Investigation of Nitinol Alloy Deformation Features in Temperature Range from 500 to 950°C

摘要

A basic technological scheme is provided for production of metal products from NiTiNOL alloy, including stages of workpiece manufacture, then a semi-finished product, and immediately an operation for providing a shape memory effect. Based on a literature review it is shown that there are no specific scientific and technical data for semi-finished product manufacturing regimes from NiTiNOL alloy. This confirms the aim of the present study to determine features of NiTiNOL alloy deformation (critical degree and permissible strain rate, ductility properties) and deformation resistance in the temperature range 500–950°С. In particular, the following problems are resolved: deformation and force conditions for NiTiNOL alloy upsetting and rolling are studied. The study is conducted in laboratory equipment of the site for experimental studies in RusNITI. Based on results of the study it is revealed that the rational temperature range for the pressing process is 700–750°С providing an acceptable level of NiTiNOL alloy deformation resistance, i.e., from 225 to 250 N/mm2. Considering features established for ductility properties and drawing capacity for NiTiNOL alloy implementation of rolling is rational in the temperature range 800–850°С.