Study On Fracture Properties Of Carbon Nanotubes Aluminum Matrix Composites For Aerospace Inertial Devices

Aluminum matrix composites have many advantages of mechanical properties,such as low density,high specific strength,good plasticity,excellent electrical conductivity,thermal conductivity corrosion resistance and so on,so they are widely used in aerospace,automobile manufacturing,machinery manufacturing,shipbuilding and chemical industry.With the development of science and technology,carbon nanotubes(CNTs)as a new material with low density,high specific strength,high specific stiffness,low coefficient of thermal expansion and good thermal stability,have become the best choice for composite reinforcement Therefore,the mechanical properties of aluminum alloy matrix can be further improved by adding carbon nanotubes into aluminum alloy matrix by appropriate methods.This paper has introduced the research background,current situation and significance of carbon nanotubes,carbon nanotube composites and carbon nanotube aluminum matrix composites.And then it has clarified the research content of this paper.Furthermore,the paper has introduced the theoretical basis of carbon nanotubes aluminum matrix composites,including the continuum model of carbon nanotubes and the representative volume elements and micro-mechanics of carbon nanotubes aluminum matrix composites,which provides a theoretical basis for the study of fracture characteristics of carbon nanotubes aluminum matrix composites.Firstly the paper bases on the continuum theory,2024 aluminum alloy has been used as matrix to study the effect of carbon nanotubes with volume fractions of 2%,3%and 4%on the fracture characteristics of carbon nanotubes aluminum matrix composites.The results show that the volume fraction of carbon nanotubes has an important influence on the fracture characteristics of carbon nanotubes aluminum matrix composites.The results show that the elastic modulus,yield strength and shear modulus of the composites are positively correlated with the volume fraction of carbon nanotubes.When the volume fraction of carbon nanotubes is 4%,the elastic modulus,yield strength and shear modulus of carbon nanotubes aluminum matrix composites are 138.453GPa,396.37MPa and 51.7GPa,and comparing with the 2024 aluminum alloy,they have increased by 97.7%.27.86%and 106.8%respectively,which indicates that carbon nanotubes play a better reinforcing role in the aluminum matrix composites.Then the paper has studied the effect of carbon nanotubes with volume fraction of 2%,bending angles of 0°,15°,and 300 on the fracture characteristics of carbon nanotubes aluminum matrix composites.The results show that the fracture properties of carbon nanotubes aluminum matrix composites increase first and then decrease with the increase of bending angle of carbon nanotubes.When the angle of carbon nanotubes is 15°,the mechanical properties of carbon nanotubes aluminum matrix composites are the best.The elastic modulus,yield strength and shear modulus of carbon nanotubes Al matrix composites are 137.374GPa,400.29GPa and 51.122GPa,and comparing with the 2024 aluminum alloy,they have increased by 96.25%,29.12%and 104.49%respectively,which indicates that carbon nanotubes play a better reinforcing role in the aluminum matrix composites.Finally,the material properties of carbon nanotube aluminum matrix composites with good mechanical properties have been applied to the aerospace inertial device-aerospace accelerometer.By comparing with the original material,the advantages of carbon nanotube aluminum matrix composites are reflected.On the one hand,the weight of aerospace inertial devices is reduced,on the other hand,the navigation is reduced.The installation of the inertial device is deformed so as to improve the performance of the space accelerometer.