Analysis of the relationship between electrolyte characteristics and electrochemical machinability in PECM on invar (Fe-Ni)fine sheet

Abstract

Pulsed electrochemical machining (PECM) has been conducted for invar (Fe-Ni) fine sheet consisting of 64 % Fe ions and 36 % Ni ions. Solutions of sodium chloride (NaCl), acetic acid (CH 3 COOH), sodium nitrate (NaNO 3 ), and sodium nitrite (NaNO 2 ) mixed with sodium tartrate (C 4 H 4 Na 2 O 6 ) were used as an electrolyte. First, the electrical conductivities of all electrolytes have been measured. As the concentration of each electrolyte increased, the electrical conductivities of electrolytes increased except for the acetic acid. The electrochemical machinability has been investigated using four types of electrolytes. The results of PECM show that the electrolyte which has the high electrical conductivity value leads to the low electrochemical machinability. The pulse waves which indicate the electrical characteristics during the PECM has been observed and it is confirmed that the passivating oxide film occur in PECM. To compare the capability of changing in transpassive state, the anode surface has been investigated. This study presents the relationship between electrical conductivity and electrical machinability. Moreover, the capacity of changing in transpassive state has been investigated as compared with four types of electrolytes. This study shows the possibility of applying invar fine sheet in PECM and contributes to determining the electrolyte for the process.

Analysis of Mechanisms Affecting the Tool in Pulsed Electrochemical Machining

“…The conductivity is correlated to the concentration of the electrolyte, which by increasing conductivity, concentration increases. 44…”

Electrolytic-dielectrics: A route to zero recast electrical discharge machining

“…The nitrite ion from NaNO2 is well known to be a passivating corrosion inhibitor which easily forms an effective oxide film on a surface [27,35]. Compared to NaNO3 it can be assumed that the formed oxide layer is more stable thus reducing the rate of electrochemical dissolution resulting in a surface which is more uniformly machined with reduced pitting.…”

Performance Analysis of Electrochemical Micro Machining of Titanium (Ti-6Al-4V) Alloy under Different Electrolytes Concentrations

“…The size of the crater is established by the current density and the time duration (pulse-on time + pulse-off time ratio) of applied electrical energy [31]. The NaCl + NaNO 3 has higher electrical conductivity nature to produce a larger peak and valley surface and it has achieved higher circularity [32,33]. It has been understood that the higher pulse duration and higher current density can generate a better machined workpiece surface.…”