The Study Of Backward Extrusion Process For Ti-Ni Alloy Tube

Along with the application of the Ti-Ni shape memory alloy as a new-style functional material in industry, the study of Ti-Ni alloy seamless tube plastic forming technology is the one of the hot research subjects today.As there was a bility of improving metal forming and producing integrated high-performance products, hot extrusion is a effective method in Ti-Ni shape memory alloy processing.Taking into consideration of manifold factors,such as heat conduction,heat convection,fricional heat,plastic work done etc,Studied backward extrusion process forφ44×10.5mm TiNiNb alloy tube,and analysed the deformation behaviour of metal and the state of stress of die in process of backward extrusion,making use of rigid-plastic FEM model in Marc. Basing of which, optimum designed the female die and extrusion container.First of all,discussed the structure of extrusion female die,established the specific simulated parameter and analysed the effect of structure of female die on extrusion process. Known from analysis that modular angle of extrusion female die was the more important factor in impacting the extrusion process than that of lenth of calibrating strap and radius of corner,which had an major effect on extrusion force,flow of metal and extrusion deformation.Basing of which,established structure parameters of female die and designed the experimental extrusion female die.Then showed the theoretical basis,clarified the flow and the specific method of extrusion container analysis.Analysis commenced with one-layer extrusion container and established the FEM model of circle extrusion container, checked the strength of extrusion container and illuminated the reasonable scheme which is two-layer unitized circular extrusion container and designed experimental extrusion container. And then analysed the regularities of distribution of kinds of strsses and temperature.