Study On Preparation And Properties Of Ti/Al₃Ti Laminated Composites By "Explosive Welding + Heat Treatment"

Ti/Al₃Ti laminated composites have been widely used in aerospace and armor protection fields because of their high specific stiffness,high specific strength,high elastic modulus,good corrosion resistance and low density..As the traditional main method of preparing laminated composites,hot pressing is limited by the size of the die,while explosive welding is widely used because of its simple operation and unlimited size.In this paper,Ti/Al₃Ti laminated composites were prepared by“explosive welding+heat treatment”.In order to compare the effects of different charge height and heat treatment temperature on the materials,the micro-interface,mechanical properties and fracture mechanism of laminated materials are studied in this paper.the main contents and conclusions are as follows:(1)Ti/Al laminated composites were prepared by explosive welding and Ti/Al₃Ti laminated composites were prepared at 710?and 665?.The bonding surface of Ti/Al₃Ti and Ti/Al laminated composites was observed by metallographic microscope.The results show that the bonding quality of Ti/Al material under 20 mm charge height is the best,Ti/Al₃Ti material prepared at 710?has fewer pores,but the Al₃Ti layer thickness is lower than that of the laminated material prepared at 665?.(2)The room temperature tensile test of Ti/Al material was carried out by universal testing machine.The results show that the tensile property of Ti/Al material under 20 mm charge height and 1.0 mm interlayer is the best,and the tensile strength reaches 354 MPa.The dynamic compression experiments of Ti/Al material and Ti/Al₃Ti material were carried out by split Hopkinson pressure bar device.The results showed that the compressive properties of Ti/Al materials decreased slightly after heat treatment at 710?,and greatly improved after heat treatment at 665?.(3)The fracture process and mechanism of Ti/Al₃Ti are studied by in-situ stretching experiment.the results show that the ductile Ti layer will restrain the brittle Al₃Ti during the tensile process,and the crack will appear first in the Al₃Ti layer,and the crack will deflect and when it meets the ductile Ti layer,so as to make the laminated material absorb more tensile stress and enhance the tensile properties of the material.