Study On Crack Behavior Of Thick Titanium Alloy Plate Under High Energy Laser Loading

It's often required the materials and structures to be in extreme conditions in aerospace and deep-sea scientific research or military fields.TC4 titanium alloy is a structural metal with high strength,high temperature resistance,corrosion resistance and strong plasticity,which is widely used in the above fields.Therefore,the study of damage and spallation of titanium alloy materials and structures plays an important roleis not only in the national economy,but also in the development of science and technology of a country.The ABAQUS simulation software was used to build the TC4 titanium alloy model loaded nanofemtosecond laser and the effects of the above parameters on the cracking behavior of TC4 titanium alloy metal target were discussed by adjusting the single pulse energy,laser radius and target thickness of the laser.The calculation results of the nanofemtosecond laser-loaded metal material model show that the larger the single-pulse energy of the laser and the larger the spot diameter,the smaller the thickness of the target thickness,and the target is prone to delamination damage behavior.The work of this paper is as follows:(1)The interaction mechanism between nano femtosecond laser and metal materials was analyzed,and the difference between the two was compared.The mechanism of the cracking damage of metal materials was analyzed.(2)The TC4 titanium alloy model loaded by nanofemtosecond laser laser was built by ABAQUS simulation software.The effects of the above parameters on the crack damage behavior of TC4 titanium alloy metal target were discussed by adjusting the single pulse energy,laser radius and target thickness of the laser.The calculation results of the nano-femotosecond laser-loaded metal material model show that the larger the single-pulse energy of the laser and the larger the spot diameter,the smaller the thickness of the target thickness,and the target is prone to delamination damage behavior.(3)According to the simulation model,the corresponding nanofemtosecond laser loading TC4 target experiment was carried out in the laboratory.The damage of the surface of TC4 titanium alloy target was observed by electron microscopy of the recovered target,and the damage cracking result of TC4 titanium alloy target under extremely high strain rate loading was obtained.Among them,when the target thickness is 0.05 mm,the target has cracking behavior under nanosecond laser loading.While under the femtosecond laser loading,the laser processing parameters are used,and the target is in the range of 0.01mm-0.1mm thickness,and the micro-layer crack morphology and the cavity growth,connectivity and crack growth and extension in the pre-cracking stage are obtained,which proves that the mechanical effect of the femtosecond laser interacting with the metal material can cause the surface damage cracking behavior of the metal target.The research results obtained in this paper can provide data and experience accumulation for the study of deformation cracking of TC4 titanium alloy under high energy laser loading,and also provide data and method reference for TC4 titanium alloy metal in aviation military field and its industrial processing.