 一种有机电极材料及其制备方法

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2469689A (en) * 1944-03-25 1949-05-10 Eastman Kodak Co Method of making apertured metal sheets
US2506582A (en) * 1945-06-20 1950-05-09 Mateosian Edward Der Electrolytic polishing of metals
US2558504A (en) * 1946-03-12 1951-06-26 Aller Claes Borge Method of producing a printing form having a bimetallic surface
US2766199A (en) * 1951-07-04 1956-10-09 Magnesium Elektron Ltd Cleaning of magnesium base alloy castings
US2805197A (en) * 1955-11-07 1957-09-03 Norton Co Methods of electrolytic grinding and eroding
US3058895A (en) * 1958-11-10 1962-10-16 Anocut Eng Co Electrolytic shaping
US3061494A (en) * 1959-10-05 1962-10-30 Boeing Co Process of chemical milling and acid aqueous bath used therefor
US3088889A (en) * 1959-06-08 1963-05-07 Gen Motors Corp Electrolytic machining of metal surfaces
US3130138A (en) * 1959-11-27 1964-04-21 Battelle Development Corp Electrolytic cutting

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2469689A (en) * 1944-03-25 1949-05-10 Eastman Kodak Co Method of making apertured metal sheets
US2506582A (en) * 1945-06-20 1950-05-09 Mateosian Edward Der Electrolytic polishing of metals
US2558504A (en) * 1946-03-12 1951-06-26 Aller Claes Borge Method of producing a printing form having a bimetallic surface
US2766199A (en) * 1951-07-04 1956-10-09 Magnesium Elektron Ltd Cleaning of magnesium base alloy castings
US2805197A (en) * 1955-11-07 1957-09-03 Norton Co Methods of electrolytic grinding and eroding
US3058895A (en) * 1958-11-10 1962-10-16 Anocut Eng Co Electrolytic shaping
US3088889A (en) * 1959-06-08 1963-05-07 Gen Motors Corp Electrolytic machining of metal surfaces
US3061494A (en) * 1959-10-05 1962-10-30 Boeing Co Process of chemical milling and acid aqueous bath used therefor
US3130138A (en) * 1959-11-27 1964-04-21 Battelle Development Corp Electrolytic cutting

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3429791A (en) * 1965-10-23 1969-02-25 Gen Motors Corp Electrochemical machining ferrous metals using a film forming electrolyte including fluoride salts
US4163701A (en) * 1977-02-24 1979-08-07 Centre Technique Des Industries Mecaniques Method of electrochemical machining of polyphase alloys
US4193853A (en) * 1979-05-15 1980-03-18 The United States Of America As Represented By The United States Department Of Energy Decontaminating metal surfaces

Also Published As

Publication number Publication date
CH465730A (de) 1968-11-30
GB1070912A (en) 1967-06-07
DE1440953A1 (de) 1969-03-27
AT248568B (de) 1966-08-10
AT247479B (de) 1966-06-10

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