Determining temperatures and forces necessary to produce hot-pressed tubes out of titanium alloy PT-1M

Abstract

This paper describes the results of a study that looked at alloy PT-1M that refers to the Ti – Al system and the α-alloys of titanium and is used to make tubes for various applications, including tubes that are hot-pressed as part of the manufacturing process. When developing a procedure for making hot-pressed tubes, one should first determine the temperatures and forces of the pressing operation that would ensure production of quality semifinished tubes. By means of test quenching operations, optical microscopy, thermodynamic analysis performed in ThermoCalc and physical modelling of the hot deformation process carried out in Gleeble 3800, as well as a series of mathematical calculations, the authors were able to determine the polymorphic α + β → β transformation temperature, as well as temperature regions of heating and forces that are necessary for hot pressing of the titanium alloy PT-1M for producing tubes of a given size at the TMK Group facilities. Having analyzed the temperature region of the α + β → β transformation in alloy PT-1M through thermodynamic calculation in ThermoCalc, the authors came up with recommended test temperatures for the PT-1M alloy for estimating the hot deformation forces required. The authors simulated the process of hot deformation by compressing specimens of the PT-1M alloy in the recommended temperature range, explained how the forces changed as a function of temperature and true deformation rate and determined the maximum forces and the strain-induced heating. The calculations show that, in the temperature range recommended for pressing tubes of a given size from PT-1M workpieces, the peak loads do not exceed the capacity of the pipe press in view. This research was funded by the Russian Science Foundation (Project No. 18-79-10107).