Study On Microstructure And Properties Of GPE_p-Ti/Al MIL Composite

Recently,with the progress ofthe economy and the improvement ofnational strength,the lives of people are getting richer,and the aerospace,military,and transportation industries are developing at a rapid pace.Therefore,materials continue to develop in order to satisfy the needs of different industries,such as aerospace.Among them,intermetallic compounds are widely concerned because of their excellent properties,such as high temperature resistance and corrosion resistance.However,it is constrained because plastic deformation will be inhibited and manifest as brittleness under the action of stress.In the 1990s,layered composites were widely studied.The special failure mode oflayered composites can effectively improve the brittleness of intermetallic compounds,but layered composites generally have the problem of poor plasticity at low temperatures.In addition,studies have shown that graphene has excellent properties and is very suitable as areinforcing material.In this work,graphene powder reinforced Ti-Al metal-intermetallic（GPE_p-Ti/Al）laminated composites were prepared by hot rolling and vacuum hot pressing sintering using graphene powder,titanium foil（TA1）and aluminum foil（1060Al）.The microstructure was characterized by X-Ray Diffraction（XRD）,Search Engine Marketing（SEM）,Energy Dispersive Spectroscopy（EDS）and Transmission Electron Microscope（TEM）.At the sintering temperature of 650°C,only the intermetallic compound Al3Ti is formed between the Ti layer and the Al layer.After characterizing the microstructure of this laminated composite,it was found that the interface between graphene and the aluminum layer was well bonded.The Al₃Tiparticles are obvious,showing a"polygonal"shape.The interface between the Al₃Ti layer and the Ti and Al layers is clear and well-bonded.The research on graphene powder reinforced Ti-Al metal-intermetallic laminated composite（GPE_p-Ti/Al laminated composite）shows that its density is 3.34g/cm³,which is a lightweight material.The average hardness of Ti layers,Al₃Ti layers and Al layers are144.6HV,509.2HV and 184HV,respectively.In addition,the ultimate tensile strength and elongation of the laminated composites were 224.85MPa and 24.15%,respectively.The tensile resistance of the sample is mainly determined by the Ti layer,and the large deformation of the Al layer enhances the deformation ability of the material.In the transverse compression tests,the transverse compressive strength of the laminated composite is 225.51MPa,and the Ti layers are bent and deformed under the load,which is the main stress layer.The average longitudinal compressive strength is235.55MPa,and the deformation of Al layers is larger.In the transverse three-point bending tests,the failure strain of the laminated composite material was 8.27%,the bending strength was 263.27MPa,and the layers of the sample were jointly stressed.The average bending strength of longitudinal three-point bending is about 157.83MPa,and the average failure strain is 6.72%.There are obvious interlaminar cracks at the Ti-Al interface and Al-Al interface.The single-edge notched three-point bending test shows that the fracture toughness KIC is 6.586MPa·m^1/2.The specimen cracks between the layers at the fracture,and the Ti and Allayers are necked due to the bending tensile stress.Through the above mechanical properties,it is found that GPE_p-Ti/Al laminated composites continue the toughness of the Ti layer and the Al layer and have excellent mechanical properties.Combined with the fracture morphology,it can be found that the crack mainly initiates at the interface between the layers and breaks under the load.The failure modes of Ti and Al layers are ductile fracture,and Al₃Ti layers are brittle fracture.