The Study Of Backward Extrusion Process For Small Dimensional Titanium Alloy Tube

Ti-Ni shape-memory alloy is a new kind of functional material, along with the application of the Ti-Ni shape-memory alloy in industry, the study of Ti-Ni alloy seamless tube plastic forming technology is the one of hot research subjects today. As there is a bility of improving metal forming and producing integrated high-performance products, hot extrusion is an effective method in Ti-Ni shape-memory alloy processing.For the problem of small size titanium tube backward extrusion process, making theφ44×10.5 TiNiNb tube as the researching object and basing on large-scale nonliner finite element software DEFORM-3D, the tube backward extrusion forming process is simulated, the tube of TiNiNb alloy reversal extrusion forming mechanism is analysed.Basing on simulation results, analyse the technical parameters influences on load, the forming technological parameters that have powerful influence on the tube forming quality and load is screened out.Accordingly, the influence rules are discussed which the most forming technological parameters impact equivalent strain, equivalent stress and extrusion force.The reversal extrusion force and unit extrusion force calculating formula is derived by the balanced work method. The veracity of expression is validated by experimental data. The quantity of heat transforming instance of the tube is simulated by thermal-mechanical coupling model of numerical simulation software. Accordingly, the extrusion limit diagram is made, which can reflect quantitative realations between extrusion force, temperature of tube in die orifice and extrusionvelocity, temperature of billet.Basing on analysis ofφ44×10.5 TiNiNb tube extrusion process, the backward extrusion experimental die is designed and has been manufactured. Theφ44×10.5 TiNiNb tube backward extrusion experimental scheme is made finally.