Experimental Study On Mechanical Properties Of Tensile- Torsion Of Ti And Ni Based On Different Thermal Fields

The development of material science and technology is the symbol of a country’s strong comprehensive national strength, also is the forerunner of all sophisticated science and technology. As functional materials have an incomparable advantage compared with other structural materials characteristics, those developments are very rapid and applications have become more complex. Sometimes they work under a variety of mechanical loads, may be accompanied by the effect of multiple physical fields, for example thermal field, magnetic field and the electric field. Therefore, it is significant to carry out the material mechanics performance test research under materials working environment.In order to guide the application of functional materials, functional materials’ mechanical properties in the physical field are necessary to be understood. This paper selects the common Ti and Ni in memory alloy, which are widely used in aerospace and other fields, and applies multi-loads and multi-physics fields coupling material micro performance in-situ test and testing machine to study titanium and nickel’mechanical properties in different thermal fields under the action of tensile and torsion, funded by the major national science and technology development project. Research of this paper mainly is as follows:(1) this paper carried out tensile tests of metal Ti and Ni in the gradient temperature of 20℃,150℃,300℃,450℃ and made research on the effects of temperature field of Ti and Ni tensile at elastic stage, yield stage, strengthening stage and necking stage, and used Frank Rhett dislocation propagation theory to analyze material strain hardening characteristics of the yielding and hardening phenomenon. Finally, the yield strength, tensile strength and elongation of the tensile mechanical properties index with temperature changes were studied.(2) Carried out the torsion test of the metal Ti and Ni, respectively, in the gradient temperature 20℃,150℃,300℃,450℃. The effect of temperature field on the torsion test of Ti and Ni was studied, and the change of its torsion mechanical properties under different thermal fields was discussed.(3) Aimed at the action of a variety of mechanical loads, this paper launched tensile test of Ti and Ni in 0-4 π pre-torsion angle, and studied the impact on yield strength andπ tensile strength of Ti and Ni under pre-torsion.