Experimental investigations of suitability of electrolyte solutions for anodic dissolution of nickel aluminum bronze

Abstract

Micro electrochemical machining (ECMM) is an attractive area of research due to the fact that this process does not produce any tool wear and any defective layer after anodic dissolution and it gives better surface finishing on different micro applications including surgical tool, aerospace, stress-free drilled holes in automotive manufacturing with complex shapes, etc. It is a challenging task for machining nickel aluminum bronze (NAB) alloy due to its excellent mechanical, chemical, and other unique properties. This paper describes relevant problems and solutions for the circular micro-hole machining in NAB alloy (1 mm thick plate) using a tungsten carbide tool of diameter 0.4 mm and sodium chloride and sodium nitrate as an electrolyte solutions. The influence of process parameters like applied voltage, concentration of the electrolyte, and duty factor on radial overcut and surface roughness has been studied. The experimental results show that the good surface finish and least radial overcut achieved from sodium nitrate (NaNO3) electrolyte when compared to that of sodium chloride (NaCl) electrolyte. The machined hole diameter was measured by using a metallurgical microscope.