A Study on Electrochemical Machining Performance Analysis of Shape Memory Alloy with Electrolyte and Electrode
Nitinol shape memory alloy (SMA) is used in various industries such as medicine and aerospace. Micro-scale and
complex shapes of SMA are often needed. Electrochemical machining is a non-contact method that has advantages regarding
defects like thermal strain and micro burrs compared to other non-conventional machining methods, such as laser machining,
electro-discharge machining, and etching. An insulated electrode is required for precise electrochemical machining. In this
study, current density analysis was performed to determine the current density for three types of electrodes. The isolated
electrodes had high current density in the same conditions. The workpiece was nitinol SMA. Square shapes were fabricated in
electrochemical machining using a square electrode, a square electrode insulated on only the sides, and a square electrode
insulated on the sides and center. The influence of the insulation layer on the applied current has been investigated. It is
possible to obtain precise square shapes on SMA if the insulation layer controls the unnecessary current between the electrode
and workpiece, which would be helpful in the medical and aerospace industries. The square electrode without an insulation
layer creates inexact square shapes due to the unnecessary current. The side-insulated electrode creates precise square shapes.
The most precise square shapes were found when the square electrode insulated on the sides and center was applied because
the insulation layer concentrates the unnecessary current on the machining area and improves the removal rate.
Index Terms - Shape memory alloy (SMA), Micro machining shape, General electrode, Fillet electrode