Accession Number:

ADA031857

Title:

Electromechanical Machining.

Descriptive Note:

Final technical rept.,

Corporate Author:

MARTIN MARIETTA LABS BALTIMORE MD

Personal Author(s):

Report Date:

1976-01-01

Pagination or Media Count:

33.0

Abstract:

The purpose of this work was to adapt the new process of electromechanical machining EMM, in which metal is cut by direct contact of the tool with an electrochemically polarized workpiece, to turning and drilling. This investigation, which followed experiments in shaping, was focused on the turning and drilling of commercial alloys, particularly weapons materials such as 4140 steel and CG27 alloy, and the design and construction of a prototype EMM control console. Electromechanical drilling of nickel-base alloys is most effective at potentials in the transpassive range of the polarization diagram for the work-piece in an aqueous Na2SO4 electrolyte. On the other hand, the penetration rate, tool life, cutting forces and hole surface finish experienced when drilling 4140 steel are far superior at active rather than passive, or neutral, potentials. These observations indicate the importance of proper selection of electrolytes and cutting potentials for each alloy of interest. Investigations showed that, at handbook recommendations for cutting speeds and feeds, electromechanical turning of 4140 steel was superior, in terms of cutting forces, to conventional turning. A portable, EMM control console, consisting of a 10-amp potentiostat, power supply, and related control for thermoelectric currents was assembled. Author

Subject Categories:

  • Fabrication Metallurgy
  • Machinery and Tools

Distribution Statement:

APPROVED FOR PUBLIC RELEASE