Numerical Simulation And Engineering Study And Numerical Simulation On Extrusion Process Of NiTiNb Shape Memory Alloy Tubes

NiTiNb alloy has excellent corrosion resistance, good tensile strength, fatigue strength,plastic forming performance and corrosion resistance and many excellent comprehensiveperformances, It boasts a wide range of applications with high value in engineering andbiological communities, especially for its superior shape memory and biologicalcompatibility. However nickel titanium alloys has a narrow range in deformationtemperature. Its temperature drop too fast in the deformation resistance and it has strongplastic deformation process and poor rheological property. Then processing is more difficultwith a higher processing cost. Processing and manufacturing of nickel titanium alloymolding has become a challenge.The research object of this paper is38Ti48Ni14Nb. This paper introduces thecharacteristics, applications and the sheathed extrusion technology of the alloy withDEFORM-3D, the finite element numerical simulation technology based on theexperimental data and experience to ensure the stress, strain and the relation betweentemperature and strain rate of38Ti48Ni14Nb in the sheathed alloy extrusion numericalsimulation process, design model features, select the extrusion process parameters, andadjust the heat transfer coefficient and the friction coefficient. The next step is calculating φ40-5mm pipes to bag set of hot extrusion numerical simulation and focusing on the analysisof the size of the tube extrusion, change trend, equivalent stress, the equivalent straindistribution, the metal flow speed and temperature distribution in three stages of theextrusion processes.Through designing different extrusion process parameters on the materials forextrusion numerical simulation. Under the condition of only changing one parameter of thenumerical, I compare and analyse the tube billet heating temperature, extrusion speed,extrusion ratio, steel tube extrusion pressure, the outlet temperature and the influence of thechanging rules of the blank equivalent stress. Then I summarize the reasonable range ofNiTiNb alloy extrusion of package process parameters. Within the scope of extrusionprocess parameters, I summarize38Ti48Ni14Nb alloy extrusion process without bag setnumerical simulation, and further explained the superiority of the extrusion in order tooptimize provide nb theory and technical support the nickel titanium alloy pipe extrusionprocess. Doing the experiments on NiTiNb alloy pipe to testify the feasibility of extrusion of bag process.