Review of the Machining Difficulties of Nickel-Titanium Based Shape Memory Alloys

The purpose of this study is to identify machining difficulties of nickel-titanium based shape memory alloys. Nickel-titanium (Nitinol) is one the widely used shape memory material which is applied in many products in the aerospace, medical, and biomedical fields. NiTi alloy cannot be machined easily because of high tool wear, high cutting force, huge hardness and surface defects are made many problems into their machining. Investigation in micron precision shows plenty surface defects in machining process, something like debris of microchips, feed marks, tearing surface, deformed grains, material cracking and chip layer formation which consists the main problem in the machining of shape memory alloys. Moreover, these defects can be reduced or eliminated by changing the cutting parameters such as: feed rate, cutting speed and cutting depth so that, machining of nickel-titanium alloys would be improved.