Study On The Application Of Shape Memory Alloy Alloy In Self-healing Behaviors Of Zinc Based Alloy

Self-healing alloy have attracted an increasing attention in the field of aerospace and military due to their special performance,such as repair the damage of the material and extend the service life of equipment.Fatigue fracture is an important problem in the application of aerospace materials.In recent years,Self-healing material have attracted people' attention with the ability to mitigate the fracture of the material.The composite materials composed of NiTi shape memory alloy wires and zinc base alloy were prepared.When the composite materials fatigue fracture occurred,the destruction of the metal matrix were slowing down due to the super elasticity and shape memory effect of NiTi shape memory alloy.When the fracture composite material were heated to the phase transition temperature of the shape memory alloy wire,the crack of composite will be closed due to the shape memory effect of shape memory alloy wires.And the self-healing process will be ended by the re-melt of the surface of the composite in the condition of high temperature.In this paper,the shape memory composite materials composed of NiTi shape memory alloy wires and zinc base alloy were prepared,which shows the ability of self-healing.The micro structure,phase composition,mechanical properties of the shape memory composite materials were analyzed by optical microscope,X-ray diffraction,scanning electron microscopy,energy dispersive spectroscopy and cupping machine.The principle of the application of shape memory alloy in self-healing behavior of zinc based alloy were investigated.At the same time,the effects of the volume fraction of NiTi alloy wires,heating temperature,holding time on mechanical properties of shape memory alloy composite material were investigated.Finally,the efficiency of self-healing of the composite materials were evaluated.The results show that the bonding strength of NiTi alloy wires and Zinc alloy in composite materials were changed with the change of the parameters such as heating temperature,holding time.When the heating temperature is 460 ?,holding time is 60 minutes,the composite material has the best mechanical properties.By analysis the self-healing mechanism of shape memory alloy composite material found that,the realization of the self-healing function is used the shape memory effects and partial melting which is caused by heating the shape memory composite materials.The mechanical test of self-healing materials show that the self-healing efficiency increased with the increase of the volume fraction of NiTi alloy wires,the self-healing rate can reach 56.43% with the content of NiTi alloy wires is 4.5%.Also found that the self-healing rate of the composite materials is affected by the healing temperature,the low efficiency of self-healing is showed with healing temperature under 384?;The surface of metal matix will be excessive melted with healing temperature above 394?.