Features of face milling of Ni-Ti alloys with shape memory effect

Abstract

The paper reviews current research on the processing of Ni-Ti alloys (nitinols). These functional materials undergo martensitic transformations that determine their specific physical and mechanical properties (shape memory effect, superelasticity, high damping capacity, etc.). The physical and thermomechanical properties of Ni-Ti alloys with shape memory effect are described, as well as the phenomena that accompany the machining process and are the cause of the low machinability of these materials. An overview of suitable tool materials, cutting modes, and machining conditions proposed by modern practitioners and researchers is given. The results of known works on the determination of cutting forces, temperatures, tool life, roughness and microhardness of machined surfaces, depth of hardened layer and residual stresses are analyzed. The results of experimental studies of face milling process of nitinols under the conditions of dry, cryogenic machining and machining with minimum quantity lubrication are discussed. It was found that the processes of face milling of Ni-Ti alloys with shape memory effect of different brands have not yet been extensively and widely researched to determine the conditions for guaranteed effective machining. The need for further scientific research on promising ways to increase the efficiency of face milling of nitinols while ensuring high quality of the surface layer of the products is substantiated.

Keywords

• nitinol
• phase transition
• austenite
• martensite
• cutting modes